├── .gitignore ├── README.org ├── cheatsheet-kubernetes-A4.pdf ├── get-pod-error-log.sh ├── jenkinjavafile ├── k8s-networking-ip.png ├── list-all-images.sh └── skip-tls-verify.md /.gitignore: -------------------------------------------------------------------------------- 1 | *.tex 2 | README.pdf 3 | .DS_Store 4 | *-A4.log 5 | -------------------------------------------------------------------------------- /README.org: -------------------------------------------------------------------------------- 1 | * Kubectl Kubernetes CheatSheet :Cloud: 2 | :PROPERTIES: 3 | :type: kubernetes 4 | :export_file_name: cheatsheet-kubernetes-A4.pdf 5 | :END: 6 | 7 | #+BEGIN_HTML 8 |

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17 | #+END_HTML 18 | 19 | - PDF Link: [[https://github.com/dennyzhang/cheatsheet-kubernetes-A4/blob/master/cheatsheet-kubernetes-A4.pdf][cheatsheet-kubernetes-A4.pdf]], Category: [[https://cheatsheet.dennyzhang.com/category/cloud/][Cloud]] 20 | - Blog URL: https://cheatsheet.dennyzhang.com/cheatsheet-kubernetes-A4 21 | - Related posts: [[https://cheatsheet.dennyzhang.com/cheatsheet-kubernetes-A4][Kubectl CheatSheet]], [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Kubernetes Yaml]], [[https://github.com/topics/denny-cheatsheets][#denny-cheatsheets]] 22 | 23 | File me [[https://github.com/dennyzhang/cheatsheet.dennyzhang.com/issues][Issues]] or star [[https://github.com/dennyzhang/cheatsheet.dennyzhang.com][this repo]]. 24 | ** Common Commands 25 | | Name | Command | 26 | |--------------------------------------+-------------------------------------------------------------------------------------------| 27 | | Run curl test temporarily | =kubectl run --generator=run-pod/v1 --rm mytest --image=yauritux/busybox-curl -it= | 28 | | Run wget test temporarily | =kubectl run --generator=run-pod/v1 --rm mytest --image=busybox -it wget= | 29 | | Run nginx deployment with 2 replicas | =kubectl run my-nginx --image=nginx --replicas=2 --port=80= | 30 | | Run nginx pod and expose it | =kubectl run my-nginx --restart=Never --image=nginx --port=80 --expose= | 31 | | Run nginx deployment and expose it | =kubectl run my-nginx --image=nginx --port=80 --expose= | 32 | | List authenticated contexts | =kubectl config get-contexts=, =~/.kube/config= | 33 | | Set namespace preference | =kubectl config set-context --namespace== | 34 | | List pods with nodes info | =kubectl get pod -o wide= | 35 | | List everything | =kubectl get all --all-namespaces= | 36 | | Get all services | =kubectl get service --all-namespaces= | 37 | | Get all deployments | =kubectl get deployments --all-namespaces= | 38 | | Show nodes with labels | =kubectl get nodes --show-labels= | 39 | | Get resources with json output | =kubectl get pods --all-namespaces -o json= | 40 | | Validate yaml file with dry run | =kubectl create --dry-run --validate -f pod-dummy.yaml= | 41 | | Start a temporary pod for testing | =kubectl run --rm -i -t --image=alpine test-$RANDOM -- sh= | 42 | | kubectl run shell command | =kubectl exec -it mytest -- ls -l /etc/hosts= | 43 | | Get system conf via configmap | =kubectl -n kube-system get cm kubeadm-config -o yaml= | 44 | | Get deployment yaml | =kubectl -n denny-websites get deployment mysql -o yaml= | 45 | | Explain resource | =kubectl explain pods=, =kubectl explain svc= | 46 | | Watch pods | =kubectl get pods -n wordpress --watch= | 47 | | Query healthcheck endpoint | =curl -L http://127.0.0.1:10250/healthz= | 48 | | Open a bash terminal in a pod | =kubectl exec -it storage sh= | 49 | | Check pod environment variables | =kubectl exec redis-master-ft9ex env= | 50 | | Enable kubectl shell autocompletion | =echo "source <(kubectl completion bash)" >>~/.bashrc=, and reload | 51 | | Use minikube dockerd in your laptop | =eval $(minikube docker-env)=, No need to push docker hub any more | 52 | | Kubectl apply a folder of yaml files | =kubectl apply -R -f .= | 53 | | Get services sorted by name | kubectl get services --sort-by=.metadata.name | 54 | | Get pods sorted by restart count | kubectl get pods --sort-by='.status.containerStatuses[0].restartCount' | 55 | | List pods and images | kubectl get pods -o='custom-columns=PODS:.metadata.name,Images:.spec.containers[*].image' | 56 | | List all container images | [[https://github.com/dennyzhang/cheatsheet-kubernetes-A4/blob/master/list-all-images.sh#L14-L17][list-all-images.sh]] | 57 | | kubeconfig skip tls verification | [[https://github.com/dennyzhang/cheatsheet-kubernetes-A4/blob/master/skip-tls-verify.md][skip-tls-verify.md]] | 58 | | [[https://kubernetes.io/docs/tasks/tools/install-kubectl/][Ubuntu install kubectl]] | ="deb https://apt.kubernetes.io/ kubernetes-xenial main"= | 59 | | Reference | [[https://github.com/kubernetes/kubernetes/tags][GitHub: kubernetes releases]] | 60 | | Reference | [[https://cheatsheet.dennyzhang.com/cheatsheet-minikube-A4][minikube cheatsheet]], [[https://cheatsheet.dennyzhang.com/cheatsheet-docker-A4][docker cheatsheet]], [[https://cheatsheet.dennyzhang.com/cheatsheet-openshift-A4][OpenShift CheatSheet]] | 61 | ** Check Performance 62 | | Name | Command | 63 | |----------------------------------------------+------------------------------------------------------| 64 | | Get node resource usage | =kubectl top node= | 65 | | Get pod resource usage | =kubectl top pod= | 66 | | Get resource usage for a given pod | =kubectl top --containers= | 67 | | List resource utilization for all containers | =kubectl top pod --all-namespaces --containers=true= | 68 | ** Resources Deletion 69 | | Name | Command | 70 | |-----------------------------------------+----------------------------------------------------------| 71 | | Delete pod | =kubectl delete pod/ -n = | 72 | | Delete pod by force | =kubectl delete pod/ --grace-period=0 --force= | 73 | | Delete pods by labels | =kubectl delete pod -l env=test= | 74 | | Delete deployments by labels | =kubectl delete deployment -l app=wordpress= | 75 | | Delete all resources filtered by labels | =kubectl delete pods,services -l name=myLabel= | 76 | | Delete resources under a namespace | =kubectl -n my-ns delete po,svc --all= | 77 | | Delete persist volumes by labels | =kubectl delete pvc -l app=wordpress= | 78 | | Delete state fulset only (not pods) | =kubectl delete sts/ --cascade=false= | 79 | #+BEGIN_HTML 80 |

81 | #+END_HTML 82 | ** Log & Conf Files 83 | | Name | Comment | 84 | |---------------------------+---------------------------------------------------------------------------| 85 | | Config folder | =/etc/kubernetes/= | 86 | | Certificate files | =/etc/kubernetes/pki/= | 87 | | Credentials to API server | =/etc/kubernetes/kubelet.conf= | 88 | | Superuser credentials | =/etc/kubernetes/admin.conf= | 89 | | kubectl config file | =~/.kube/config= | 90 | | Kubernetes working dir | =/var/lib/kubelet/= | 91 | | Docker working dir | =/var/lib/docker/=, =/var/log/containers/= | 92 | | Etcd working dir | =/var/lib/etcd/= | 93 | | Network cni | =/etc/cni/net.d/= | 94 | | Log files | =/var/log/pods/= | 95 | | log in worker node | =/var/log/kubelet.log=, =/var/log/kube-proxy.log= | 96 | | log in master node | =kube-apiserver.log=, =kube-scheduler.log=, =kube-controller-manager.log= | 97 | | Env | =/etc/systemd/system/kubelet.service.d/10-kubeadm.conf= | 98 | | Env | export KUBECONFIG=/etc/kubernetes/admin.conf | 99 | ** Pod 100 | | Name | Command | 101 | |------------------------------+-------------------------------------------------------------------------------------------| 102 | | List all pods | =kubectl get pods= | 103 | | List pods for all namespace | =kubectl get pods --all-namespaces= | 104 | | List all critical pods | =kubectl get -n kube-system pods -a= | 105 | | List pods with more info | =kubectl get pod -o wide=, =kubectl get pod/ -o yaml= | 106 | | Get pod info | =kubectl describe pod/srv-mysql-server= | 107 | | List all pods with labels | =kubectl get pods --show-labels= | 108 | | [[https://github.com/kubernetes/kubernetes/issues/49387][List all unhealthy pods]] | kubectl get pods --field-selector=status.phase!=Running --all-namespaces | 109 | | List running pods | kubectl get pods --field-selector=status.phase=Running | 110 | | Get Pod initContainer status | =kubectl get pod --template '{{.status.initContainerStatuses}}' = | 111 | | kubectl run command | kubectl exec -it -n "$ns" "$podname" -- sh -c "echo $msg >>/dev/err.log" | 112 | | Watch pods | =kubectl get pods -n wordpress --watch= | 113 | | Get pod by selector | kubectl get pods --selector="app=syslog" -o jsonpath='{.items[*].metadata.name}' | 114 | | List pods and images | kubectl get pods -o='custom-columns=PODS:.metadata.name,Images:.spec.containers[*].image' | 115 | | List pods and containers | -o='custom-columns=PODS:.metadata.name,CONTAINERS:.spec.containers[*].name' | 116 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]] | 117 | ** Label & Annotation 118 | | Name | Command | 119 | |----------------------------------+-------------------------------------------------------------------| 120 | | Filter pods by label | =kubectl get pods -l owner=denny= | 121 | | Manually add label to a pod | =kubectl label pods dummy-input owner=denny= | 122 | | Remove label | =kubectl label pods dummy-input owner-= | 123 | | Manually add annotation to a pod | =kubectl annotate pods dummy-input my-url=https://dennyzhang.com= | 124 | ** Deployment & Scale 125 | | Name | Command | 126 | |------------------------------+--------------------------------------------------------------------------| 127 | | Scale out | =kubectl scale --replicas=3 deployment/nginx-app= | 128 | | online rolling upgrade | =kubectl rollout app-v1 app-v2 --image=img:v2= | 129 | | Roll backup | =kubectl rollout app-v1 app-v2 --rollback= | 130 | | List rollout | =kubectl get rs= | 131 | | Check update status | =kubectl rollout status deployment/nginx-app= | 132 | | Check update history | =kubectl rollout history deployment/nginx-app= | 133 | | Pause/Resume | =kubectl rollout pause deployment/nginx-deployment=, =resume= | 134 | | Rollback to previous version | =kubectl rollout undo deployment/nginx-deployment= | 135 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]], [[https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#pausing-and-resuming-a-deployment][Link: Pausing and Resuming a Deployment]] | 136 | #+BEGIN_HTML 137 |

138 | #+END_HTML 139 | ** Quota & Limits & Resource 140 | | Name | Command | 141 | |-------------------------------+-------------------------------------------------------------------------| 142 | | List Resource Quota | =kubectl get resourcequota= | 143 | | List Limit Range | =kubectl get limitrange= | 144 | | Customize resource definition | =kubectl set resources deployment nginx -c=nginx --limits=cpu=200m= | 145 | | Customize resource definition | =kubectl set resources deployment nginx -c=nginx --limits=memory=512Mi= | 146 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]] | 147 | ** Service 148 | | Name | Command | 149 | |---------------------------------+-----------------------------------------------------------------------------------| 150 | | List all services | =kubectl get services= | 151 | | List service endpoints | =kubectl get endpoints= | 152 | | Get service detail | =kubectl get service nginx-service -o yaml= | 153 | | Get service cluster ip | kubectl get service nginx-service -o go-template='{{.spec.clusterIP}}' | 154 | | Get service cluster port | kubectl get service nginx-service -o go-template='{{(index .spec.ports 0).port}}' | 155 | | Expose deployment as lb service | =kubectl expose deployment/my-app --type=LoadBalancer --name=my-service= | 156 | | Expose service as lb service | =kubectl expose service/wordpress-1-svc --type=LoadBalancer --name=ns1= | 157 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]] | 158 | ** Secrets 159 | | Name | Command | 160 | |----------------------------------+-------------------------------------------------------------------------| 161 | | List secrets | =kubectl get secrets --all-namespaces= | 162 | | Generate secret | =echo -n 'mypasswd', then redirect to base64 --decode= | 163 | | Get secret | =kubectl get secret denny-cluster-kubeconfig= | 164 | | Get a specific field of a secret | kubectl get secret denny-cluster-kubeconfig -o jsonpath="{.data.value}" | 165 | | Create secret from cfg file | kubectl create secret generic db-user-pass --from-file=./username.txt | 166 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]], [[https://kubernetes.io/docs/concepts/configuration/secret/][Link: Secrets]] | 167 | ** StatefulSet 168 | | Name | Command | 169 | |------------------------------------+----------------------------------------------------------| 170 | | List statefulset | =kubectl get sts= | 171 | | Delete statefulset only (not pods) | =kubectl delete sts/ --cascade=false= | 172 | | Scale statefulset | =kubectl scale sts/ --replicas=5= | 173 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]] | 174 | ** Volumes & Volume Claims 175 | | Name | Command | 176 | |---------------------------+--------------------------------------------------------------| 177 | | List storage class | =kubectl get storageclass= | 178 | | Check the mounted volumes | =kubectl exec storage ls /data= | 179 | | Check persist volume | =kubectl describe pv/pv0001= | 180 | | Copy local file to pod | =kubectl cp /tmp/my /:/tmp/server= | 181 | | Copy pod file to local | =kubectl cp /:/tmp/server /tmp/my= | 182 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]] | 183 | ** Events & Metrics 184 | | Name | Command | 185 | |---------------------------------+------------------------------------------------------------| 186 | | View all events | =kubectl get events --all-namespaces= | 187 | | List Events sorted by timestamp | kubectl get events --sort-by=.metadata.creationTimestamp | 188 | ** Node Maintenance 189 | | Name | Command | 190 | |-------------------------------------------+-------------------------------| 191 | | Mark node as unschedulable | =kubectl cordon $NODE_NAME= | 192 | | Mark node as schedulable | =kubectl uncordon $NODE_NAME= | 193 | | Drain node in preparation for maintenance | =kubectl drain $NODE_NAME= | 194 | ** Namespace & Security 195 | | Name | Command | 196 | |-------------------------------+-----------------------------------------------------------------------------------------------------| 197 | | List authenticated contexts | =kubectl config get-contexts=, =~/.kube/config= | 198 | | Set namespace preference | =kubectl config set-context --namespace== | 199 | | Switch context | =kubectl config use-context = | 200 | | Load context from config file | =kubectl get cs --kubeconfig kube_config.yml= | 201 | | Delete the specified context | =kubectl config delete-context = | 202 | | List all namespaces defined | =kubectl get namespaces= | 203 | | List certificates | =kubectl get csr= | 204 | | [[https://kubernetes.io/docs/concepts/policy/pod-security-policy/][Check user privilege]] | kubectl --as=system:serviceaccount:ns-denny:test-privileged-sa -n ns-denny auth can-i use pods/list | 205 | | [[https://kubernetes.io/docs/concepts/policy/pod-security-policy/][Check user privilege]] | =kubectl auth can-i use pods/list= | 206 | | Reference | [[https://cheatsheet.dennyzhang.com/kubernetes-yaml-templates][Link: kubernetes yaml templates]] | 207 | ** Network 208 | | Name | Command | 209 | |-----------------------------------+----------------------------------------------------------| 210 | | Temporarily add a port-forwarding | =kubectl port-forward redis-134 6379:6379= | 211 | | Add port-forwarding for deployment | =kubectl port-forward deployment/redis-master 6379:6379= | 212 | | Add port-forwarding for replicaset | =kubectl port-forward rs/redis-master 6379:6379= | 213 | | Add port-forwarding for service | =kubectl port-forward svc/redis-master 6379:6379= | 214 | | Get network policy | =kubectl get NetworkPolicy= | 215 | | Get ingress controller | =kubectl get ingress= | 216 | | Get ingress classes | =kubectl get ingressclasses= | 217 | ** Patch 218 | | Name | Summary | 219 | |-------------------------------+---------------------------------------------------------------------| 220 | | Patch service to loadbalancer | kubectl patch svc $svc_name -p '{"spec": {"type": "LoadBalancer"}}' | 221 | ** Extenstions 222 | | Name | Summary | 223 | |-----------------------------------------+----------------------------| 224 | | Enumerates the resource types available | =kubectl api-resources= | 225 | | List api group | =kubectl api-versions= | 226 | | List all CRD | =kubectl get crd= | 227 | | List storageclass | =kubectl get storageclass= | 228 | #+BEGIN_HTML 229 |

230 | #+END_HTML 231 | ** Components & Services 232 | *** Services on Master Nodes 233 | | Name | Summary | 234 | |--------------------------+--------------------------------------------------------------------------------------------| 235 | | [[https://github.com/kubernetes/kubernetes/tree/master/cmd/kube-apiserver][kube-apiserver]] | API gateway. Exposes the Kubernetes API from master nodes | 236 | | [[https://coreos.com/etcd/][etcd]] | reliable data store for all k8s cluster data | 237 | | [[https://github.com/kubernetes/kubernetes/tree/master/cmd/kube-scheduler][kube-scheduler]] | schedule pods to run on selected nodes | 238 | | [[https://github.com/kubernetes/kubernetes/tree/master/cmd/kube-controller-manager][kube-controller-manager]] | Reconcile the states. node/replication/endpoints/token controller and service account, etc | 239 | | cloud-controller-manager | | 240 | *** Services on Worker Nodes 241 | | Name | Summary | 242 | |-------------------+----------------------------------------------------------------------------------------------| 243 | | [[https://github.com/kubernetes/kubernetes/tree/master/cmd/kubelet][kubelet]] | A node agent makes sure that containers are running in a pod | 244 | | [[https://github.com/kubernetes/kubernetes/tree/master/cmd/kube-proxy][kube-proxy]] | Manage network connectivity to the containers. e.g, iptable, ipvs | 245 | | [[https://github.com/docker/engine][Container Runtime]] | Kubernetes supported runtimes: dockerd, cri-o, runc and any [[https://github.com/opencontainers/runtime-spec][OCI runtime-spec]] implementation. | 246 | 247 | *** Addons: pods and services that implement cluster features 248 | | Name | Summary | 249 | |-------------------------------+---------------------------------------------------------------------------| 250 | | DNS | serves DNS records for Kubernetes services | 251 | | Web UI | a general purpose, web-based UI for Kubernetes clusters | 252 | | Container Resource Monitoring | collect, store and serve container metrics | 253 | | Cluster-level Logging | save container logs to a central log store with search/browsing interface | 254 | 255 | *** Tools 256 | | Name | Summary | 257 | |-----------------------+-------------------------------------------------------------| 258 | | [[https://github.com/kubernetes/kubernetes/tree/master/cmd/kubectl][kubectl]] | the command line util to talk to k8s cluster | 259 | | [[https://github.com/kubernetes/kubernetes/tree/master/cmd/kubeadm][kubeadm]] | the command to bootstrap the cluster | 260 | | [[https://kubernetes.io/docs/reference/setup-tools/kubefed/kubefed/][kubefed]] | the command line to control a Kubernetes Cluster Federation | 261 | | Kubernetes Components | [[https://kubernetes.io/docs/concepts/overview/components/][Link: Kubernetes Components]] | 262 | ** More Resources 263 | License: Code is licensed under [[https://www.dennyzhang.com/wp-content/mit_license.txt][MIT License]]. 264 | 265 | https://kubernetes.io/docs/reference/kubectl/cheatsheet/ 266 | 267 | https://codefresh.io/kubernetes-guides/kubernetes-cheat-sheet/ 268 | 269 | #+BEGIN_HTML 270 |

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276 | #+END_HTML 277 | * org-mode configuration :noexport: 278 | #+STARTUP: overview customtime noalign logdone showall 279 | #+DESCRIPTION: 280 | #+KEYWORDS: 281 | #+LATEX_HEADER: \usepackage[margin=0.6in]{geometry} 282 | #+LaTeX_CLASS_OPTIONS: [8pt] 283 | #+LATEX_HEADER: \usepackage[english]{babel} 284 | #+LATEX_HEADER: \usepackage{lastpage} 285 | #+LATEX_HEADER: \usepackage{fancyhdr} 286 | #+LATEX_HEADER: \pagestyle{fancy} 287 | #+LATEX_HEADER: \fancyhf{} 288 | #+LATEX_HEADER: \rhead{Updated: \today} 289 | #+LATEX_HEADER: \rfoot{\thepage\ of \pageref{LastPage}} 290 | #+LATEX_HEADER: \lfoot{\href{https://github.com/dennyzhang/cheatsheet-kubernetes-A4}{GitHub: https://github.com/dennyzhang/cheatsheet-kubernetes-A4}} 291 | #+LATEX_HEADER: \lhead{\href{https://cheatsheet.dennyzhang.com/cheatsheet-kubernetes-A4}{Blog URL: https://cheatsheet.dennyzhang.com/cheatsheet-kubernetes-A4}} 292 | #+AUTHOR: Denny Zhang 293 | #+EMAIL: denny@dennyzhang.com 294 | #+TAGS: noexport(n) 295 | #+PRIORITIES: A D C 296 | #+OPTIONS: H:3 num:t toc:nil \n:nil @:t ::t |:t ^:t -:t f:t *:t <:t 297 | #+OPTIONS: TeX:t LaTeX:nil skip:nil d:nil todo:t pri:nil tags:not-in-toc 298 | #+EXPORT_EXCLUDE_TAGS: exclude noexport 299 | #+SEQ_TODO: TODO HALF ASSIGN | DONE BYPASS DELEGATE CANCELED DEFERRED 300 | #+LINK_UP: 301 | #+LINK_HOME: 302 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 303 | * DONE Misc scripts :noexport: 304 | CLOSED: [2018-11-17 Sat 12:23] 305 | - Tail pod log by label 306 | #+BEGIN_SRC sh 307 | namespace="mynamespace" 308 | mylabel="app=mylabel" 309 | kubectl get pod -l "$mylabel" -n "$namespace" | tail -n1 \ 310 | | awk -F' ' '{print $1}' | xargs -I{} \ 311 | kubectl logs -n "$namespace" -f {} 312 | #+END_SRC 313 | 314 | - Get node hardware resource utilization 315 | #+BEGIN_SRC sh 316 | kubectl get nodes --no-headers \ 317 | | awk '{print $1}' | xargs -I {} \ 318 | sh -c 'echo {}; kubectl describe node {} | grep Allocated -A 5' 319 | 320 | kubectl get nodes --no-headers | awk '{print $1}' | xargs -I {} \ 321 | sh -c 'echo {}; kubectl describe node {} | grep Allocated -A 5 \ 322 | | grep -ve Event -ve Allocated -ve percent -ve -- ; echo' 323 | #+END_SRC 324 | 325 | - Apply the configuration in manifest.yaml and delete all the other configmaps that are not in the file. 326 | 327 | #+BEGIN_EXAMPLE 328 | kubectl apply --prune -f manifest.yaml --all --prune-whitelist=core/v1/ConfigMap 329 | #+END_EXAMPLE 330 | * [#A] Kubernetes :noexport:IMPORTANT: 331 | https://github.com/dennyzhang/cheatsheet-kubernetes-A4 332 | 333 | k8s provides declarative primitives for the "desired state" 334 | - Self-healing 335 | - Horizontal scaling 336 | - Automatic binpacking 337 | - Service discovery and load balancing 338 | ** Names of certificates files 339 | https://github.com/kubernetes/kubeadm/blob/master/docs/design/design_v1.9.md 340 | Names of certificates files: 341 | ca.crt, ca.key (CA certificate) 342 | apiserver.crt, apiserver.key (API server certificate) 343 | apiserver-kubelet-client.crt, apiserver-kubelet-client.key (client certificate for the apiservers to connect to the kubelets securely) 344 | sa.pub, sa.key (a private key for signing ServiceAccount ) 345 | front-proxy-ca.crt, front-proxy-ca.key (CA for the front proxy) 346 | front-proxy-client.crt, front-proxy-client.key (client cert for the front proxy client) 347 | ** TODO update k8s cheatsheet github: https://github.com/alex1x/kubernetes-cheatsheet 348 | ** TODO Setting up MySQL Replication Clusters in Kubernetes: https://blog.kublr.com/setting-up-mysql-replication-clusters-in-kubernetes-ab7cbac113a5 349 | ** TODO MySQL on Docker: Running Galera Cluster on Kubernetes 350 | https://severalnines.com/blog/mysql-docker-running-galera-cluster-kubernetes 351 | ** TODO Try Functions as a Service - a serverless framework for Docker & Kubernetes http://docs.get-faas.com/ 352 | https://blog.alexellis.io/first-faas-python-function/ 353 | ** TODO [#A] k8s clustering elasticsearch 354 | https://blog.alexellis.io/kubernetes-kubeadm-video/ 355 | ** TODO k8s scale with redis 356 | ** TODO k8s scale with mysqld 357 | ** TODO [#A] k8s: https://5pi.de/2016/11/20/15-producation-grade-kubernetes-cluster/ 358 | ** TODO Try kops with k8s 359 | ** TODO k8s free course: https://classroom.udacity.com/courses/ud615 360 | ** TODO feedbackup for k8s study project 361 | Aaron Mulholland [1:18 AM] 362 | So it looks pretty good. Got some good concepts in early on. Couple of suggestions for further work; 363 | 364 | Potentially the following scenarios; 365 | * Setting up ingresses and TLS 366 | * Fully configure something like Nginx Ingress Controller or Traefik. 367 | * Create TLS Secrets within Kubernetes, and use them in your ingress controller. 368 | * Managing RBAC (Don't know enough about this one, but sounds like a good concept to include) 369 | * Creating new roles, etc 370 | 371 | I'll have a think and if anymore come to me, I'll let you know. 372 | 373 | 374 | Denny Zhang (Github . Blogger) 375 | [1:19 AM] 376 | :thumbsup: 377 | 378 | Will update per your suggestions tomorrow, Aaron 379 | ** TODO k8s add DNS challenges 380 | Gui [4:01 PM] 381 | Getting familiar with the concepts like pod, service, RC, deployment, etc. 382 | 383 | 384 | [4:02] 385 | Try volume 386 | 387 | 388 | [4:02] 389 | DNS. 390 | 391 | 392 | Denny Zhang (Github . Blogger) 393 | [4:02 PM] 394 | I'm trying to cover the volume via mysql scenarios 395 | 396 | 397 | Gui [4:02 PM] 398 | And other addons 399 | 1 reply Today at 4:03 PM View thread 400 | 401 | 402 | Denny Zhang (Github . Blogger) 403 | [4:02 PM] 404 | For DNS, not sure whether I get your point 405 | 406 | 407 | Gui [4:03 PM] 408 | I haven't tried a lot myself. 409 | 1 reply Today at 4:03 PM View thread 410 | 411 | 412 | [4:03] 413 | Like every pod and service has an DNS name to talk to each other. 414 | 415 | 416 | Denny Zhang (Github . Blogger) [4:04 PM] 417 | Yes, that makes sense 418 | 419 | 420 | [4:04] 421 | For addons, do you have any recommended scenario? 422 | ** TODO k8s add challenge of addon 423 | https://www.cncf.io 424 | 425 | https://kubernetes.io/docs/concepts/cluster-administration/addons/ 426 | ** TODO k8s networking models 427 | ** TODO k8s example: https://github.com/kubernetes/examples 428 | ** TODO Blog: Wordpress powered by k8s, docker swarm 429 | ** # --8<-------------------------- separator ------------------------>8-- :noexport: 430 | ** TODO [#A] absord: https://github.com/kubecamp/kubernetes_in_one_day 431 | ** TODO [#A] absord: https://github.com/kubecamp/kubernetes_in_2_days 432 | ** DONE kubectl config view 433 | CLOSED: [2017-12-31 Sun 10:40] 434 | ** DONE [#A] kubernetes persistent volume claim pending 435 | CLOSED: [2017-12-31 Sun 11:32] 436 | https://github.com/openshift/origin/issues/7170 437 | 438 | kubectl get pvc 439 | kubectl get pv 440 | 441 | #+BEGIN_EXAMPLE 442 | ubuntu@k8s1:~$ kubectl describe pvc 443 | Name: ironic-gerbil-jenkins 444 | Namespace: default 445 | StorageClass: 446 | Status: Pending 447 | Volume: 448 | Labels: app=ironic-gerbil-jenkins 449 | chart=jenkins-0.10.2 450 | heritage=Tiller 451 | release=ironic-gerbil 452 | Annotations: 453 | Capacity: 454 | Access Modes: 455 | Events: 456 | Type Reason Age From Message 457 | ---- ------ ---- ---- ------- 458 | Normal FailedBinding 37s (x261 over 2h) persistentvolume-controller no persistent volumes available for this claim and no storage class is set 459 | 460 | 461 | Name: my-mysql-mysql 462 | Namespace: default 463 | StorageClass: 464 | Status: Pending 465 | Volume: 466 | Labels: app=my-mysql-mysql 467 | chart=mysql-0.3.2 468 | heritage=Tiller 469 | release=my-mysql 470 | Annotations: 471 | Capacity: 472 | Access Modes: 473 | Events: 474 | Type Reason Age From Message 475 | ---- ------ ---- ---- ------- 476 | Normal FailedBinding 7s (x5 over 1m) persistentvolume-controller no persistent volumes available for this claim and no storage class is set 477 | #+END_EXAMPLE 478 | ** DONE kubernetes start a container for testing: kubectl run -i --tty ubuntu --image=ubuntu:16.04 --restart=Never -- bash -il 479 | CLOSED: [2017-12-31 Sun 11:26] 480 | ** DONE [#A] ReplicaSet is the next-generation Replication Controller. 481 | CLOSED: [2017-12-04 Mon 11:26] 482 | The only difference between a ReplicaSet and a Replication Controller right now is the selector support. 483 | 484 | https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/ 485 | 486 | https://github.com/arun-gupta/oreilly-kubernetes-book/blob/master/ch01/wildfly-replicaset.yml 487 | Next generation Replication Controller 488 | 489 | Set-based selector requirement 490 | - Expression: key, operator, value 491 | - Operators: In, NotIn, Exists, DoesNotExist 492 | 493 | ▪Generally created with Deployment 494 | ▪Enables Horizontal Pod Autoscaling 495 | ** DONE k8s yaml API version: https://kubernetes.io/docs/reference/federation/extensions/v1beta1/definitions/ 496 | CLOSED: [2017-12-03 Sun 12:50] 497 | ** DONE k8s cronjob 498 | CLOSED: [2018-01-03 Wed 12:26] 499 | https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/ 500 | 501 | kubectl create -f ./cronjob.yaml 502 | kubectl get cronjob hello 503 | kubectl get jobs --watch 504 | kubectl delete cronjob hello 505 | 506 | #+BEGIN_EXAMPLE 507 | apiVersion: batch/v1beta1 508 | kind: CronJob 509 | metadata: 510 | name: hello 511 | spec: 512 | schedule: "*/1 * * * *" 513 | jobTemplate: 514 | spec: 515 | template: 516 | spec: 517 | containers: 518 | - name: hello 519 | image: busybox 520 | args: 521 | - /bin/sh 522 | - -c 523 | - date; echo Hello from the Kubernetes cluster 524 | restartPolicy: OnFailure 525 | #+END_EXAMPLE 526 | ** DONE [#B] check k8s status: kubectl get cs 527 | CLOSED: [2018-01-03 Wed 11:57] 528 | ** BYPASS crictl not found in system path: warning 529 | CLOSED: [2018-01-03 Wed 12:36] 530 | ** DONE kubernetes default service type: ClusterIP 531 | CLOSED: [2018-01-02 Tue 11:07] 532 | ** DONE kubectl get nodes: Unable to connect to the server: x509: certificate signed by unknown authority: incorrect /etc/kubernetes/admin.conf 533 | CLOSED: [2018-01-04 Thu 00:09] 534 | 535 | 536 | root@k8s1:~# kubectl get nodes 537 | Unable to connect to the server: x509: certificate signed by unknown authority (possibly because of "crypto/rsa: verification error" while trying to verify candidate authority certificate "kubernetes") 538 | root@k8s1:~# echo $KUBECONFIG 539 | 540 | root@k8s1:~# export KUBECONFIG=/etc/kubernetes/admin.conf 541 | root@k8s1:~# kubectl get nodes 542 | NAME STATUS ROLES AGE VERSION 543 | k8s1 Ready master 29m v1.9.0 544 | k8s2 NotReady 17m v1.9.0 545 | ** DONE [#A] kubernetes-the-hard-way: https://github.com/kelseyhightower/kubernetes-the-hard-way 546 | CLOSED: [2017-12-04 Mon 15:49] 547 | *** CANCELED k8s hardway: etcdctl: Error: context deadline exceeded 548 | CLOSED: [2017-12-04 Mon 17:54] 549 | https://github.com/kelseyhightower/kubernetes-the-hard-way/blob/e8d728d0162ebcdf951464caa8be3a5b156eb463/docs/07-bootstrapping -etcd.md 550 | #+BEGIN_EXAMPLE 551 | mac@controller-0:~$ ETCDCTL_API=3 etcdctl member list 552 | Error: context deadline exceeded 553 | #+END_EXAMPLE 554 | 555 | #+BEGIN_EXAMPLE 556 | mac@controller-0:~$ kubectl get componentstatuses 557 | NAME STATUS MESSAGE ERROR 558 | etcd-2 Unhealthy Get https://10.240.0.12:2379/health: dial tcp 10.240.0.12:2379: getsockopt: connection refused 559 | controller-manager Healthy ok 560 | etcd-1 Unhealthy Get https://10.240.0.11:2379/health: dial tcp 10.240.0.11:2379: getsockopt: connection refused 561 | scheduler Healthy ok 562 | etcd-0 Unhealthy Get https://10.240.0.10:2379/health: net/http: TLS handshake timeout 563 | #+END_EXAMPLE 564 | ** DONE k8s livenessProbe(when to restart a Container), readinessProbe(when is ready to accept requests) 565 | CLOSED: [2018-01-08 Mon 07:41] 566 | https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/ 567 | http://kubernetesbyexample.com/healthz/ 568 | https://kubernetes-v1-4.github.io/docs/user-guide/liveness/ 569 | https://github.com/arun-gupta/kubernetes-java-sample/blob/master/wildfly-pod-hc-http.yaml 570 | http://kubernetesbyexample.com/healthz/ 571 | 572 | Probes have a number of fields that you can use to more precisely control the behavior of liveness and readiness checks: 573 | 574 | initialDelaySeconds: Number of seconds after the container has started before liveness or readiness probes are initiated. 575 | periodSeconds: How often (in seconds) to perform the probe. Default to 10 seconds. Minimum value is 1. 576 | timeoutSeconds: Number of seconds after which the probe times out. Defaults to 1 second. Minimum value is 1. 577 | successThreshold: Minimum consecutive successes for the probe to be considered successful after having failed. Defaults to 1. Must be 1 for liveness. Minimum value is 1. 578 | failureThreshold: When a Pod starts and the probe fails, Kubernetes will try failureThreshold times before giving up. Giving up in case of liveness probe means restarting the Pod. In case of readiness probe the Pod will be marked Unready. Defaults to 3. Minimum value is 1. 579 | 580 | #+BEGIN_EXAMPLE 581 | apiVersion: v1 582 | kind: Pod 583 | metadata: 584 | labels: 585 | test: liveness 586 | name: liveness-exec 587 | spec: 588 | containers: 589 | - args: 590 | - /bin/sh 591 | - -c 592 | - echo ok > /tmp/health; sleep 10; rm -rf /tmp/health; sleep 600 593 | image: gcr.io/google_containers/busybox 594 | livenessProbe: 595 | exec: 596 | command: 597 | - cat 598 | - /tmp/health 599 | initialDelaySeconds: 15 600 | timeoutSeconds: 1 601 | name: liveness 602 | #+END_EXAMPLE 603 | ** DONE list all critical pods 604 | CLOSED: [2018-01-04 Thu 10:10] 605 | kubectl --namespace kube-system get pods 606 | 607 | for pod in $(kubectl --namespace kube-system get pods -o jsonpath="{.items[*].metadata.name}"); do 608 | node_info=$(kubectl --namespace kube-system describe pod $pod | grep "Node:") 609 | echo "Pod: $pod, $node_info" 610 | done 611 | ** DONE k8s cheatsheet: kube-shell https://github.com/cloudnativelabs/kube-shell 612 | CLOSED: [2017-12-31 Sun 10:47] 613 | ** DONE k8s configmap 614 | CLOSED: [2018-01-08 Mon 10:32] 615 | https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/ 616 | | Name | Summary | 617 | |-----------------------------------------------------+---------| 618 | | kubectl get configmaps my-wordpress-mariadb -o yaml | | 619 | ** DONE [#A] k8s initContainers debug: kubectl logs -c 620 | CLOSED: [2018-01-05 Fri 16:29] 621 | https://kubernetes.io/docs/tasks/debug-application-cluster/debug-init-containers/ 622 | ** DONE Use GCE to setup k8s cluster deployment 623 | CLOSED: [2018-01-07 Sun 07:26] 624 | https://github.com/kelseyhightower/kubernetes-the-hard-way 625 | 626 | https://cloud.google.com/ 627 | source /Users/mac/Downloads/google-cloud-sdk/completion.bash.inc 628 | source /Users/mac/Downloads/google-cloud-sdk/path.bash.inc 629 | *** doc: gcloud setup 630 | #+BEGIN_EXAMPLE 631 | [28] us-central1-f 632 | [29] us-central1-c 633 | [30] us-central1-b 634 | [31] us-east1-d 635 | [32] us-east1-c 636 | [33] us-east1-b 637 | [34] us-east4-c 638 | [35] us-east4-a 639 | [36] us-east4-b 640 | [37] us-west1-a 641 | [38] us-west1-c 642 | [39] us-west1-b 643 | [40] Do not set default zone 644 | Please enter numeric choice or text value (must exactly match list 645 | item): 36 646 | 647 | Your project default Compute Engine zone has been set to [us-east4-b]. 648 | You can change it by running [gcloud config set compute/zone NAME]. 649 | 650 | Your project default Compute Engine region has been set to [us-east4]. 651 | You can change it by running [gcloud config set compute/region NAME]. 652 | 653 | Created a default .boto configuration file at [/Users/mac/.boto]. See this file and 654 | [https://cloud.google.com/storage/docs/gsutil/commands/config] for more 655 | information about configuring Google Cloud Storage. 656 | Your Google Cloud SDK is configured and ready to use! 657 | 658 | * Commands that require authentication will use denny.zhang001@gmail.com by default 659 | * Commands will reference project `denny-k8s-test1` by default 660 | * Compute Engine commands will use region `us-east4` by default 661 | * Compute Engine commands will use zone `us-east4-b` by default 662 | 663 | Run `gcloud help config` to learn how to change individual settings 664 | 665 | This gcloud configuration is called [default]. You can create additional configurations if you work with multiple accounts and/or projects. 666 | Run `gcloud topic configurations` to learn more. 667 | 668 | Some things to try next: 669 | 670 | * Run `gcloud --help` to see the Cloud Platform services you can interact with. And run `gcloud help COMMAND` to get help on any gcloud command. 671 | * Run `gcloud topic -h` to learn about advanced features of the SDK like arg files and output formatting 672 | #+END_EXAMPLE 673 | *** TODO [#A] can't find gcloud :IMPORTANT: 674 | source /Users/mac/Downloads/google-cloud-sdk/completion.bash.inc 675 | source /Users/mac/Downloads/google-cloud-sdk/path.bash.inc 676 | ** DONE kubectl get pod 677 | CLOSED: [2018-04-28 Sat 09:28] 678 | /etc/kubernetes/admin.conf /etc/kubernetes/kubelet.conf /etc/kubernetes/bootstrap-kubelet.conf /etc/kubernetes/controller-manager.conf /etc/kubernetes/scheduler.conf] 679 | 680 | #+BEGIN_EXAMPLE 681 | Your Kubernetes master has initialized successfully! 682 | 683 | To start using your cluster, you need to run the following as a regular user: 684 | 685 | mkdir -p $HOME/.kube 686 | sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config 687 | sudo chown $(id -u):$(id -g) $HOME/.kube/config 688 | 689 | You should now deploy a pod network to the cluster. 690 | Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: 691 | https://kubernetes.io/docs/concepts/cluster-administration/addons/ 692 | #+END_EXAMPLE 693 | ** DONE pod CrashLoopBackOff: starting, then crashing, then starting again and crashing again. 694 | 695 | CLOSED: [2018-01-05 Fri 15:47] 696 | https://www.krenger.ch/blog/crashloopbackoff-and-how-to-fix-it/ 697 | 698 | https://kubernetes.io/docs/tasks/debug-application-cluster/debug-init-containers/ 699 | 700 | | Status | Meaning | 701 | |----------------------------+-------------------------------------------------------------| 702 | | Init:N/M | The Pod has M Init Containers, and N have completed so far. | 703 | | Init:Error | An Init Container has failed to execute. | 704 | | Init:CrashLoopBackOff | An Init Container has failed repeatedly. | 705 | | Pending | The Pod has not yet begun executing Init Containers. | 706 | | PodInitializing or Running | The Pod has already finished executing Init Containers. | 707 | ** DONE k8s ImagePullBackOff: describe pod $pod_name; No space 708 | CLOSED: [2018-06-25 Mon 14:28] 709 | ** DONE default pods for single node installation 710 | CLOSED: [2018-04-28 Sat 08:49] 711 | #+BEGIN_EXAMPLE 712 | root@mdm-k8s-node2:~# docker ps 713 | CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 714 | 75d08dd2b171 k8s.gcr.io/kube-proxy-amd64@sha256:c7036a8796fd20c16cb3b1cef803a8e980598bff499084c29f3c759bdb429cd2 "/usr/local/bin/ku..." 16 hours ago Up 16 hours k8s_kube-proxy_kube-proxy-jmcs9_kube-system_02a0eac8-4a75-11e8-afce-7aa5a78d07bd_0 715 | 0a769558ec4f k8s.gcr.io/pause-amd64:3.1 "/pause" 16 hours ago Up 16 hours k8s_POD_kube-proxy-jmcs9_kube-system_02a0eac8-4a75-11e8-afce-7aa5a78d07bd_0 716 | 2af1fbfd581a k8s.gcr.io/kube-apiserver-amd64@sha256:1ba863c8e9b9edc6d1329ebf966e4aa308ca31b42a937b4430caf65aa11bdd12 "kube-apiserver --..." 16 hours ago Up 16 hours k8s_kube-apiserver_kube-apiserver-mdm-k8s-node2_kube-system_fee65b809c1e455cf1672ebe7efc4bc7_0 717 | 63c214ac8d1b k8s.gcr.io/kube-controller-manager-amd64@sha256:922ac89166ea228cdeff43e4c445a5dc4204972cc0e265a8762beec07b6238bf "kube-controller-m..." 16 hours ago Up 16 hours k8s_kube-controller-manager_kube-controller-manager-mdm-k8s-node2_kube-system_5ad7a10c5a8589117db7258c7d499a33_0 718 | 324ff1a8d357 k8s.gcr.io/kube-scheduler-amd64@sha256:5f50a339f66037f44223e2b4607a24888177da6203a7bc6c8554e0f09bd2b644 "kube-scheduler --..." 16 hours ago Up 16 hours k8s_kube-scheduler_kube-scheduler-mdm-k8s-node2_kube-system_aa8d5cab3ea096315de0c2003230d4f9_0 719 | dce77d944669 k8s.gcr.io/etcd-amd64@sha256:68235934469f3bc58917bcf7018bf0d3b72129e6303b0bef28186d96b2259317 "etcd --listen-cli..." 16 hours ago Up 16 hours k8s_etcd_etcd-mdm-k8s-node2_kube-system_59f847fe34319ab1263f0b3ee03df8a3_0 720 | 2af621e52e11 k8s.gcr.io/pause-amd64:3.1 "/pause" 16 hours ago Up 16 hours k8s_POD_kube-apiserver-mdm-k8s-node2_kube-system_fee65b809c1e455cf1672ebe7efc4bc7_0 721 | bdc64588b27d k8s.gcr.io/pause-amd64:3.1 "/pause" 16 hours ago Up 16 hours k8s_POD_kube-controller-manager-mdm-k8s-node2_kube-system_5ad7a10c5a8589117db7258c7d499a33_0 722 | 14dd26427abf k8s.gcr.io/pause-amd64:3.1 "/pause" 16 hours ago Up 16 hours k8s_POD_kube-scheduler-mdm-k8s-node2_kube-system_aa8d5cab3ea096315de0c2003230d4f9_0 723 | 17bfbb8af205 k8s.gcr.io/pause-amd64:3.1 "/pause" 16 hours ago Up 16 hours k8s_POD_etcd-mdm-k8s-node2_kube-system_59f847fe34319ab1263f0b3ee03df8a3_0 724 | #+END_EXAMPLE 725 | ** DONE One pod may have multiple containers 726 | CLOSED: [2018-06-19 Tue 14:31] 727 | If a pod has more than 1 containers then you need to provide the name of the specific container. 728 | ** DONE kubectl edit deployment parameters 729 | CLOSED: [2018-04-15 Sun 21:49] 730 | https://github.com/kubernetes/helm/issues/2464 731 | kubectl -n kube-system patch deployment tiller-deploy -p '{"spec": {"template": {"spec": {"automountServiceAccountToken": true}}}}' 732 | 733 | kubectl --namespace=kube-system edit deployment/tiller-deploy and changed automountServiceAccountToken to true. 734 | ** DONE [#A] k8s sidecar 735 | CLOSED: [2018-07-15 Sun 22:50] 736 | https://k8s.io/examples/admin/logging/two-files-counter-pod-streaming-sidecar.yaml 737 | #+BEGIN_EXAMPLE 738 | apiVersion: v1 739 | kind: Pod 740 | metadata: 741 | name: counter 742 | spec: 743 | containers: 744 | - name: count 745 | image: busybox 746 | args: 747 | - /bin/sh 748 | - -c 749 | - > 750 | i=0; 751 | while true; 752 | do 753 | echo "$i: $(date)" >> /var/log/1.log; 754 | echo "$(date) INFO $i" >> /var/log/2.log; 755 | i=$((i+1)); 756 | sleep 1; 757 | done 758 | volumeMounts: 759 | - name: varlog 760 | mountPath: /var/log 761 | - name: count-log-1 762 | image: busybox 763 | args: [/bin/sh, -c, 'tail -n+1 -f /var/log/1.log'] 764 | volumeMounts: 765 | - name: varlog 766 | mountPath: /var/log 767 | - name: count-log-2 768 | image: busybox 769 | args: [/bin/sh, -c, 'tail -n+1 -f /var/log/2.log'] 770 | volumeMounts: 771 | - name: varlog 772 | mountPath: /var/log 773 | volumes: 774 | - name: varlog 775 | emptyDir: {} 776 | #+END_EXAMPLE 777 | ** TODO [#A] k8s debug why termination takes time 778 | ** TODO Kubernetes availability 779 | *** TODO Building High-Availability Clusters: https://kubernetes.io/docs/admin/high-availability/ 780 | ** TODO [#A] Blog: Kubernetes Service Type: NodePort, ClusterIP and Loadbalancer? 781 | #+BEGIN_EXAMPLE 782 | https://kubernetes.io/docs/concepts/services-networking/service/ 783 | 784 | Publishing services - service types 785 | For some parts of your application (e.g. frontends) you may want to expose a Service onto an external (outside of your cluster) IP address. 786 | 787 | Kubernetes ServiceTypes allow you to specify what kind of service you want. The default is ClusterIP. 788 | 789 | Type values and their behaviors are: 790 | 791 | ClusterIP: Exposes the service on a cluster-internal IP. Choosing this value makes the service only reachable from within the cluster. This is the default ServiceType. 792 | NodePort: Exposes the service on each Node's IP at a static port (the NodePort). A ClusterIP service, to which the NodePort service will route, is automatically created. You'll be able to contact the NodePort service, from outside the cluster, by requesting :. 793 | LoadBalancer: Exposes the service externally using a cloud provider's load balancer. NodePort and ClusterIP services, to which the external load balancer will route, are automatically created. 794 | ExternalName: Maps the service to the contents of the externalName field (e.g. foo.bar.example.com), by returning a CNAME record with its value. No proxying of any kind is set up. This requires version 1.7 or higher of kube-dns. 795 | #+END_EXAMPLE 796 | *** Type: Loadbalancer 797 | *** Type: ClusterIP 798 | *** Type: NodePort 799 | If you set the type field to "NodePort", the Kubernetes master will allocate a port from a flag-configured range (default: 30000-32767) 800 | *** # --8<-------------------------- separator ------------------------>8-- :noexport: 801 | *** TODO Now if i access IP:NodePort, will it balance the load across multiple pods ? 802 | https://kubernetes.io/docs/tasks/access-application-cluster/load-balance-access-application-cluster/ 803 | #+BEGIN_EXAMPLE 804 | Vivek Yadav [8:34 AM] 805 | Hey Denny, quick question - 806 | 807 | ``` 808 | --- 809 | apiVersion: v1 810 | kind: Service 811 | metadata: 812 | name: span 813 | labels: 814 | app: span 815 | spec: 816 | type: NodePort 817 | ports: 818 | - port: 80 819 | nodePort: 30080 820 | selector: 821 | app: spa 822 | 823 | --- 824 | apiVersion: apps/v1beta2 825 | kind: Deployment 826 | metadata: 827 | name: spa 828 | spec: 829 | replicas: 2 830 | selector: 831 | matchLabels: 832 | app: spa 833 | template: 834 | metadata: 835 | labels: 836 | app: spa 837 | spec: 838 | containers: 839 | - name: py 840 | image: viveky4d4v/local-simple-python:latest 841 | ports: 842 | - containerPort: 8080 843 | - name: nginx 844 | image: viveky4d4v/local-nginx-lb:latest 845 | ports: 846 | - containerPort: 80 847 | imagePullSecrets: 848 | - name: regsecret 849 | 850 | ``` 851 | 852 | 853 | Now if i access IP:NodePort, will it balance the load across multiple pods ? 854 | 855 | 856 | Denny Zhang (Github . Blogger) [8:35 AM] 857 | I don't think so 858 | #+END_EXAMPLE 859 | *** TODO How Does NodePort work behind the scene? 860 | *** # --8<-------------------------- separator ------------------------>8-- :noexport: 861 | *** TODO How Loadbalancer is implemented in code? 862 | *** # --8<-------------------------- separator ------------------------>8-- :noexport: 863 | *** TODO Does Loadbalancer works only for public cloud? 864 | *** TODO How I configure Ingress? 865 | ** TODO [#A] NodePort VS clusterIP :IMPORTANT: 866 | https://stackoverflow.com/questions/41509439/whats-the-difference-between-clusterip-nodeport-and-loadbalancer-service-types 867 | http://weezer.su/kubernetes-1.html 868 | https://docs.openshift.com/container-platform/3.3/dev_guide/getting_traffic_into_cluster.html 869 | 870 | clusterIP: You can only access this service while inside the cluster. 871 | ** TODO [#A] k8s feature watch list 872 | *** I want to check pod initContainer logs, but I don't want to specify initContainer by name 873 | #+BEGIN_EXAMPLE 874 | macs-MacBook-Pro:Scenario-401 mac$ kubectl logs my-jenkins-jenkins-89889ddb7-ct7jw -c 1 875 | Error from server (BadRequest): container 1 is not valid for pod my-jenkins-jenkins-89889ddb7-ct7jw 876 | macs-MacBook-Pro:Scenario-401 mac$ kubectl logs my-jenkins-jenkins-89889ddb7-ct7jw -c copy-default-config 877 | Error from server (BadRequest): container "copy-default-config" in pod "my-jenkins-jenkins-89889ddb7-ct7jw" is waiting to start: PodInitializing 878 | macs-MacBook-Pro:Scenario-401 mac$ kubectl logs my-jenkins-jenkins-89889ddb7-ct7jw -c copy-default-config 879 | Error from server (BadRequest): container "copy-default-config" in pod "my-jenkins-jenkins-89889ddb7-ct7jw" is waiting to start: PodInitializing 880 | #+END_EXAMPLE 881 | *** Support using environment variables inside deployment yaml file 882 | https://github.com/kubernetes/kubernetes/issues/52787 883 | ** TODO pod error: CreateContainerConfigError 884 | https://github.com/kubernetes/minikube/issues/2256 885 | #+BEGIN_EXAMPLE 886 | bash-3.2$ kubectl get pod my-wordpress-wordpress-df987548d-btvf5 887 | NAME READY STATUS RESTARTS AGE 888 | my-wordpress-wordpress-df987548d-btvf5 0/1 CreateContainerConfigError 0 2m 889 | bash-3.2$ 890 | #+END_EXAMPLE 891 | 892 | #+BEGIN_EXAMPLE 893 | bash-3.2$ kubectl describe pod/my-wordpress-wordpress-df987548d-btvf5 894 | Name: my-wordpress-wordpress-df987548d-btvf5 895 | Namespace: default 896 | Node: minikube/192.168.99.102 897 | Start Time: Fri, 05 Jan 2018 16:41:27 -0600 898 | Labels: app=my-wordpress-wordpress 899 | pod-template-hash=895431048 900 | Annotations: kubernetes.io/created-by={"kind":"SerializedReference","apiVersion":"v1","reference":{"kind":"ReplicaSet","namespace":"default","name":"my-wordpress-wordpress-df987548d","uid":"910e01e0-f269-11e7-b6d8... 901 | Status: Pending 902 | IP: 172.17.0.6 903 | Created By: ReplicaSet/my-wordpress-wordpress-df987548d 904 | Controlled By: ReplicaSet/my-wordpress-wordpress-df987548d 905 | Containers: 906 | my-wordpress-wordpress: 907 | Container ID: 908 | Image: bitnami/wordpress:4.9.1-r1 909 | Image ID: 910 | Ports: 80/TCP, 443/TCP 911 | State: Waiting 912 | Reason: CreateContainerConfigError 913 | Ready: False 914 | Restart Count: 0 915 | Requests: 916 | cpu: 300m 917 | memory: 512Mi 918 | Liveness: http-get http://:http/wp-login.php delay=120s timeout=5s period=10s #success=1 #failure=6 919 | Readiness: http-get http://:http/wp-login.php delay=30s timeout=3s period=5s #success=1 #failure=3 920 | Environment: 921 | ALLOW_EMPTY_PASSWORD: yes 922 | MARIADB_ROOT_PASSWORD: Optional: false 923 | MARIADB_HOST: my-wordpress-mariadb 924 | MARIADB_PORT_NUMBER: 3306 925 | WORDPRESS_DATABASE_NAME: bitnami_wordpress 926 | WORDPRESS_DATABASE_USER: bn_wordpress 927 | WORDPRESS_DATABASE_PASSWORD: Optional: false 928 | WORDPRESS_USERNAME: admin 929 | WORDPRESS_PASSWORD: Optional: false 930 | WORDPRESS_EMAIL: contact@dennyzhang.com 931 | WORDPRESS_FIRST_NAME: FirstName 932 | WORDPRESS_LAST_NAME: LastName 933 | WORDPRESS_BLOG_NAME: My DevOps Blog! 934 | SMTP_HOST: 935 | SMTP_PORT: 936 | SMTP_USER: 937 | SMTP_PASSWORD: Optional: false 938 | SMTP_USERNAME: 939 | SMTP_PROTOCOL: 940 | Mounts: 941 | /bitnami/apache from wordpress-data (rw) 942 | /bitnami/php from wordpress-data (rw) 943 | /bitnami/wordpress from wordpress-data (rw) 944 | /var/run/secrets/kubernetes.io/serviceaccount from default-token-tc8kd (ro) 945 | Conditions: 946 | Type Status 947 | Initialized True 948 | Ready False 949 | PodScheduled True 950 | Volumes: 951 | wordpress-data: 952 | Type: PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace) 953 | ClaimName: my-wordpress-wordpress 954 | ReadOnly: false 955 | default-token-tc8kd: 956 | Type: Secret (a volume populated by a Secret) 957 | SecretName: default-token-tc8kd 958 | Optional: false 959 | QoS Class: Burstable 960 | Node-Selectors: 961 | Tolerations: 962 | Events: 963 | Type Reason Age From Message 964 | ---- ------ ---- ---- ------- 965 | Normal Scheduled 1m default-scheduler Successfully assigned my-wordpress-wordpress-df987548d-btvf5 to minikube 966 | Normal SuccessfulMountVolume 1m kubelet, minikube MountVolume.SetUp succeeded for volume "pvc-910644d3-f269-11e7-b6d8-08002782d6cd" 967 | Normal SuccessfulMountVolume 1m kubelet, minikube MountVolume.SetUp succeeded for volume "default-token-tc8kd" 968 | Normal Pulled 1s (x7 over 1m) kubelet, minikube Container image "bitnami/wordpress:4.9.1-r1" already present on machine 969 | Warning Failed 1s (x7 over 1m) kubelet, minikube Error: lstat /tmp/hostpath-provisioner/pvc-910644d3-f269-11e7-b6d8-08002782d6cd: no such file or directory 970 | Warning FailedSync 1s (x7 over 1m) kubelet, minikube Error syncing pod 971 | bash-3.2$ 972 | #+END_EXAMPLE 973 | ** TODO [#A] Certified Kubernetes Administrator (CKA) :IMPORTANT: 974 | https://www.cncf.io/certification/expert/ 975 | 976 | https://github.com/cncf/curriculum/blob/master/certified_kubernetes_administrator_exam_v1.8.0.pdf 977 | 978 | It is an online, proctored, performance-based test that requires solving multiple issues from a command line. 979 | 980 | Candidates have 3 hours to complete the tasks. 981 | ** HALF Difference in between selectors and labels 982 | ** TODO [#A] kubernetes mount a file to pod :IMPORTANT: 983 | https://stackoverflow.com/questions/33415913/whats-the-best-way-to-share-mount-one-file-into-a-pod 984 | https://www.linkedin.com/feed/update/urn:li:activity:6355445509146107904/ 985 | ** TODO K8S label & Selector 986 | https://github.com/dennyzhang/dennytest/tree/master/cheatsheet-kubernetes-A4][challenges-leetcode-interesting]] 987 | * [#A] k8s metric server :noexport:IMPORTANT: 988 | Metrics Server is a cluster-wide aggregator of resource usage data. 989 | 990 | Metrics Server registered in the main API server through Kubernetes aggregator. 991 | 992 | https://github.com/kubernetes-incubator/metrics-server 993 | https://github.com/kubernetes-incubator/metrics-server/tree/master/deploy/1.8%2B 994 | 995 | https://kubernetes.io/docs/tasks/debug-application-cluster/core-metrics-pipeline/ 996 | | Name | Summary | 997 | |----------------+-------------------------------------------------------------------| 998 | | Core metrics | node/container level metrics; CPU, memory, disk and network, etc. | 999 | | Custom metrics | refers to application metrics, e.g. HTTP request rate. | 1000 | 1001 | Today (Kubernetes 1.7), there are several sources of metrics within a Kubernetes cluster 1002 | | Name | Summary | 1003 | |----------------+---------------------------------------------------------------------| 1004 | | Heapster | k8s add-on | 1005 | | Cadvisor | a standalone container/node metrics collection and monitoring tool. | 1006 | | Kubernetes API | does not track metrics. But can get real time metrics | 1007 | ** metric server 1008 | Resource Metrics API is an effort to provide a first-class Kubernetes API (stable, versioned, discoverable, available through apiserver and with client support) that serves resource usage metrics for pods and nodes. 1009 | 1010 | - metric server is sort of a stripped-down version of Heapster 1011 | - The metrics-server will collect "Core" metrics from cAdvisor APIs (currently embedded in the kubelet) and store them in memory as opposed to in etcd. 1012 | - The metrics-server will provide a supported API for feeding schedulers and horizontal pod auto-scalers 1013 | - All other Kubernetes components will supply their own metrics in a Prometheus format 1014 | ** Cadvisor 1015 | Cadvisor monitors node and container core metrics in addition to container events. 1016 | It natively provides a Prometheus metrics endpoint 1017 | The Kubernetes kublet has an embedded Cadvisor that only exposes the metrics, not the events. 1018 | ** heapster 1019 | Heapster is an add on to Kubernetes that collects and forwards both node, namespace, pod and container level metrics to one or more "sinks" (e.g. InfluxDB). 1020 | 1021 | It also provides REST endpoints to gather those metrics. The metrics are constrained to CPU, filesystem, memory, network and uptime. 1022 | 1023 | Heapster queries the kubelet for its data. 1024 | 1025 | Today, heapster is the source of the time-series data for the Kubernetes Dashboard. 1026 | ** # --8<-------------------------- separator ------------------------>8-- :noexport: 1027 | ** TODO How to query metric server 1028 | ** TODO Key scenarios of metric server 1029 | The metrics-server will provide a much needed official API for the internal components of Kubernetes to make decisions about the utilization and performance of the cluster. 1030 | 1031 | - HPA(Horizontal Pod Autoscaler) need input to do good auto-scaling 1032 | ** TODO There are plans for an "Infrastore", a Kubernetes component that keeps historical data and events 1033 | ** # --8<-------------------------- separator ------------------------>8-- :noexport: 1034 | ** TODO why from heapster to k8s metric server? 1035 | ** TODO kube-aggregator 1036 | ** TODO what is prometheus format? 1037 | #+BEGIN_EXAMPLE 1038 | Denny Zhang [12:34 AM] 1039 | An easy introduction about k8s metric server. (It will replace heapster) 1040 | 1041 | https://blog.freshtracks.io/what-is-the-the-new-kubernetes-metrics-server-849c16aa01f4 1042 | 1043 | > All other Kubernetes components will supply their own metrics in a Prometheus format 1044 | 1045 | In logging domain, we can say `syslog` is the standard format 1046 | 1047 | In metric domain, maybe we can choose `prometheus` as the standard format. 1048 | #+END_EXAMPLE 1049 | ** Metrics Use Cases 1050 | https://github.com/kubernetes/community/blob/master/contributors/design-proposals/instrumentation/resource-metrics-api.md 1051 | 1052 | https://docs.giantswarm.io/guides/kubernetes-heapster/ 1053 | 1054 | #+BEGIN_EXAMPLE 1055 | Horizontal Pod Autoscaler: It scales pods automatically based on CPU or custom metrics (not explained here). More information here. 1056 | Kubectl top: The command top of our beloved Kubernetes CLI display metrics directly in the terminal. 1057 | Kubernetes dashboard: See Pod and Nodes metrics integrated into the main Kubernetes UI dashboard. More info here 1058 | Scheduler: In the future Core Metrics will be considered in order to schedule best-effort Pods. 1059 | #+END_EXAMPLE 1060 | ** useful link 1061 | https://blog.freshtracks.io/what-is-the-the-new-kubernetes-metrics-server-849c16aa01f4 1062 | https://blog.outlyer.com/monitoring-kubernetes-with-heapster-and-prometheus 1063 | https://www.outcoldman.com/en/archive/2017/07/09/kubernetes-monitoring-resources/ 1064 | * k8s loadbalancer :noexport: 1065 | ** DONE k8s service: loadbalancer 1066 | CLOSED: [2018-06-19 Tue 13:51] 1067 | #+BEGIN_EXAMPLE 1068 | cat > service.yml < user.yaml <8-- :noexport: 1284 | * DONE Why we need Static Pods :noexport: 1285 | CLOSED: [2019-01-04 Fri 15:04] 1286 | https://kubernetes.io/docs/tasks/administer-cluster/static-pod/ 1287 | Denny Zhang [2:26 PM] 1288 | Fan, ever heard of `Static Pods` in k8s? 1289 | 1290 | If yes, could you give me two use scenarios why I would use it. 1291 | 1292 | Fan Zhang [3:00 PM] 1293 | 我听说过 1294 | 其实就是kubelet直接管理的pod 1295 | 1296 | Denny Zhang [3:01 PM] 1297 | 是的,文档是这么说的. 1298 | 1299 | Fan Zhang [3:01 PM] 1300 | 我觉得这个是DeamonSet的补充 1301 | 1302 | Denny Zhang [3:01 PM] 1303 | 我在尝试理解这个背后的应用场景 1304 | 1305 | Fan Zhang [3:02 PM] 1306 | 因为有时候在node上需要有一些particular的service,但又不希望被kubernetes的schecular 管理 1307 | 1308 | Denny Zhang [3:02 PM] 1309 | 将OS的进程容器化 1310 | 但这些只是OS级别,而不是k8s系统或app应用级别的进程 1311 | 可以这样理解吗？ 1312 | 1313 | Fan Zhang [3:03 PM] 1314 | 否则 drain之后就没有了 1315 | 可以这样理解 1316 | 1317 | Denny Zhang [3:04 PM] 1318 | 所以drain node不会把static pod删掉？ 1319 | * TODO Why need kubernetes/apiserver: https://github.com/kubernetes/apiserver :noexport: 1320 | Library for writing a Kubernetes-style API server. 1321 | 1322 | https://github.com/kubernetes/kube-aggregator 1323 | * TODO [#A] Questions :noexport: 1324 | ** pod type 1325 | https://kubernetes.io/docs/tasks/debug-application-cluster/debug-application/#my-service-is-missing-endpoints 1326 | #+BEGIN_EXAMPLE 1327 | ... 1328 | spec: 1329 | - selector: 1330 | name: nginx 1331 | type: frontend 1332 | #+END_EXAMPLE 1333 | 1334 | kubectl get pods --selector=name=nginx,type=frontend 1335 | ** Containers inside a Pod can communicate with one another using localhost. 1336 | https://kubernetes.io/docs/concepts/workloads/pods/pod-overview/ 1337 | 1338 | Networking 1339 | Each Pod is assigned a unique IP address. Every container in a Pod shares the network namespace, including the IP address and network ports. Containers inside a Pod can communicate with one another using localhost. When containers in a Pod communicate with entities outside the Pod, they must coordinate how they use the shared network resources (such as ports). 1340 | ** How to restart a container inside a Pod? 1341 | https://kubernetes.io/docs/concepts/workloads/pods/pod-overview/ 1342 | 1343 | Restarting a container in a Pod should not be confused with restarting the Pod. The Pod itself does not run, but is an environment the containers run in and persists until it is deleted. 1344 | ** explain k8s components: apiserver, scheduler, controller-manager, kube-proxy 1345 | ** get logs of failed container 1346 | https://kubernetes.io/docs/tasks/debug-application-cluster/debug-application/#my-pod-is-crashing-or-otherwise-unhealthy 1347 | #+BEGIN_EXAMPLE 1348 | If your container has previously crashed, you can access the previous container's crash log with: 1349 | 1350 | $ kubectl logs --previous ${POD_NAME} ${CONTAINER_NAME} 1351 | #+END_EXAMPLE 1352 | ** Why k8s dashboard get deprecated? 1353 | https://kubernetes.io/docs/tasks/access-application-cluster/web-ui-dashboard/ 1354 | * TODO k8s architecture :noexport: 1355 | https://www.youtube.com/watch?v=_WfJz5VS_cU&list=PLj6h78yzYM2NGwRwkBPxigKio2r0XHPl9 1356 | * TODO k8s scenario problems :noexport: 1357 | ** TODO export k8s dashboard: kube proxy VS ingress 1358 | ** TODO how to back and restore etcd 1359 | https://kubernetes-incubator.github.io/kube-aws/advanced-topics/etcd-backup-and-restore.html 1360 | * TODO Apply yamls file recursively :noexport: 1361 | #+BEGIN_SRC sh 1362 | # create 1363 | time ls -1 */*.yml | grep -v namespace | xargs -I{} kubectl apply -f {} 1364 | 1365 | # delete 1366 | time ls -1r */*.yml | grep -v namespace | xargs -I{} kubectl delete -f {} 1367 | #+END_SRC 1368 | * TODO devstats: https://k8s.devstats.cncf.io/d/12/dashboards?refresh=15m&orgId=1 :noexport: 1369 | * TODO create a ingress service for clusterip service :noexport: 1370 | * TODO kubectl -vvv :noexport: 1371 | * TODO kubectl get application --all-namespaces :noexport: 1372 | * TODO kubectl delete namespace in GKE is extremely slow :noexport: 1373 | * TODO try more with ReplicaSet :noexport: 1374 | * TODO try PodDisruptionBudget: https://hackernoon.com/top-10-kubernetes-tips-and-tricks-27528c2d0222 :noexport: 1375 | * TODO [#A] k8s services :noexport: 1376 | https://medium.com/google-cloud/kubernetes-nodeport-vs-loadbalancer-vs-ingress-when-should-i-use-what-922f010849e0 1377 | * [#A] ClusterIP :noexport: 1378 | ** TODO kubernetes clusterip 1379 | ** TODO Is k8s ClusterIP SPOF? 1380 | https://mp.weixin.qq.com/s?__biz=MzIzNjUxMzk2NQ==&mid=2247486025&idx=1&sn=1f95917918a3217bb92b97113c81b6c8&chksm=e8d7f58bdfa07c9dedbfbe4f39687ea5d467ec371ecb2dea5dd13101a46d3bb754d6738e481f&scene=27#wechat_redirect 1381 | ** TODO Use ExternalName to avoid ClusterIP SPOF 1382 | * TODO k8s cpu 88m? :noexport: 1383 | #+BEGIN_EXAMPLE 1384 | Limits: 1385 | cpu: 48m 1386 | memory: 104Mi 1387 | Requests: 1388 | cpu: 48m 1389 | memory: 104Mi 1390 | 1391 | #+END_EXAMPLE 1392 | * TODO autoscaling pod: try auto scaling :noexport: 1393 | * TODO k8s volume: readwriteonce, readwritemany? :noexport: 1394 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1395 | * TODO grant more privileges to a given serviceaccount :noexport: 1396 | kubectl get serviceaccount --all-namespaces 1397 | 1398 | prometheus-1-prometheusserviceaccount-e1fd 1399 | 1400 | system:kubelet-api-admin 1401 | * TODO Question: PodDisruptionBudget: https://docs.pivotal.io/runtimes/pks/1-2/troubleshoot-issues.html#upgrade-drain-hangs :noexport: 1402 | If Kubernetes is unable to unschedule a pod, then the drain hangs indefinitely. 1403 | 1404 | One reason why Kubernetes may be unable to unschedule the node is if 1405 | the PodDisruptionBudget object has been configured in a way that 1406 | allows 0 disruptions and only a single instance of the pod has been 1407 | scheduled. 1408 | * TODO k8s events :noexport: 1409 | https://solinea.com/blog/tapping-kubernetes-events 1410 | * TODO kubectl from worker vm, I don't seem to need a kubeconfig :noexport: 1411 | * TODO kubectl apply -f - :noexport: 1412 | * TODO How does "kubectl delete - f -" works? :noexport: 1413 | * TODO devstats: https://k8s.devstats.cncf.io/d/12/dashboards?refresh=15m&orgId=1 :noexport: 1414 | * TODO Is it possible to assign a DNS address to Kubernetes service :noexport: 1415 | * TODO k8s template templateinstance :noexport: 1416 | * TODO [#A] k8s yaml create a loadbalancer :noexport: 1417 | * TODO github improvememnt: update k8s cheatsheet: https://blog.billyc.io/notes/kubectl-notes/ :noexport: 1418 | https://kubernetes.io/docs/reference/kubectl/cheatsheet/ 1419 | * [#A] Google Kubernetes :noexport:IMPORTANT: 1420 | No.2 Kubernetes 1421 | 1422 | Kubernetes是一个编排（orchestration）工具,类似运行于Apache Mesos之上的Marathon,但是它是专门为Docker容器而创建的. 1423 | 1424 | Kubernetes is an open-source platform for automating deployment, scaling, and operations of application containers across clusters of hosts, providing container-centric infrastructure 1425 | 1426 | Kubernetes来自Google,除了能在他们自己的Google Container Engine上工作之外,还支持VMware vSphere, Mesos, or Mesosphere DCOS,以及很多公有云,包括Amazon Web Services等. 1427 | 1428 | Kubernetes 具备完善的集群管理能力,包括多层次的安全防护和准入机制`多租户应用支撑能力`透明的服务注册和服务发现机制`内建负载均衡器`故障发现和自我修复能力`服务滚动升级和在线扩容`可扩展的资源自动调度机制`多粒度的资源配额管理能力. 1429 | 1430 | Kubernetes 还提供完善的管理工具,涵盖开发`部署测试`运维监控等各个环节. 1431 | 1432 | 每个API对象都有3大类属性:元数据metadata`规范spec和状态status 1433 | 1434 | - Concepts: Pod, Service, Labels和单Pod单IP 1435 | ** Installing and Setting Up kubectl 1436 | https://kubernetes.io/docs/tasks/tools/install-kubectl/ 1437 | 1438 | curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl 1439 | ** kubectl --help 1440 | kubectl controls the Kubernetes cluster manager. 1441 | 1442 | Find more information at https://github.com/kubernetes/kubernetes. 1443 | 1444 | Basic Commands (Beginner): 1445 | create Create a resource by filename or stdin 1446 | expose Take a replication controller, service, deployment or pod and expose it as a new Kubernetes Service 1447 | run Run a particular image on the cluster 1448 | set Set specific features on objects 1449 | 1450 | Basic Commands (Intermediate): 1451 | get Display one or many resources 1452 | explain Documentation of resources 1453 | edit Edit a resource on the server 1454 | delete Delete resources by filenames, stdin, resources and names, or by resources and label selector 1455 | 1456 | Deploy Commands: 1457 | rollout Manage a deployment rollout 1458 | rolling-update Perform a rolling update of the given ReplicationController 1459 | scale Set a new size for a Deployment, ReplicaSet, Replication Controller, or Job 1460 | autoscale Auto-scale a Deployment, ReplicaSet, or ReplicationController 1461 | 1462 | Cluster Management Commands: 1463 | certificate Modify certificate resources. 1464 | cluster-info Display cluster info 1465 | top Display Resource (CPU/Memory/Storage) usage. 1466 | cordon Mark node as unschedulable 1467 | uncordon Mark node as schedulable 1468 | drain Drain node in preparation for maintenance 1469 | taint Update the taints on one or more nodes 1470 | 1471 | Troubleshooting and Debugging Commands: 1472 | describe Show details of a specific resource or group of resources 1473 | logs Print the logs for a container in a pod 1474 | attach Attach to a running container 1475 | exec Execute a command in a container 1476 | port-forward Forward one or more local ports to a pod 1477 | proxy Run a proxy to the Kubernetes API server 1478 | cp Copy files and directories to and from containers. 1479 | auth Inspect authorization 1480 | Advanced Commands: 1481 | apply Apply a configuration to a resource by filename or stdin 1482 | patch Update field(s) of a resource using strategic merge patch 1483 | replace Replace a resource by filename or stdin 1484 | convert Convert config files between different API versions 1485 | 1486 | Settings Commands: 1487 | label Update the labels on a resource 1488 | annotate Update the annotations on a resource 1489 | completion Output shell completion code for the specified shell (bash or zsh) 1490 | 1491 | Other Commands: 1492 | api-versions Print the supported API versions on the server, in the form of "group/version" 1493 | config Modify kubeconfig files 1494 | help Help about any command 1495 | version Print the client and server version information 1496 | 1497 | Use "kubectl --help" for more information about a given command. 1498 | Use "kubectl options" for a list of global command-line options (applies to all commands). 1499 | ** kubernetes: The connection to the server localhost:8080 was refused - did you specify the right host or port? 1500 | https://github.com/kubernetes/kubernetes/issues/23092 1501 | ** Layers 1502 | - Nucleus: API And Execution 1503 | - Application layer: deployment and running 1504 | - Governance layer: automation and policy enforcement 1505 | - Interface layer: client libraries and tools 1506 | - Ecosystem 1507 | ** healthcheck: LivenessProbe, ReadinessProbe 1508 | ** 核心组件 1509 | Kubernetes主要由以下几个核心组件组成: 1510 | - etcd保存了整个集群的状态; 1511 | - apiserver提供了资源操作的唯一入口,并提供认证`授权`访问控制`API注册和发现等机制; 1512 | - controller manager负责维护集群的状态,比如故障检测`自动扩展`滚动更新等; 1513 | - scheduler负责资源的调度,按照预定的调度策略将Pod调度到相应的机器上; 1514 | - kubelet负责维护容器的生命周期,同时也负责Volume（CVI）和网络（CNI）的管理; 1515 | - Container runtime负责镜像管理以及Pod和容器的真正运行（CRI）; 1516 | - kube-proxy负责为Service提供cluster内部的服务发现和负载均衡 1517 | ** helloworld 1518 | https://kubernetes.io/docs/tutorials/stateless-application/hello-minikube/ 1519 | ** useful link 1520 | https://kubernetes.io 1521 | https://www.reddit.com/r/devops/comments/51ra9q/moving_from_docker_to_rkt/ 1522 | http://blog.dataman-inc.com/67/ 1523 | http://jpadilla.com/post/161144157937/update-kubernetes-deployment-after-pushing-image 1524 | https://spacelift.io/blog/kubernetes-cheat-sheet 1525 | 1526 | http://www.oschina.net/news/70140/infoworlds-2016-technology-of-the-year-award-winners?p=3#comments 1527 | ** DONE Principle: API的操作复杂度不能超过O(N) 1528 | CLOSED: [2017-06-10 Sat 15:24] 1529 | https://kubernetes.feisky.xyz/architecture/concepts.html 1530 | API操作复杂度与对象数量成正比.这一条主要是从系统性能角度考虑,要保证整个系统随着系统规模的扩大,性能不会迅速变慢到无法使用,那么最低的限定就是API的操作复杂度不能超过O(N),N是对象的数量,否则系统就不具备水平伸缩性了. 1531 | ** Principle: API对象状态不能依赖于网络连接状态 1532 | https://kubernetes.feisky.xyz/architecture/concepts.html 1533 | ** # --8<-------------------------- separator ------------------------>8-- 1534 | ** TODO [#A] fail to start minikube: "VBoxManage not found. Make sure VirtualBox is installed and VBoxManage is in the path". 1535 | root@totvsjenkins:/tmp# minikube start 1536 | Starting local Kubernetes v1.6.4 cluster... 1537 | Starting VM... 1538 | E0610 20:14:57.518198 27907 start.go:127] Error starting host: Error creating host: Error with pre-create check: "VBoxManage not found. Make sure VirtualBox is installed and VBoxManage is in the path". 1539 | 1540 | Retrying. 1541 | E0610 20:14:57.519201 27907 start.go:133] Error starting host: Error creating host: Error with pre-create check: "VBoxManage not found. Make sure VirtualBox is installed and VBoxManage is in the path" 1542 | ** TODO how kubernetes use etcd 1543 | ** TODO how healthcheck is implemented 1544 | ** TODO What about alerting and reporting 1545 | ** TODO what's fluentd 1546 | ** # --8<-------------------------- separator ------------------------>8-- 1547 | ** TODO [#A] k8s support rolling deployment :IMPORTANT: 1548 | https://www.youtube.com/watch?v=7TOWLerX0Ps 1549 | Kubernetes: zero downtime update at 1 million requests per second 1550 | https://www.youtube.com/watch?v=9C6YeyyUUmI 1551 | Kubernetes: zero downtime update at 10 million QPS 1552 | ** TODO [#A] How to scale Pods with volumes configured :IMPORTANT: 1553 | ** What is Kubernetes 1554 | https://www.youtube.com/watch?v=R-3dfURb2hA 1555 | What is Kubernetes 1556 | 1557 | Deployment, Scaling, Monitoring 1558 | ** DONE Kubernetes hellworld 1559 | CLOSED: [2017-07-11 Tue 08:42] 1560 | https://kubernetes.io/docs/tutorials/stateless-application/hello-minikube/#create-a-minikube-cluster 1561 | 1562 | # build image 1563 | docker build -t hello-node:v1 . 1564 | 1565 | # create deployment 1566 | kubectl run hello-node --image=hello-node:v1 --port=8080 1567 | 1568 | # View the Deployment 1569 | kubectl get deployments 1570 | 1571 | # Create service 1572 | kubectl expose deployment hello-node --type=LoadBalancer 1573 | ** TODO [#A] Install minikube in headless Ubuntu server :IMPORTANT: 1574 | | Name | Summary | 1575 | |-----------------+---------| 1576 | | minikube status | | 1577 | ** DONE [#A] Ubuntu install kubernetes for all-in-one POC: minikube 1578 | CLOSED: [2017-07-11 Tue 08:43] 1579 | https://blog.jetstack.io/blog/k8s-getting-started-part2/ 1580 | https://github.com/kubernetes/minikube 1581 | https://stackoverflow.com/questions/38528762/kubernetes-on-ubuntu-16-04 1582 | https://hxquangnhat.com/2016/12/21/tutorial-deploy-a-kubernetes-cluster-on-ubuntu-16-04/ 1583 | *** TODO minikube fail to start 1584 | #+BEGIN_EXAMPLE 1585 | root@totvsjenkins:/home/denny/minikube# ./minikube start --vm-driver=none --use-vendored-driver 1586 | Starting local Kubernetes v1.6.4 cluster... 1587 | Starting VM... 1588 | Moving files into cluster... 1589 | 1590 | Setting up certs... 1591 | Starting cluster components... 1592 | Connecting to cluster... 1593 | Setting up kubeconfig... 1594 | Kubectl is now configured to use the cluster. 1595 | =================== 1596 | WARNING: IT IS RECOMMENDED NOT TO RUN THE NONE DRIVER ON PERSONAL WORKSTATIONS 1597 | The 'none' driver will run an insecure kubernetes apiserver as root that may leave the host vulnerable to CSRF attacks 1598 | #+END_EXAMPLE 1599 | *** useful link 1600 | https://www.youtube.com/watch?v=PH-2FfFD2PU 1601 | Kubernetes in 5 mins 1602 | https://www.youtube.com/watch?v=DC7NECq3Ghs 1603 | Setting up and using a single node Kubernetes cluster. 1604 | https://www.youtube.com/watch?v=BDrcUjOczsE 1605 | Kubernetes - Local Testing 1606 | 1607 | https://www.youtube.com/watch?v=R-3dfURb2hA 1608 | The Illustrated Children's Guide to Kubernetes 1609 | 1610 | * TODO [#A] Run a task on every node in a cluster :noexport: 1611 | * TODO kubectl get all won't get psp :noexport: 1612 | #+BEGIN_EXAMPLE 1613 | root@009069ee-95d5-49a2-6b82-67aff8eb6737:/tmp/build/4ecf0f02# kubectl get all --all-namespaces 1614 | NAMESPACE NAME READY STATUS RESTARTS AGE 1615 | kube-system pod/heapster-6d5f964dbd-2xxcm 1/1 Running 0 1d 1616 | kube-system pod/kube-dns-6b697fcdbd-c4rmm 3/3 Running 0 1d 1617 | kube-system pod/kubernetes-dashboard-785584f46b-9wmqj 1/1 Running 0 1d 1618 | kube-system pod/metrics-server-6bbb689cf9-swtxc 1/1 Running 0 1d 1619 | kube-system pod/monitoring-influxdb-76fd8dcff6-qws9m 1/1 Running 0 1d 1620 | kube-system pod/wavefront-proxy-8498d5bbf4-gl6sw 4/4 Running 0 4m 1621 | test-afjogacpjsqfetejycxx pod/busybox-io-ftpz8 1/1 Running 0 1d 1622 | 1623 | NAMESPACE NAME DESIRED CURRENT READY AGE 1624 | test-afjogacpjsqfetejycxx replicationcontroller/busybox-io 1 1 1 1d 1625 | 1626 | NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE 1627 | default service/kubernetes ClusterIP 10.100.200.1 443/TCP 1d 1628 | kube-system service/heapster ClusterIP 10.100.200.123 8443/TCP 1d 1629 | kube-system service/kube-dns ClusterIP 10.100.200.10 53/UDP,53/TCP 1d 1630 | kube-system service/kubernetes-dashboard NodePort 10.100.200.8 443:32433/TCP 1d 1631 | kube-system service/metrics-server ClusterIP 10.100.200.102 443/TCP 1d 1632 | kube-system service/monitoring-influxdb ClusterIP 10.100.200.89 8086/TCP 1d 1633 | 1634 | NAMESPACE NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE 1635 | kube-system deployment.apps/heapster 1 1 1 1 1d 1636 | kube-system deployment.apps/kube-dns 1 1 1 1 1d 1637 | kube-system deployment.apps/kubernetes-dashboard 1 1 1 1 1d 1638 | kube-system deployment.apps/metrics-server 1 1 1 1 1d 1639 | kube-system deployment.apps/monitoring-influxdb 1 1 1 1 1d 1640 | kube-system deployment.apps/wavefront-proxy 1 1 1 1 4m 1641 | 1642 | NAMESPACE NAME DESIRED CURRENT READY AGE 1643 | kube-system replicaset.apps/heapster-6d5f964dbd 1 1 1 1d 1644 | kube-system replicaset.apps/kube-dns-6b697fcdbd 1 1 1 1d 1645 | kube-system replicaset.apps/kubernetes-dashboard-785584f46b 1 1 1 1d 1646 | kube-system replicaset.apps/metrics-server-6bbb689cf9 1 1 1 1d 1647 | kube-system replicaset.apps/monitoring-influxdb-76fd8dcff6 1 1 1 1d 1648 | kube-system replicaset.apps/wavefront-proxy-8498d5bbf4 1 1 1 4m 1649 | root@009069ee-95d5-49a2-6b82-67aff8eb6737:/tmp/build/4ecf0f02# kubectl get psp 1650 | NAME PRIV CAPS SELINUX RUNASUSER FSGROUP SUPGROUP READONLYROOTFS VOLUMES 1651 | kube-system-psp false * RunAsAny RunAsAny RunAsAny RunAsAny false configMap,emptyDir,projected,secret,downwardAPI 1652 | root@009069ee-95d5-49a2-6b82-67aff8eb6737:/tmp/build/4ecf0f02# kubectl get all --all-namespaces | grep kube-system-psp 1653 | #+END_EXAMPLE 1654 | * TODO where is k8s job log? :noexport: 1655 | http://kubernetesbyexample.com/jobs/ 1656 | * TODO kubectl logs --previous nginx-app-zibvs :noexport: 1657 | https://jimmysong.io/cheatsheets/kubernetes-kubectl 1658 | * TODO [#A] play with k8s ingress service :noexport: 1659 | * TODO Vanilla CNCF Certified Kubernetes :noexport: 1660 | * TODO [#A] try admission controller :noexport: 1661 | * HALF Accessing Kubernetes API from pods :noexport: 1662 | curl -k -v --cacert /var/run/secrets/kubernetes.io/serviceaccount/ca.crt -H "Authorization: Bearer $(cat /var/run/secrets/kubernetes.io/serviceaccount/token)" https:// 1663 | * TODO k8s training course from linux foundation: https://training.linuxfoundation.org/training/introduction-to-kubernetes/ :noexport: 1664 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1665 | * TODO consolidate: https://codefresh.io/kubernetes-tutorial/page/4/ :noexport: 1666 | * TODO consolidate: https://info.shadow-soft.com/hubfs/Kubernetes-Cheatsheet-Mesosphere.pdf :noexport: 1667 | * TODO consolidate: https://kapeli.com/cheat_sheets/Kubernetes.docset/Contents/Resources/Documents/index :noexport: 1668 | * TODO consolidate: https://lzone.de/cheat-sheet/kubernetes :noexport: 1669 | * TODO consolidate: http://www.productiondown.com/devops/2018/08/02/Kubernetes-Commands-Cheatsheet.html :noexport: 1670 | * TODO consolidate cheatsheet: https://github.com/LeCoupa/awesome-cheatsheets/blob/master/tools/kubernetes.sh :noexport: 1671 | * TODO consolidate: http://kubernetesbyexample.com/ :noexport: 1672 | * TODO consolidate https://jimmysong.io/cheatsheets/kubernetes-tricks :noexport: 1673 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1674 | * HALF use kubectl to pull docker images, instead of ssh to vm :noexport: 1675 | * HALF use kubectl to cleanup docker images, instead of ssh to vm :noexport: 1676 | https://github.com/onfido/k8s-cleanup/blob/master/docker-clean.yml 1677 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1678 | * TODO pv termination hangs there forever :noexport: 1679 | #+BEGIN_EXAMPLE 1680 |  /Users/zdenny/git_code/codecommit/devops_blog/k8s  kubectl get pv   master ✘ ✹  ✔ 0 1681 | NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE 1682 | db-pv-volume 400Gi RWO Retain Available 12h 1683 | pvc-bbddb940-5f43-11e9-ba3c-42010a800085 1Gi RWO Delete Bound denny-websites/cdn-pv-claim standard 12h 1684 | website-pv-volume 10Gi RWO Retain Terminating denny-websites/mysql-pv-claim standard 12h 1685 | #+END_EXAMPLE 1686 | * TODO k8s configmap can't be changed :noexport: 1687 | #+BEGIN_EXAMPLE 1688 |  /Users/zdenny/git_code/codecommit/devops_blog/k8s  kubectl logs -n denny-websites pod/nginx-b88c67f77-dkw64   master ✘ ✖ ✹ ✭  ✔ 0 1689 | Update /etc/nginx/conf.d/default.conf 1690 | + echo 'Update /etc/nginx/conf.d/default.conf' 1691 | + sed -i s/http_port_here/80/g /etc/nginx/conf.d/default.conf 1692 | sed: cannot rename /etc/nginx/conf.d/sedz2uuPB: Device or resource busy 1693 | #+END_EXAMPLE 1694 | * TODO [#A] k8s mount configmap file, then edit it when process boostrap :noexport: 1695 | * TODO gce disk: how and when the filesystem formating happens? :noexport: 1696 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1697 | * TODO k8s pod share volume within containers :noexport: 1698 | * TODO gce use one disk in a small chunks :noexport: 1699 | * TODO k8s mount jenkins home volume, then dockerfile copy/jenkins groovy. How to align? :noexport: 1700 | COPY resources/jobs/ /usr/share/jenkins/ref/jobs/ 1701 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1702 | * TODO k8s: when jenkins pod gets recreated, jenkins secret parameters need to be reconfigured :noexport: 1703 | * TODO k8s: instruct application to run a clean shutdown or a safe restart :noexport: 1704 | https://support.cloudbees.com/hc/en-us/articles/115003926511-Best-Practices-for-Jenkins-Updates-Patches-and-Maintenance 1705 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1706 | * HALF doc: configmap cannot be mounted as a file :noexport: 1707 | https://stackoverflow.com/questions/44325048/kubernetes-configmap-only-one-file 1708 | 1709 | ConfigMaps must be mounted as directories 1710 | 1711 | https://github.com/kubernetes/kubernetes/issues/45000 1712 | https://stackoverflow.com/questions/44325048/kubernetes-configmap-only-one-file 1713 | * HALF doc: mount configmap as a seperate file :noexport: 1714 | * TODO How to pass credentials to yaml in a secured way? :noexport: 1715 | * TODO kubectl cluster-info only get recent information :noexport: 1716 | * DONE k8s pod dns :noexport: 1717 | CLOSED: [2019-05-25 Sat 08:21] 1718 | https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/ 1719 | 1720 | _my-port-name._my-port-protocol.my-svc.my-namespace.svc.cluster.local 1721 | 1722 | curl -I http://jenkins-lb.my-testbed.svc.cluster.local 1723 | * DONE why one pod has two docker images :noexport: 1724 | CLOSED: [2019-08-01 Thu 14:31] 1725 | One pod with two containers 1726 | #+BEGIN_EXAMPLE 1727 | root@422e158feb46fff15217b24e4f8ad20b [ ~ ]# kubectl get pods -o='custom-columns=PODS:.metadata.name,Images:.spec.containers[*].image' --all-namespaces | grep sche 1728 | kube-scheduler-422e158feb46fff15217b24e4f8ad20b my/kube-scheduler:v1.13.1,my/wcp-schedext:0.0.1.26323453 1729 | #+END_EXAMPLE 1730 | * DONE kubectl get port nodeport :noexport: 1731 | CLOSED: [2020-04-16 Thu 10:57] 1732 | kubectl get service/wordpress -n blog -o json | jq '.spec.ports[].nodePort' 1733 | 1734 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1735 | * TODO [#B] Create PVC workflow :noexport: 1736 | * TODO [#B] Create CRD workflow :noexport: 1737 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1738 | * TODO Why we need kube-controller-manager :noexport: 1739 | * TODO Why we need cluster-controller-manager :noexport: 1740 | * # --8<-------------------------- separator ------------------------>8-- :noexport: 1741 | * TODO k8s volume: CSI, vmdk, NFS :noexport: 1742 | * TODO k8s dynamic PV provision vs static PV provision :noexport: 1743 | * TODO [#A] k8s delete namespace hang :noexport: 1744 | Related resources need to be deleted first 1745 | * TODO [#A] k8s debugging loadbalancer service: external ip in state :noexport: 1746 | #+BEGIN_EXAMPLE 1747 | $ kubectl get svc -n blog 1748 | NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE 1749 | mysql ClusterIP 100.69.173.237 3306/TCP 12m 1750 | wordpress LoadBalancer 100.66.31.190 80:30407/TCP 12m 1751 | 1752 | $ kubectl describe service/wordpress -n blog 1753 | Name: wordpress 1754 | Namespace: blog 1755 | Labels: app=wordpress 1756 | Annotations: Selector: app=wordpress 1757 | Type: LoadBalancer 1758 | IP: 100.66.31.190 1759 | Port: 80/TCP 1760 | TargetPort: 80/TCP 1761 | NodePort: 30407/TCP 1762 | Endpoints: 100.117.221.13:80 1763 | Session Affinity: None 1764 | External Traffic Policy: Cluster 1765 | Events: 1766 | 10:34 1767 | 1768 | $ cat 21-wordpress-service.yaml 1769 | apiVersion: v1 1770 | kind: Service 1771 | metadata: 1772 | labels: 1773 | app: wordpress 1774 | namespace: blog 1775 | name: wordpress 1776 | spec: 1777 | type: LoadBalancer 1778 | ports: 1779 | - port: 80 1780 | targetPort: 80 1781 | protocol: TCP 1782 | selector: 1783 | app: wordpress 1784 | #+END_EXAMPLE 1785 | * TODO K8s networking :noexport: 1786 | - container-to-container communication 1787 | - pod-to-pod communication 1788 | K8s itself won't do it for you. And CNI can be used to configure the network of a pod and provide a single IP per pod. 1789 | CNI doesn't help you with pod-to-pod communication across nodes. 1790 | - external-to-pod communication 1791 | * Questions forked from CKA preparation :noexport: 1792 | ** TODO how etcd is designed and implemented? 1793 | ** TODO [#A] Only one IP address per Pod. How multiple containers talk with each other inside one pod? 1794 | Two containers share the same network namespace of the thrid container, known as the pause container. 1795 | 1796 | - The pause container is used to get an IP address, then all containers in the pod will uses its network namespace. 1797 | - To communicate with each other, containers can use the loopback interface, write to files on a common filesystem, or via IPC 1798 | ** TODO Why ipv6 doesn't gain popularity 1799 | ipv6 not backward compatible 1800 | NAT 1801 | ipv4 better management 1802 | ** TODO How K8s reconcilation is done? 1803 | ** TODO How the feature of cluster ip is implemented? 1804 | -------------------------------------------------------------------------------- /cheatsheet-kubernetes-A4.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/dennyzhang/cheatsheet-kubernetes-A4/28218317dcacccb2ad443f090d825292823c315d/cheatsheet-kubernetes-A4.pdf -------------------------------------------------------------------------------- /get-pod-error-log.sh: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env bash 2 | ## @copyright 2019 DennyZhang.com 3 | ## Licensed under MIT 4 | ## https://www.dennyzhang.com/wp-content/mit_license.txt 5 | ## 6 | ## File: delete_all_containers.sh 7 | ## Author : Denny 8 | ## Description : https://cheatsheet.dennyzhang.com/cheatsheet-kubernetes-A4 9 | ## -- 10 | ## Created : <2018-07-10> 11 | ## Updated: Time-stamp: <2019-07-31 22:54:01> 12 | ##------------------------------------------------------------------- 13 | # curl -L https://raw.githubusercontent.com/dennyzhang/cheatsheet-kubernetes-A4/master/get-pod-error-log.sh | bash 14 | namespace=${1:-""} 15 | log_pattern="grep -iE 'exception|error' | grep -v 'Reconciler error' | tail -n10" 16 | 17 | if [ -z "$namespace" ]; then 18 | options="--all-namespaces" 19 | else 20 | options="-n $namespace" 21 | fi 22 | command="kubectl get pods -o='custom-columns=PODS:.metadata.name,PODS:.metadata.namespace' $options | grep -v PODS" 23 | echo "$command" 24 | pods=$(eval "$command") 25 | 26 | IFS=$'\n' 27 | for item in $pods; do 28 | pod=$(echo "$item" | awk '{print $1}') 29 | ns=$(echo "$item" | awk '{print $2}') 30 | command="kubectl logs pod/$pod -n $ns | $log_pattern" 31 | echo "$command" && eval "$command" 32 | done 33 | -------------------------------------------------------------------------------- /jenkinjavafile: -------------------------------------------------------------------------------- 1 | public class SortedIntList extends IntListVer3{ 2 | 3 | public SortedIntList(int initialCap){ 4 | //call IntList constructor 5 | super(initialCap); 6 | } 7 | 8 | public SortedIntList(){ 9 | super(); 10 | } 11 | 12 | //override add 13 | public void add(int value){ 14 | //search for location to insert value 15 | int pos = 0; 16 | while( pos < size() && value > get(pos) ){ 17 | pos++; 18 | } 19 | super.insert(pos, value); 20 | } 21 | 22 | } 23 | -------------------------------------------------------------------------------- /k8s-networking-ip.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/dennyzhang/cheatsheet-kubernetes-A4/28218317dcacccb2ad443f090d825292823c315d/k8s-networking-ip.png -------------------------------------------------------------------------------- /list-all-images.sh: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env bash 2 | ## @copyright 2018 DennyZhang.com 3 | ## Licensed under MIT 4 | ## https://www.dennyzhang.com/wp-content/mit_license.txt 5 | ## 6 | ## Author : Denny 7 | ## Description : 8 | ## https://cheatsheet.dennyzhang.com/cheatsheet-kubernetes-A4 9 | ## -- 10 | ## Created : <2018-07-17> 11 | ## Updated: Time-stamp: <2018-12-30 19:07:42> 12 | ##------------------------------------------------------------------- 13 | # https://kubernetes.io/docs/tasks/access-application-cluster/list-all-running-container-images/ 14 | kubectl get pods --all-namespaces -o jsonpath="{..image}" |\ 15 | tr -s '[[:space:]]' '\n' |\ 16 | sort |\ 17 | uniq -c 18 | -------------------------------------------------------------------------------- /skip-tls-verify.md: -------------------------------------------------------------------------------- 1 | ``` 2 | apiVersion: v1 3 | clusters: 4 | - cluster: 5 | server: https://192.168.0.100:8443 6 | insecure-skip-tls-verify: true 7 | name: minikube 8 | contexts: 9 | - context: 10 | cluster: minikube 11 | user: minikube 12 | name: minikube 13 | current-context: minikube 14 | kind: Config 15 | preferences: {} 16 | users: 17 | - name: minikube 18 | user: 19 | client-certificate: C:\Users\wes.robinson\.minikube\client.crt 20 | client-key: C:\Users\wes.robinson\.minikube\client.key 21 | ``` 22 | 23 | https://github.com/terraform-providers/terraform-provider-kubernetes/issues/189 --------------------------------------------------------------------------------