├── kubernetes ├── service.yaml ├── blue-deploy.yaml └── green-deploy.yaml ├── CONTRIBUTING.md ├── bin └── bg-deploy.sh ├── README.md └── LICENSE /kubernetes/service.yaml: -------------------------------------------------------------------------------- 1 | # Copyright 2017 Google Inc. 2 | # 3 | # Licensed under the Apache License, Version 2.0 (the "License"); 4 | # you may not use this file except in compliance with the License. 5 | # You may obtain a copy of the License at 6 | # 7 | # http://www.apache.org/licenses/LICENSE-2.0 8 | # 9 | # Unless required by applicable law or agreed to in writing, software 10 | # distributed under the License is distributed on an "AS IS" BASIS, 11 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 | # See the License for the specific language governing permissions and 13 | # limitations under the License. 14 | 15 | apiVersion: v1 16 | kind: Service 17 | metadata: 18 | name: nginx 19 | labels: 20 | name: nginx 21 | spec: 22 | ports: 23 | - name: http 24 | port: 80 25 | targetPort: 80 26 | selector: 27 | name: nginx 28 | version: "1.10" 29 | type: LoadBalancer 30 | -------------------------------------------------------------------------------- /CONTRIBUTING.md: -------------------------------------------------------------------------------- 1 | # How to Contribute 2 | 3 | We'd love to accept your patches and contributions to this project. There are 4 | just a few small guidelines you need to follow. 5 | 6 | ## Contributor License Agreement 7 | 8 | Contributions to this project must be accompanied by a Contributor License 9 | Agreement. You (or your employer) retain the copyright to your contribution, 10 | this simply gives us permission to use and redistribute your contributions as 11 | part of the project. Head over to to see 12 | your current agreements on file or to sign a new one. 13 | 14 | You generally only need to submit a CLA once, so if you've already submitted one 15 | (even if it was for a different project), you probably don't need to do it 16 | again. 17 | 18 | ## Code reviews 19 | 20 | All submissions, including submissions by project members, require review. We 21 | use GitHub pull requests for this purpose. Consult 22 | [GitHub Help](https://help.github.com/articles/about-pull-requests/) for more 23 | information on using pull requests. 24 | -------------------------------------------------------------------------------- /kubernetes/blue-deploy.yaml: -------------------------------------------------------------------------------- 1 | # Copyright 2017 Google Inc. 2 | # 3 | # Licensed under the Apache License, Version 2.0 (the "License"); 4 | # you may not use this file except in compliance with the License. 5 | # You may obtain a copy of the License at 6 | # 7 | # http://www.apache.org/licenses/LICENSE-2.0 8 | # 9 | # Unless required by applicable law or agreed to in writing, software 10 | # distributed under the License is distributed on an "AS IS" BASIS, 11 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 | # See the License for the specific language governing permissions and 13 | # limitations under the License. 14 | 15 | apiVersion: extensions/v1beta1 16 | kind: Deployment 17 | metadata: 18 | name: nginx-1.10 19 | spec: 20 | replicas: 3 21 | template: 22 | metadata: 23 | labels: 24 | name: nginx 25 | version: "1.10" 26 | spec: 27 | containers: 28 | - name: nginx 29 | image: nginx:1.10 30 | ports: 31 | - name: http 32 | containerPort: 80 33 | -------------------------------------------------------------------------------- /kubernetes/green-deploy.yaml: -------------------------------------------------------------------------------- 1 | # Copyright 2017 Google Inc. 2 | # 3 | # Licensed under the Apache License, Version 2.0 (the "License"); 4 | # you may not use this file except in compliance with the License. 5 | # You may obtain a copy of the License at 6 | # 7 | # http://www.apache.org/licenses/LICENSE-2.0 8 | # 9 | # Unless required by applicable law or agreed to in writing, software 10 | # distributed under the License is distributed on an "AS IS" BASIS, 11 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 | # See the License for the specific language governing permissions and 13 | # limitations under the License. 14 | 15 | apiVersion: extensions/v1beta1 16 | kind: Deployment 17 | metadata: 18 | name: nginx-1.11 19 | spec: 20 | replicas: 3 21 | template: 22 | metadata: 23 | labels: 24 | name: nginx 25 | version: "1.11" 26 | spec: 27 | containers: 28 | - name: nginx 29 | image: nginx:1.11 30 | ports: 31 | - name: http 32 | containerPort: 80 33 | -------------------------------------------------------------------------------- /bin/bg-deploy.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash -eu 2 | # 3 | # Copyright 2017 Google Inc. 4 | # 5 | # Licensed under the Apache License, Version 2.0 (the "License"); 6 | # you may not use this file except in compliance with the License. 7 | # You may obtain a copy of the License at 8 | # 9 | # http://www.apache.org/licenses/LICENSE-2.0 10 | # 11 | # Unless required by applicable law or agreed to in writing, software 12 | # distributed under the License is distributed on an "AS IS" BASIS, 13 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 | # See the License for the specific language governing permissions and 15 | # limitations under the License. 16 | 17 | #!/bin/bash 18 | 19 | # bg-deploy.sh 20 | # Deployment name should be - 21 | 22 | DEPLOYMENTNAME=$1-$2 23 | SERVICE=$1 24 | VERSION=$2 25 | DEPLOYMENTFILE=$3 26 | 27 | kubectl apply -f $DEPLOYMENTFILE 28 | 29 | # Wait until the Deployment is ready by checking the MinimumReplicasAvailable condition. 30 | READY=$(kubectl get deploy $DEPLOYMENTNAME -o json | jq '.status.conditions[] | select(.reason == "MinimumReplicasAvailable") | .status' | tr -d '"') 31 | while [[ "$READY" != "True" ]]; do 32 | READY=$(kubectl get deploy $DEPLOYMENTNAME -o json | jq '.status.conditions[] | select(.reason == "MinimumReplicasAvailable") | .status' | tr -d '"') 33 | sleep 5 34 | done 35 | 36 | # Update the service selector with the new version 37 | kubectl patch svc $SERVICE -p "{\"spec\":{\"selector\": {\"name\": \"${SERVICE}\", \"version\": \"${VERSION}\"}}}" 38 | 39 | echo "Done." 40 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Kubernetes Blue/Green Deployment Tutorial 2 | 3 | This is a simple tutorial on how to do [Blue/Green Deployment](https://martinfowler.com/bliki/BlueGreenDeployment.html) on Kubernetes. 4 | 5 | ## Prerequisites 6 | 7 | Any Kubernetes cluster 1.3+ should work. Creating a cluster on [GKE](https://cloud.google.com/container-engine/) is pretty easy. 8 | 9 | ``` 10 | gcloud container clusters create bluegreen 11 | ``` 12 | 13 | ## Setup 14 | 15 | The blue Deployment is the version that is deployed live in production. It can be accessed externally by end users via a Service with type=LoadBalancer 16 | 17 | ### Create the Blue Deployment 18 | 19 | The Deployment will start up a few nginx containers as the application. The Deployment has a `name` and `version` label. This is significant as the Service will use these labels to switch to the green version later. 20 | 21 | [embedmd]:# (kubernetes/blue-deploy.yaml yaml) 22 | ```yaml 23 | apiVersion: extensions/v1beta1 24 | kind: Deployment 25 | metadata: 26 | name: nginx-1.10 27 | spec: 28 | replicas: 3 29 | template: 30 | metadata: 31 | labels: 32 | name: nginx 33 | version: "1.10" 34 | spec: 35 | containers: 36 | - name: nginx 37 | image: nginx:1.10 38 | ports: 39 | - name: http 40 | containerPort: 80 41 | ``` 42 | 43 | Create the Blue Deployment: 44 | 45 | ``` 46 | $ kubectl apply -f kubernetes/blue-deploy.yaml 47 | ``` 48 | 49 | The service is of type=LoadBalancer so it can be accessed via a Network Load Balancer on GCP. It uses the `name` and `version` labels specified in the Deployment to select the pods for the service. 50 | 51 | [embedmd]:# (kubernetes/service.yaml yaml) 52 | ```yaml 53 | apiVersion: v1 54 | kind: Service 55 | metadata: 56 | name: nginx 57 | labels: 58 | name: nginx 59 | spec: 60 | ports: 61 | - name: http 62 | port: 80 63 | targetPort: 80 64 | selector: 65 | name: nginx 66 | version: "1.10" 67 | type: LoadBalancer 68 | ``` 69 | 70 | Create the Service: 71 | 72 | ``` 73 | $ kubectl apply -f kubernetes/service.yaml 74 | ``` 75 | 76 | ### Test the Blue Deployment 77 | 78 | The currently deployed version can be tested in a separate window by polling the server. This will print the current deployed nginx version. 79 | 80 | ``` 81 | $ EXTERNAL_IP=$(kubectl get svc nginx -o jsonpath="{.status.loadBalancer.ingress[*].ip}") 82 | $ while true; do curl -s http://$EXTERNAL_IP/version | grep nginx; sleep 0.5; done 83 | ``` 84 | 85 | Now we are ready to deploy a new version. 86 | 87 | ## Update the application 88 | 89 | A new Deployment will be created to update the application and the Service will be updated to point at the new version. This is mostly instantaneous. 90 | 91 | ### Create the Green Deployment 92 | 93 | The Green Deployment is cerated by updating to the next version. An entirely new Deployment will be created with different labels. Note that these labels don't match the Service yet and so requests will not be sent to pods in the Deployment. 94 | 95 | [embedmd]:# (kubernetes/green-deploy.yaml yaml) 96 | ```yaml 97 | apiVersion: extensions/v1beta1 98 | kind: Deployment 99 | metadata: 100 | name: nginx-1.11 101 | spec: 102 | replicas: 3 103 | template: 104 | metadata: 105 | labels: 106 | name: nginx 107 | version: "1.11" 108 | spec: 109 | containers: 110 | - name: nginx 111 | image: nginx:1.11 112 | ports: 113 | - name: http 114 | containerPort: 80 115 | ``` 116 | 117 | You can update the Blue Deployment's file directly or use a tool like `sed`: 118 | 119 | Create the new Deployment: 120 | 121 | ``` 122 | $ sed 's/1\.10/1.11/' kubernetes/blue-deploy.yaml | kubectl apply -f - 123 | ``` 124 | 125 | ### Switch Traffic to the Green Version 126 | 127 | We will update the Service to select pods from the Green Deployment. This will cause new requests to be set to the new pods. 128 | 129 | You can update the file directly or use a tool like `sed`: 130 | 131 | ``` 132 | $ sed 's/1\.10/1.11/' kubernetes/service.yaml 133 | apiVersion: v1 134 | kind: Service 135 | metadata: 136 | name: nginx 137 | labels: 138 | name: nginx 139 | spec: 140 | ports: 141 | - name: http 142 | port: 80 143 | targetPort: 80 144 | selector: 145 | name: nginx 146 | version: "1.11" 147 | type: LoadBalancer 148 | ``` 149 | 150 | Update the Service: 151 | 152 | ``` 153 | sed 's/1\.10/1.11/' kubernetes/service.yaml | kubectl apply -f - 154 | ``` 155 | 156 | ### Test the New Version 157 | 158 | At this point traffic should be sent to the Green version and the output of our test loop should show "nginx/1.11.X". However, in a production environment, the Blue version may have some long running requests so it may take some time before the requests are fully drained. That means that some time should be given before deleting the old Blue Deployment. 159 | 160 | ## Automating Blue/Green Deployments 161 | 162 | While ideally Blue/Green Deployments would be implemented server side, one way to automate them is on the client-side using scripts. This very simple bash script creates the new Deployment and waits for it to become ready before updating the Service's selector. 163 | 164 | 165 | [embedmd]:# (bin/bg-deploy.sh bash) 166 | ```bash 167 | #!/bin/bash 168 | 169 | # bg-deploy.sh 170 | # Deployment name should be - 171 | 172 | DEPLOYMENTNAME=$1-$2 173 | SERVICE=$1 174 | VERSION=$2 175 | DEPLOYMENTFILE=$3 176 | 177 | kubectl apply -f $DEPLOYMENTFILE 178 | 179 | # Wait until the Deployment is ready by checking the MinimumReplicasAvailable condition. 180 | READY=$(kubectl get deploy $DEPLOYMENTNAME -o json | jq '.status.conditions[] | select(.reason == "MinimumReplicasAvailable") | .status' | tr -d '"') 181 | while [[ "$READY" != "True" ]]; do 182 | READY=$(kubectl get deploy $DEPLOYMENTNAME -o json | jq '.status.conditions[] | select(.reason == "MinimumReplicasAvailable") | .status' | tr -d '"') 183 | sleep 5 184 | done 185 | 186 | # Update the service selector with the new version 187 | kubectl patch svc $SERVICE -p "{\"spec\":{\"selector\": {\"name\": \"${SERVICE}\", \"version\": \"${VERSION}\"}}}" 188 | 189 | echo "Done." 190 | ``` 191 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | 2 | Apache License 3 | Version 2.0, January 2004 4 | http://www.apache.org/licenses/ 5 | 6 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 7 | 8 | 1. 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