deploymentpatch

Using kubetruth to trigger reload/restart of pre-existing app

This example uses kubetruth to patch a kubernetes deployment whenever dependent parameters change

Setup CloudTruth Credentials

Login to CloudTruth, and create an api key, then add it to your environment

export CLOUDTRUTH_API_KEY=your_api_key

(Optional) Setup minikube to test locally

minikube start

Deploy a pre-existing application

kubectl apply -f examples/deploymentpatch/deployment.yaml

Check service is up, note environment vars

kubectl describe deployment deploypatchtest
kubectl get deployment/deploypatchtest -o yaml | grep -A2 envFrom:
kubectl exec deployment/deploypatchtest -- printenv | grep MY_ENV

Setup a project to configure the environment

cloudtruth projects set deploypatchtest

cloudtruth --project deploypatchtest parameter set --value "Hello from patch" MY_ENV_HELLO
cloudtruth --project deploypatchtest parameter set --value "Goodbye from patch" MY_ENV_GOODBYE

Setup kubetruth to create a configmap and patch pre-existing deployment resource for that project

Install kubetruth with the settings that enable deployment patching:

helm install --values examples/deploymentpatch/values.yaml --set appSettings.apiKey=$CLOUDTRUTH_API_KEY kubetruth cloudtruth/kubetruth

Check kubetruth is up

kubectl describe deployment kubetruth
kubectl logs deployment/kubetruth

Note that you can ignore the warning:

Skipping 'default:Deployment:deploypatchtest' as it doesn't have a label indicating it is under kubetruth management

This is expected as kubetruth won't touch any resources that it didn't create unless they are labelled like we do in the next step.

Allow kubetruth to patch existing deployment

kubectl label deployment/deploypatchtest app.kubernetes.io/managed-by=kubetruth

Wake kubetruth from polling sleep

kubectl exec deployment/kubetruth -- wakeup

Check service environment vars

kubectl get deployment/deploypatchtest -o yaml | grep -A2 envFrom:
kubectl exec deployment/deploypatchtest -- printenv | grep MY_ENV

Trigger an update

cloudtruth --project deploypatchtest parameter set --value "A New Hello from patch" MY_ENV_HELLO
kubectl exec deployment/kubetruth -- wakeup

Check service environment vars

kubectl get deployment/deploypatchtest -o yaml | grep -A2 envFrom:
kubectl exec deployment/deploypatchtest -- printenv | grep MY_ENV