├── LICENSE ├── README.md ├── configmaps └── kube-dns.yaml ├── deployments └── consul.yaml ├── job └── dns.yaml ├── scripts └── bootstrap-consul-server.sh └── services └── consul-dns.yaml /LICENSE: -------------------------------------------------------------------------------- 1 | Mozilla Public License Version 2.0 2 | ================================== 3 | 4 | 1. Definitions 5 | -------------- 6 | 7 | 1.1. "Contributor" 8 | means each individual or legal entity that creates, contributes to 9 | the creation of, or owns Covered Software. 10 | 11 | 1.2. "Contributor Version" 12 | means the combination of the Contributions of others (if any) used 13 | by a Contributor and that particular Contributor's Contribution. 14 | 15 | 1.3. "Contribution" 16 | means Covered Software of a particular Contributor. 17 | 18 | 1.4. "Covered Software" 19 | means Source Code Form to which the initial Contributor has attached 20 | the notice in Exhibit A, the Executable Form of such Source Code 21 | Form, and Modifications of such Source Code Form, in each case 22 | including portions thereof. 23 | 24 | 1.5. "Incompatible With Secondary Licenses" 25 | means 26 | 27 | (a) that the initial Contributor has attached the notice described 28 | in Exhibit B to the Covered Software; or 29 | 30 | (b) that the Covered Software was made available under the terms of 31 | version 1.1 or earlier of the License, but not also under the 32 | terms of a Secondary License. 33 | 34 | 1.6. "Executable Form" 35 | means any form of the work other than Source Code Form. 36 | 37 | 1.7. "Larger Work" 38 | means a work that combines Covered Software with other material, in 39 | a separate file or files, that is not Covered Software. 40 | 41 | 1.8. "License" 42 | means this document. 43 | 44 | 1.9. "Licensable" 45 | means having the right to grant, to the maximum extent possible, 46 | whether at the time of the initial grant or subsequently, any and 47 | all of the rights conveyed by this License. 48 | 49 | 1.10. "Modifications" 50 | means any of the following: 51 | 52 | (a) any file in Source Code Form that results from an addition to, 53 | deletion from, or modification of the contents of Covered 54 | Software; or 55 | 56 | (b) any new file in Source Code Form that contains any Covered 57 | Software. 58 | 59 | 1.11. "Patent Claims" of a Contributor 60 | means any patent claim(s), including without limitation, method, 61 | process, and apparatus claims, in any patent Licensable by such 62 | Contributor that would be infringed, but for the grant of the 63 | License, by the making, using, selling, offering for sale, having 64 | made, import, or transfer of either its Contributions or its 65 | Contributor Version. 66 | 67 | 1.12. "Secondary License" 68 | means either the GNU General Public License, Version 2.0, the GNU 69 | Lesser General Public License, Version 2.1, the GNU Affero General 70 | Public License, Version 3.0, or any later versions of those 71 | licenses. 72 | 73 | 1.13. "Source Code Form" 74 | means the form of the work preferred for making modifications. 75 | 76 | 1.14. "You" (or "Your") 77 | means an individual or a legal entity exercising rights under this 78 | License. For legal entities, "You" includes any entity that 79 | controls, is controlled by, or is under common control with You. For 80 | purposes of this definition, "control" means (a) the power, direct 81 | or indirect, to cause the direction or management of such entity, 82 | whether by contract or otherwise, or (b) ownership of more than 83 | fifty percent (50%) of the outstanding shares or beneficial 84 | ownership of such entity. 85 | 86 | 2. License Grants and Conditions 87 | -------------------------------- 88 | 89 | 2.1. Grants 90 | 91 | Each Contributor hereby grants You a world-wide, royalty-free, 92 | non-exclusive license: 93 | 94 | (a) under intellectual property rights (other than patent or trademark) 95 | Licensable by such Contributor to use, reproduce, make available, 96 | modify, display, perform, distribute, and otherwise exploit its 97 | Contributions, either on an unmodified basis, with Modifications, or 98 | as part of a Larger Work; and 99 | 100 | (b) under Patent Claims of such Contributor to make, use, sell, offer 101 | for sale, have made, import, and otherwise transfer either its 102 | Contributions or its Contributor Version. 103 | 104 | 2.2. Effective Date 105 | 106 | The licenses granted in Section 2.1 with respect to any Contribution 107 | become effective for each Contribution on the date the Contributor first 108 | distributes such Contribution. 109 | 110 | 2.3. Limitations on Grant Scope 111 | 112 | The licenses granted in this Section 2 are the only rights granted under 113 | this License. No additional rights or licenses will be implied from the 114 | distribution or licensing of Covered Software under this License. 115 | Notwithstanding Section 2.1(b) above, no patent license is granted by a 116 | Contributor: 117 | 118 | (a) for any code that a Contributor has removed from Covered Software; 119 | or 120 | 121 | (b) for infringements caused by: (i) Your and any other third party's 122 | modifications of Covered Software, or (ii) the combination of its 123 | Contributions with other software (except as part of its Contributor 124 | Version); or 125 | 126 | (c) under Patent Claims infringed by Covered Software in the absence of 127 | its Contributions. 128 | 129 | This License does not grant any rights in the trademarks, service marks, 130 | or logos of any Contributor (except as may be necessary to comply with 131 | the notice requirements in Section 3.4). 132 | 133 | 2.4. Subsequent Licenses 134 | 135 | No Contributor makes additional grants as a result of Your choice to 136 | distribute the Covered Software under a subsequent version of this 137 | License (see Section 10.2) or under the terms of a Secondary License (if 138 | permitted under the terms of Section 3.3). 139 | 140 | 2.5. Representation 141 | 142 | Each Contributor represents that the Contributor believes its 143 | Contributions are its original creation(s) or it has sufficient rights 144 | to grant the rights to its Contributions conveyed by this License. 145 | 146 | 2.6. Fair Use 147 | 148 | This License is not intended to limit any rights You have under 149 | applicable copyright doctrines of fair use, fair dealing, or other 150 | equivalents. 151 | 152 | 2.7. Conditions 153 | 154 | Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted 155 | in Section 2.1. 156 | 157 | 3. Responsibilities 158 | ------------------- 159 | 160 | 3.1. Distribution of Source Form 161 | 162 | All distribution of Covered Software in Source Code Form, including any 163 | Modifications that You create or to which You contribute, must be under 164 | the terms of this License. You must inform recipients that the Source 165 | Code Form of the Covered Software is governed by the terms of this 166 | License, and how they can obtain a copy of this License. You may not 167 | attempt to alter or restrict the recipients' rights in the Source Code 168 | Form. 169 | 170 | 3.2. Distribution of Executable Form 171 | 172 | If You distribute Covered Software in Executable Form then: 173 | 174 | (a) such Covered Software must also be made available in Source Code 175 | Form, as described in Section 3.1, and You must inform recipients of 176 | the Executable Form how they can obtain a copy of such Source Code 177 | Form by reasonable means in a timely manner, at a charge no more 178 | than the cost of distribution to the recipient; and 179 | 180 | (b) You may distribute such Executable Form under the terms of this 181 | License, or sublicense it under different terms, provided that the 182 | license for the Executable Form does not attempt to limit or alter 183 | the recipients' rights in the Source Code Form under this License. 184 | 185 | 3.3. Distribution of a Larger Work 186 | 187 | You may create and distribute a Larger Work under terms of Your choice, 188 | provided that You also comply with the requirements of this License for 189 | the Covered Software. If the Larger Work is a combination of Covered 190 | Software with a work governed by one or more Secondary Licenses, and the 191 | Covered Software is not Incompatible With Secondary Licenses, this 192 | License permits You to additionally distribute such Covered Software 193 | under the terms of such Secondary License(s), so that the recipient of 194 | the Larger Work may, at their option, further distribute the Covered 195 | Software under the terms of either this License or such Secondary 196 | License(s). 197 | 198 | 3.4. Notices 199 | 200 | You may not remove or alter the substance of any license notices 201 | (including copyright notices, patent notices, disclaimers of warranty, 202 | or limitations of liability) contained within the Source Code Form of 203 | the Covered Software, except that You may alter any license notices to 204 | the extent required to remedy known factual inaccuracies. 205 | 206 | 3.5. Application of Additional Terms 207 | 208 | You may choose to offer, and to charge a fee for, warranty, support, 209 | indemnity or liability obligations to one or more recipients of Covered 210 | Software. However, You may do so only on Your own behalf, and not on 211 | behalf of any Contributor. You must make it absolutely clear that any 212 | such warranty, support, indemnity, or liability obligation is offered by 213 | You alone, and You hereby agree to indemnify every Contributor for any 214 | liability incurred by such Contributor as a result of warranty, support, 215 | indemnity or liability terms You offer. You may include additional 216 | disclaimers of warranty and limitations of liability specific to any 217 | jurisdiction. 218 | 219 | 4. Inability to Comply Due to Statute or Regulation 220 | --------------------------------------------------- 221 | 222 | If it is impossible for You to comply with any of the terms of this 223 | License with respect to some or all of the Covered Software due to 224 | statute, judicial order, or regulation then You must: (a) comply with 225 | the terms of this License to the maximum extent possible; and (b) 226 | describe the limitations and the code they affect. Such description must 227 | be placed in a text file included with all distributions of the Covered 228 | Software under this License. Except to the extent prohibited by statute 229 | or regulation, such description must be sufficiently detailed for a 230 | recipient of ordinary skill to be able to understand it. 231 | 232 | 5. Termination 233 | -------------- 234 | 235 | 5.1. The rights granted under this License will terminate automatically 236 | if You fail to comply with any of its terms. However, if You become 237 | compliant, then the rights granted under this License from a particular 238 | Contributor are reinstated (a) provisionally, unless and until such 239 | Contributor explicitly and finally terminates Your grants, and (b) on an 240 | ongoing basis, if such Contributor fails to notify You of the 241 | non-compliance by some reasonable means prior to 60 days after You have 242 | come back into compliance. Moreover, Your grants from a particular 243 | Contributor are reinstated on an ongoing basis if such Contributor 244 | notifies You of the non-compliance by some reasonable means, this is the 245 | first time You have received notice of non-compliance with this License 246 | from such Contributor, and You become compliant prior to 30 days after 247 | Your receipt of the notice. 248 | 249 | 5.2. If You initiate litigation against any entity by asserting a patent 250 | infringement claim (excluding declaratory judgment actions, 251 | counter-claims, and cross-claims) alleging that a Contributor Version 252 | directly or indirectly infringes any patent, then the rights granted to 253 | You by any and all Contributors for the Covered Software under Section 254 | 2.1 of this License shall terminate. 255 | 256 | 5.3. In the event of termination under Sections 5.1 or 5.2 above, all 257 | end user license agreements (excluding distributors and resellers) which 258 | have been validly granted by You or Your distributors under this License 259 | prior to termination shall survive termination. 260 | 261 | ************************************************************************ 262 | * * 263 | * 6. Disclaimer of Warranty * 264 | * ------------------------- * 265 | * * 266 | * Covered Software is provided under this License on an "as is" * 267 | * basis, without warranty of any kind, either expressed, implied, or * 268 | * statutory, including, without limitation, warranties that the * 269 | * Covered Software is free of defects, merchantable, fit for a * 270 | * particular purpose or non-infringing. The entire risk as to the * 271 | * quality and performance of the Covered Software is with You. * 272 | * Should any Covered Software prove defective in any respect, You * 273 | * (not any Contributor) assume the cost of any necessary servicing, * 274 | * repair, or correction. This disclaimer of warranty constitutes an * 275 | * essential part of this License. No use of any Covered Software is * 276 | * authorized under this License except under this disclaimer. * 277 | * * 278 | ************************************************************************ 279 | 280 | ************************************************************************ 281 | * * 282 | * 7. Limitation of Liability * 283 | * -------------------------- * 284 | * * 285 | * Under no circumstances and under no legal theory, whether tort * 286 | * (including negligence), contract, or otherwise, shall any * 287 | * Contributor, or anyone who distributes Covered Software as * 288 | * permitted above, be liable to You for any direct, indirect, * 289 | * special, incidental, or consequential damages of any character * 290 | * including, without limitation, damages for lost profits, loss of * 291 | * goodwill, work stoppage, computer failure or malfunction, or any * 292 | * and all other commercial damages or losses, even if such party * 293 | * shall have been informed of the possibility of such damages. This * 294 | * limitation of liability shall not apply to liability for death or * 295 | * personal injury resulting from such party's negligence to the * 296 | * extent applicable law prohibits such limitation. Some * 297 | * jurisdictions do not allow the exclusion or limitation of * 298 | * incidental or consequential damages, so this exclusion and * 299 | * limitation may not apply to You. * 300 | * * 301 | ************************************************************************ 302 | 303 | 8. Litigation 304 | ------------- 305 | 306 | Any litigation relating to this License may be brought only in the 307 | courts of a jurisdiction where the defendant maintains its principal 308 | place of business and such litigation shall be governed by laws of that 309 | jurisdiction, without reference to its conflict-of-law provisions. 310 | Nothing in this Section shall prevent a party's ability to bring 311 | cross-claims or counter-claims. 312 | 313 | 9. Miscellaneous 314 | ---------------- 315 | 316 | This License represents the complete agreement concerning the subject 317 | matter hereof. If any provision of this License is held to be 318 | unenforceable, such provision shall be reformed only to the extent 319 | necessary to make it enforceable. Any law or regulation which provides 320 | that the language of a contract shall be construed against the drafter 321 | shall not be used to construe this License against a Contributor. 322 | 323 | 10. Versions of the License 324 | --------------------------- 325 | 326 | 10.1. New Versions 327 | 328 | Mozilla Foundation is the license steward. Except as provided in Section 329 | 10.3, no one other than the license steward has the right to modify or 330 | publish new versions of this License. Each version will be given a 331 | distinguishing version number. 332 | 333 | 10.2. Effect of New Versions 334 | 335 | You may distribute the Covered Software under the terms of the version 336 | of the License under which You originally received the Covered Software, 337 | or under the terms of any subsequent version published by the license 338 | steward. 339 | 340 | 10.3. Modified Versions 341 | 342 | If you create software not governed by this License, and you want to 343 | create a new license for such software, you may create and use a 344 | modified version of this License if you rename the license and remove 345 | any references to the name of the license steward (except to note that 346 | such modified license differs from this License). 347 | 348 | 10.4. Distributing Source Code Form that is Incompatible With Secondary 349 | Licenses 350 | 351 | If You choose to distribute Source Code Form that is Incompatible With 352 | Secondary Licenses under the terms of this version of the License, the 353 | notice described in Exhibit B of this License must be attached. 354 | 355 | Exhibit A - Source Code Form License Notice 356 | ------------------------------------------- 357 | 358 | This Source Code Form is subject to the terms of the Mozilla Public 359 | License, v. 2.0. If a copy of the MPL was not distributed with this 360 | file, You can obtain one at http://mozilla.org/MPL/2.0/. 361 | 362 | If it is not possible or desirable to put the notice in a particular 363 | file, then You may include the notice in a location (such as a LICENSE 364 | file in a relevant directory) where a recipient would be likely to look 365 | for such a notice. 366 | 367 | You may add additional accurate notices of copyright ownership. 368 | 369 | Exhibit B - "Incompatible With Secondary Licenses" Notice 370 | --------------------------------------------------------- 371 | 372 | This Source Code Form is "Incompatible With Secondary Licenses", as 373 | defined by the Mozilla Public License, v. 2.0. 374 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # consul-dns-for-kubernetes 2 | Consul DNS Interface for Kubernetes 3 | 4 | ## Overview 5 | 6 | In this tutorial we will learn how to configure Kubernetes ([kube-dns](https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/)) to discover services registered in Consul using Consul's DNS interface. 7 | 8 | ## Prerequisites 9 | 10 | This tutorial requires a Kubernetes cluster. 11 | 12 | * kubernetes 1.8.7 13 | 14 | ### Kubernetes cluster using Google Cloud Platform 15 | 16 | If you don't have a Kubernetes running, you can use [GKE](https://cloud.google.com/kubernetes-engine/) to start one up. 17 | 18 | **Installation** 19 | 20 | Install CLI tools for Google Cloud by downloading them [here](https://cloud.google.com/sdk/). 21 | 22 | Configure Google Cloud region and zone 23 | 24 | ```bash 25 | gcloud config set compute/region "us-west1" 26 | gcloud config set compute/zone "us-west1-b" 27 | ``` 28 | 29 | Create Kubernetes cluster 30 | 31 | ```bash 32 | gcloud beta container clusters create us-west1-b \ 33 | --cluster-version 1.8.7-gke.1 \ 34 | --machine-type n1-standard-2 \ 35 | --scopes "cloud-platform,storage-ro,logging-write,monitoring-write,service-control,service-management,https://www.googleapis.com/auth/ndev.clouddns.readwrite" 36 | ``` 37 | 38 | *The scopes above can be tailored towards the permissions you might need.* 39 | 40 | *This might take a few moments to complete.* 41 | 42 | ```bash 43 | Creating cluster us-west1-b...done. 44 | Created [https://container.googleapis.com/v1/projects/project-name/zones/us-west1-b/clusters/us-west1-b]. 45 | To inspect the contents of your cluster, go to: https://console.cloud.google.com/kubernetes/workload_/gcloud/us-west1-b/us-west1-b?project=project-name 46 | kubeconfig entry generated for us-west1-b. 47 | NAME LOCATION MASTER_VERSION MASTER_IP MACHINE_TYPE NODE_VERSION NUM_NODES STATUS 48 | us-west1-b us-west1-b 1.8.7-gke.1 35.203.190.18 n1-standard-2 1.8.7-gke.1 3 RUNNING 49 | ``` 50 | 51 | Save cluster credentials 52 | 53 | ```bash 54 | gcloud container clusters get-credentials us-west1-b 55 | ``` 56 | 57 | Validate Kubernetes cluster 58 | 59 | ```bash 60 | kubectl get componentstatus 61 | ``` 62 | 63 | ```bash 64 | NAME STATUS MESSAGE ERROR 65 | scheduler Healthy ok 66 | controller-manager Healthy ok 67 | etcd-0 Healthy {"health": "true"} 68 | etcd-1 Healthy {"health": "true"} 69 | ``` 70 | 71 | ### Clone Repository 72 | 73 | The Consul DNS Interface for Kubernetes repository holds deployment files, scripts, and guides that are required to follow the tutorial. 74 | 75 | Use the following command to clone the repository 76 | 77 | ```bash 78 | git clone https://github.com/anubhavmishra/consul-dns-for-kubernetes.git 79 | ``` 80 | 81 | The tutorial assumes that you are in `consul-dns-for-kubernetes` directory throughout the tutorial. 82 | 83 | Use the following command to go to tutorial directory 84 | 85 | ```bash 86 | cd consul-dns-for-kubernetes 87 | ``` 88 | 89 | ## Bootstrap Consul Servers 90 | 91 | This tutorial assumes that the consul cluster is not running on Kubernetes. If you want to run a consul cluster on Kubernetes, follow the [consul-on-kubernetes](https://github.com/kelseyhightower/consul-on-kubernetes) by [Kelsey Hightower](https://github.com/kelseyhightower/). 92 | 93 | In this tutorial, we will create a 3 node Consul cluster. 94 | 95 | Create Consul Servers 96 | 97 | ```bash 98 | gcloud compute instances create consul-1 consul-2 consul-3 \ 99 | --image-project ubuntu-os-cloud \ 100 | --image-family ubuntu-1604-lts \ 101 | --boot-disk-size 250GB \ 102 | --machine-type n1-standard-1 \ 103 | --can-ip-forward \ 104 | --scopes default,compute-ro \ 105 | --tags "consul-server" \ 106 | --metadata-from-file startup-script=scripts/bootstrap-consul-server.sh 107 | ``` 108 | 109 | ```bash 110 | Created [https://www.googleapis.com/compute/v1/projects/hc-da-test/zones/us-west1-b/instances/consul-3]. 111 | Created [https://www.googleapis.com/compute/v1/projects/hc-da-test/zones/us-west1-b/instances/consul-1]. 112 | Created [https://www.googleapis.com/compute/v1/projects/hc-da-test/zones/us-west1-b/instances/consul-2]. 113 | NAME ZONE MACHINE_TYPE PREEMPTIBLE INTERNAL_IP EXTERNAL_IP STATUS 114 | consul-3 us-west1-b n1-standard-1 10.138.0.5 35.199.174.16 RUNNING 115 | consul-1 us-west1-b n1-standard-1 10.138.0.7 35.197.101.115 RUNNING 116 | consul-2 us-west1-b n1-standard-1 10.138.0.6 35.230.9.80 RUNNING 117 | ``` 118 | 119 | *The Consul nodes might take a few moments to join the cluster.* 120 | 121 | Validate Consul cluster 122 | 123 | ```bash 124 | gcloud compute ssh consul-1 125 | ``` 126 | 127 | ```bash 128 | username@consul-1:~$ consul members 129 | Node Address Status Type Build Protocol DC Segment 130 | consul-1 10.138.0.7:8301 alive server 1.0.5 2 dc1 131 | consul-2 10.138.0.6:8301 alive server 1.0.5 2 dc1 132 | consul-3 10.138.0.5:8301 alive server 1.0.5 2 dc1 133 | ``` 134 | 135 | ```bash 136 | username@consul-1:~$ exit 137 | ``` 138 | 139 | Logout of `consul-1` 140 | 141 | ```bash 142 | logout 143 | Connection to 35.197.101.115 closed. 144 | ``` 145 | 146 | Create consul deployment 147 | 148 | The consul deployment starts two consul agents in client mode inside the Kubernetes cluster. In this tutorial, we will use Consul's [cloud auto join](https://www.consul.io/docs/agent/options.html#cloud-auto-joining) feature to discover Consul servers running outside the Kubernetes cluster. 149 | 150 | ```bash 151 | apiVersion: apps/v1beta2 152 | kind: Deployment 153 | metadata: 154 | name: consul 155 | .... 156 | args: 157 | - "agent" 158 | - "-advertise=$(POD_IP)" 159 | - "-bind=0.0.0.0" 160 | - "-client=0.0.0.0" 161 | - "-data-dir=/var/consul" 162 | - "-datacenter=dc1" 163 | - "-retry-join=provider=gce tag_value=consul-server" 164 | .... 165 | ``` 166 | 167 | Notice we are using `-retry-join=provider=gce tag_value=consul-server` to use tags to discover the Consul servers. 168 | 169 | ```bash 170 | kubectl apply -f deployments/consul.yaml 171 | deployment "consul" created 172 | ``` 173 | 174 | This will create a deployment with two replicas of the Consul agent running in client mode. 175 | 176 | Check consul deployment, list pods for the deployment 177 | 178 | ```bash 179 | kubectl get pods --namespace=kube-system | grep consul 180 | ``` 181 | 182 | ```bash 183 | consul-8f858fd45-7m5b8 1/1 Running 0 35s 184 | consul-8f858fd45-sknrk 1/1 Running 0 36s 185 | ``` 186 | 187 | Create consul service 188 | 189 | ```bash 190 | kubectl apply -f services/consul-dns.yaml 191 | service "consul-dns" created 192 | ``` 193 | 194 | Check consul service 195 | 196 | ```bash 197 | kubectl describe service consul-dns --namespace=kube-system 198 | ``` 199 | 200 | ```bash 201 | Name: consul-dns 202 | Namespace: kube-system 203 | Labels: name=consul-dns 204 | Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"name":"consul-dns"},"name":"consul-dns","namespace":"kube-system"},"spec":{... 205 | Selector: name=consul 206 | Type: ClusterIP 207 | IP: 10.35.250.89 208 | Port: dns-tcp 53/TCP 209 | TargetPort: dns-tcp/TCP 210 | Endpoints: 10.32.0.41:8600,10.32.2.41:8600 211 | Port: dns-udp 53/UDP 212 | TargetPort: dns-udp/UDP 213 | Endpoints: 10.32.0.41:8600,10.32.2.41:8600 214 | Session Affinity: None 215 | Events: 216 | ``` 217 | 218 | The `consul-dns` service exposes the Consul DNS interface to the pods running in the Kubernetes cluster. 219 | 220 | Create kube-dns configmap 221 | 222 | ```bash 223 | cat < 263 | ``` 264 | 265 | Test consul dns from inside kubernetes 266 | 267 | THe one-time job does a DNS lookup for the `consul` service running on the Consul servers from inside the Kubernetes cluster. This helps validate that services registered in Consul can be discovered using DNS based discovery. 268 | 269 | ```bash 270 | kubectl apply -f job/dns.yaml 271 | ``` 272 | 273 | Get the pod name for dns 274 | 275 | ```bash 276 | kubectl get pods --show-all | grep dns 277 | ``` 278 | 279 | ```bash 280 | dns-hqglg 0/1 Completed 0 20s 281 | ``` 282 | 283 | Get logs from the job 284 | 285 | ```bash 286 | kubectl logs dns-hqglg 287 | ``` 288 | 289 | Confirm `consul.service.consul` lookup is successful 290 | 291 | ```bash 292 | 293 | ; <<>> DiG 9.11.2-P1 <<>> consul.service.consul 294 | ;; global options: +cmd 295 | ;; Got answer: 296 | ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43374 297 | ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1 298 | 299 | ;; OPT PSEUDOSECTION: 300 | ; EDNS: version: 0, flags:; udp: 4096 301 | ;; QUESTION SECTION: 302 | ;consul.service.consul. IN A 303 | 304 | ;; ANSWER SECTION: 305 | consul.service.consul. 0 IN A 10.138.0.5 306 | consul.service.consul. 0 IN A 10.138.0.7 307 | consul.service.consul. 0 IN A 10.138.0.6 308 | 309 | ;; Query time: 19 msec 310 | ;; SERVER: 10.35.240.10#53(10.35.240.10) 311 | ;; WHEN: Sat Mar 10 06:57:44 UTC 2018 312 | ;; MSG SIZE rcvd: 98 313 | 314 | ``` 315 | 316 | Now any pod running in Kubernetes can use `{service_name}.service.consul` DNS name to lookup services registered in Consul. -------------------------------------------------------------------------------- /configmaps/kube-dns.yaml: -------------------------------------------------------------------------------- 1 | apiVersion: v1 2 | kind: ConfigMap 3 | metadata: 4 | labels: 5 | addonmanager.kubernetes.io/mode: EnsureExists 6 | name: kube-dns 7 | namespace: kube-system 8 | data: 9 | stubDomains: | 10 | {"consul": ["{CONSUL_SERVICE_IP}"]} -------------------------------------------------------------------------------- /deployments/consul.yaml: -------------------------------------------------------------------------------- 1 | apiVersion: apps/v1beta2 2 | kind: Deployment 3 | metadata: 4 | name: consul 5 | namespace: kube-system 6 | labels: 7 | name: consul 8 | spec: 9 | replicas: 2 10 | selector: 11 | matchLabels: 12 | name: consul 13 | template: 14 | metadata: 15 | labels: 16 | name: consul 17 | spec: 18 | containers: 19 | - name: consul 20 | image: "consul:1.0.6" 21 | env: 22 | - name: POD_IP 23 | valueFrom: 24 | fieldRef: 25 | fieldPath: status.podIP 26 | args: 27 | - "agent" 28 | - "-advertise=$(POD_IP)" 29 | - "-bind=0.0.0.0" 30 | - "-client=0.0.0.0" 31 | - "-data-dir=/var/consul" 32 | - "-datacenter=dc1" 33 | - "-retry-join=provider=gce tag_value=consul-server" 34 | lifecycle: 35 | preStop: 36 | exec: 37 | command: 38 | - /bin/sh 39 | - -c 40 | - consul leave 41 | ports: 42 | - name: dns-tcp 43 | containerPort: 8600 44 | protocol: "TCP" 45 | - name: dns-udp 46 | containerPort: 8600 47 | protocol: "UDP" 48 | - name: http 49 | containerPort: 8500 50 | protocol: "TCP" 51 | - name: https 52 | containerPort: 8443 53 | protocol: "TCP" 54 | - name: serf-lan-tcp 55 | containerPort: 8301 56 | protocol: "TCP" 57 | - name: serf-lan-udp 58 | containerPort: 8301 59 | protocol: "UDP" 60 | volumeMounts: 61 | - name: consul-data 62 | mountPath: /var/consul 63 | terminationGracePeriodSeconds: 10 64 | volumes: 65 | - name: consul-data 66 | emptyDir: {} -------------------------------------------------------------------------------- /job/dns.yaml: -------------------------------------------------------------------------------- 1 | apiVersion: batch/v1 2 | kind: Job 3 | metadata: 4 | name: dns 5 | spec: 6 | template: 7 | spec: 8 | containers: 9 | - name: dns 10 | image: anubhavmishra/tiny-tools 11 | command: ["dig", "consul.service.consul"] 12 | restartPolicy: Never 13 | backoffLimit: 4 14 | -------------------------------------------------------------------------------- /scripts/bootstrap-consul-server.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | export IP_ADDRESS=$(curl -s -H "Metadata-Flavor: Google" \ 4 | http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip) 5 | 6 | export PROJECT_NAME=$(curl -s -H "Metadata-Flavor: Google" \ 7 | http://metadata.google.internal/computeMetadata/v1/project/project-id) 8 | 9 | apt-get update 10 | # Install unzip and dnsmasq 11 | apt-get install -y unzip dnsmasq 12 | 13 | ## Setup consul 14 | mkdir -p /var/lib/consul 15 | 16 | wget https://releases.hashicorp.com/consul/1.0.5/consul_1.0.5_linux_amd64.zip 17 | unzip consul_1.0.5_linux_amd64.zip 18 | mv consul /usr/local/bin/consul 19 | rm consul_1.0.5_linux_amd64.zip 20 | 21 | cat > consul.service <<'EOF' 22 | [Unit] 23 | Description=consul 24 | Documentation=https://consul.io/docs/ 25 | 26 | [Service] 27 | ExecStart=/usr/local/bin/consul agent \ 28 | -advertise=ADVERTISE_ADDR \ 29 | -bind=0.0.0.0 \ 30 | -bootstrap-expect 3 \ 31 | -retry-join "provider=gce project_name=PROJECT_NAME tag_value=consul-server" \ 32 | -client=0.0.0.0 \ 33 | -data-dir=/var/lib/consul \ 34 | -server \ 35 | -ui 36 | 37 | ExecReload=/bin/kill -HUP $MAINPID 38 | LimitNOFILE=65536 39 | 40 | [Install] 41 | WantedBy=multi-user.target 42 | EOF 43 | 44 | sed -i "s/ADVERTISE_ADDR/${IP_ADDRESS}/" consul.service 45 | sed -i "s/PROJECT_NAME/${PROJECT_NAME}/" consul.service 46 | mv consul.service /etc/systemd/system/consul.service 47 | systemctl enable consul 48 | systemctl start consul 49 | 50 | # Configure dnsmasq 51 | mkdir -p /etc/dnsmasq.d 52 | cat > /etc/dnsmasq.d/10-consul <<'EOF' 53 | server=/consul/127.0.0.1#8600 54 | EOF 55 | 56 | systemctl enable dnsmasq 57 | systemctl start dnsmasq 58 | # Force restart for adding consul dns 59 | systemctl restart dnsmasq 60 | -------------------------------------------------------------------------------- /services/consul-dns.yaml: -------------------------------------------------------------------------------- 1 | apiVersion: v1 2 | kind: Service 3 | metadata: 4 | name: consul-dns 5 | namespace: kube-system 6 | labels: 7 | name: consul-dns 8 | spec: 9 | ports: 10 | - name: dns-tcp 11 | port: 53 12 | protocol: "TCP" 13 | targetPort: dns-tcp 14 | - name: dns-udp 15 | port: 53 16 | protocol: "UDP" 17 | targetPort: dns-udp 18 | selector: 19 | name: consul --------------------------------------------------------------------------------