This repository is an example to launch a simple blue/green deployment based on the Istio configuration.

To use this repo you need to clone it to your OS as following:

$ git clone https://github.com/aramirol/istio-example.git

You can use Jenkinsfile file to automate through Jenkins the workflow to do a first deploy or deploy a new version of the app and change the exposed channel.

In the Jenkinsfile, there are three variables that are defined in the early stages and are used to calculate if it is a first run or to apply the new version in the correct color.

NOTE: to use Jenkinsfile you must be sure that your Jenkins is configured to use the kubectl command. If not, you can simulate the Jenkinsfile workflow using manual steps to deploy and force the switch between blue and green app.

Deploy all lab environment included into kubernetes folder using the all.yml:

$ kubectl apply -f kubernetes/all.yml
    namespace/istio-example-bg created
    service/myapp-service created
    gateway.networking.istio.io/myapp-gateway created
    destinationrule.networking.istio.io/myapp-destinationrule created
    virtualservice.networking.istio.io/myapp-virtualservice created
    deployment.apps/myapp-deployment-blue created
    deployment.apps/myapp-deployment-green created

After that, you can deploy a new version of the app and switch the virtualservice to show the default output (you have to use blue/green files alternatively):

$ kubectl apply -f kubernetes/deployment_green.yml
    deployment.apps/myapp-deployment-green configured

$ kubectl apply -f kubernetes/virtualservice_green.yml
    virtualservice.networking.istio.io/myapp-virtualservice configured

After an automatically or manual deploy, you can use the scripts included into scripts folder to test the URLs. Check that the color returned by the URL changes between blue and green:

$ scripts/curl_default.sh
        <h2 class="version name">Green Deployment</h2>
        <h2 class="version name">Green Deployment</h2>
        <h2 class="version name">Green Deployment</h2>
        <h2 class="version name">Blue Deployment</h2>
        <h2 class="version name">Blue Deployment</h2>
        <h2 class="version name">Blue Deployment</h2>

You can also do tests to the offline channel using the test cookie with this script. The return will be the same as default but adding this cookie you will see the offline version. Just the opposite value to the default:

$ scripts/curl_test.sh
        <h2 class="version name">Blue Deployment</h2>
        <h2 class="version name">Blue Deployment</h2>
        <h2 class="version name">Blue Deployment</h2>
        <h2 class="version name">Green Deployment</h2>
        <h2 class="version name">Green Deployment</h2>
        <h2 class="version name">Green Deployment</h2>

You can also use your web browser to navigate to the URL and see the website exposed:

Note: before use these scripts, you must modify the host and the port based in your environment. This fields must be changed into the scripts files.

• The host is the name or IP that you use to access to your (I just use one node). If you have a cluster, you can use the LoadBalancer IP:

  kubectl get nodes -o jsonpath='{.items[0].status.addresses[0].address}'

• The port is the http port exposed throught the ingressgateway in istio-system namespace. If you have a cluster and do not use a nodePort, you must specify the corresponding port type:

  kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].nodePort}'

To destroy all lab and clean the environment, just use the all.yml again:

$ kubectl delete -f kubernetes/all.yml
    namespace "istio-example-bg" deleted
    service "myapp-service" deleted
    gateway.networking.istio.io "myapp-gateway" deleted
    destinationrule.networking.istio.io "myapp-destinationrule" deleted
    virtualservice.networking.istio.io "myapp-virtualservice" deleted
    deployment.apps "myapp-deployment-blue" deleted
    deployment.apps "myapp-deployment-green" deleted

MIT License

See LICENSE to see the full text.