Kubernetes Deployments and Init Containers

Question

I learned recently that Kubernetes has a feature called Init Containers. Awesome, because I can use this feature to wait for my postgres service and create/migrate the database

Answer 1

You probably want to use readiness probes instead of init containers for this use case. Check out this link and a blog. Also note that a deployment will not send traffic to a pod that is not reported ready - If that was your worry.

This is a well known pattern and a readiness probe in the web server would simply check the DB endpoint / data availability before reporting ready. This is a simple solution as opposed to the complexity of an extra init container and has the advantage of detecting DB outages correctly as well.