Canary

Blue-Green

Best Practices

• Its bad practice to just include a kubectl apply command, because sometimes the deployment can fail or crash, so its best to add a rollout status in the steps. Example:

  • k8s-deployment.sh

    #!/bin/bash
    
    sed -i "s#replace#${imageName}#g" k8s_deployment_service.yaml
    kubectl -n default get deployment ${deploymentName} > /dev/null
    
    if [[ $? -ne 0 ]]; then
        echo "Deployment ${deploymentName} does not exist"
        kubectl -n default apply -f k8s_deployment_service.yaml
    else
        echo "Deployment exists, updating"
        echo "image name: ${imageName}"
        kubectl -n default set image deploy ${deploymentName} ${containerName}=${imageName} --record=true
    fi
    

  • k8s-deployment-rollout-status.sh

    #!/bin/bash
    
    sleep 60s
    
    # maximum timeout to consider a deployment is successful is 15s
    if [[ $(kubectl -n default rollout status deploy ${deploymentName} --timeout 15s) != *"successfully rolled out"* ]];
    then
        echo "Deployment $deploymentName} Rollout has failed"
        kubectl -n default rollout undo deploy ${deploymentName}
        exit 1;
    else
        echo "Deployment ${deploymentName rollout is successful"
    fi
    

  • Then include them as steps in the pipeline script of your CI/CD