Building Enterprise JavaScript Applications

Using init containers

Using pssh is acceptable, but it's an extra command we need to remember. Ideally, this configuration should be recorded inside stateful-set.yaml, so that the commands only run on nodes that have our Elasticsearch StatefulSet deployed there. Kuberentes provides a special type of Container called Init Containers, which allows us to do just that.

Init Containers are special Containers that run and exit before your "normal" app Containers are initiated. When multiple Init Containers are specified, they run in a sequential order. Also, if the previous Init Container exits with a non-zero exit status, then the next Init Container is not ran and the whole Pod fails.

This allows you to use Init Containers to:

• Poll for the readiness ...