How to restart pod in OpenShift?

Question

I updated a file (for debug output) in a running pod, but it isn't getting recognized. I was going to restart the pod to get it to take but I only see oc stop and not oc start or oc restart. How would I force a refresh of files in the pod?

I am thinking maybe it is a Ruby thing (like opcache in PHP). But figured a restart of the pod would handle it. Just can't figure out how to restart a pod.

Answer 1

You need to do your changes in the deployment config but not in the pod. Because OpenShift treats pods as largely immutable; changes cannot be made to a pod definition while it is running. https://docs.openshift.com/enterprise/3.0/architecture/core_concepts/pods_and_services.html#pods

If you make some changes in deployment config and save them, pod will restart and and your changes will take effect:

oc edit dc "deploy-config-example"

If you change something in volumes or configmaps you need to delete pod for his restart:

oc delete pod "name-of-your-pod"

And pod will restart. Or better still trigger a new deployment by running:

oc rollout latest "deploy-config-example"

Using oc rollout is better because it will re-deploy all pods if you have a scaled application, and you don't need to identify each pod and delete it.

Answer 2

You can scale deployments down (to zero) and then up again:

oc get deployments -n <your project> -o wide

oc get pods -n <your project> -o wide

oc scale --replicas=0 deployment/<your deployment> -n <your project>

oc scale --replicas=1 deployment/<your deployment> -n <your project>

watch oc get pods -n <your project> # wait until your deployment is up again