OpenShift Init Container

External

• https://docs.openshift.com/container-platform/latest/architecture/core_concepts/containers_and_images.html#init-containers

Internal

• OpenShift Pod Concepts
• Kubernetes Init Containers

Overview

Kubernetes Init Containers

Life Cycle

https://kubernetes.io/docs/concepts/workloads/pods/init-containers/#detailed-behavior

Timeout

An init container must finish initializing within ... otherwise it puts the deployment into an error state:

NAME         READY     STATUS    RESTARTS   AGE
a-1-deploy   0/1       Error     0          13m

Resources

https://kubernetes.io/docs/concepts/workloads/pods/init-containers/#resources

Troubleshooting Init Containers

The logs of init containers can be accessed by identifying the name of the init container with:

oc describe po/a-1-0g52b

...
Init Containers:
 b-dependency-checker:
  ...

and then getting the logs from that specific container:

oc logs -f -c b-dependency-checker po/a-1-0g52b

Application Dependency Example

https://github.com/NovaOrdis/playground/tree/master/openshift/applications/service-dependency

TODO: write a step-by-step article.