Multi-container Pods

A pod can have one or more containers running in it. If it runs multiple containers, there are primarily three different patterns:

1. Co-located
2. Init
3. Sidecar

Co-located

When both containers are dependent on each other and both continue running for the duration of the pod’s lifecycle.

Init

Init containers are run before the app container is started. They run, do their thing and then the main container is started.

Sidecar

This starts before the main app container and continues to run. This is how they are different from init containers. Sidecar containers may be used for monitoring, for example.