Init Containers

Init containers are the containers that run once during the startup process of a pod. A Pod can have any number of init containers, & they will each run once(in order) to completion.

Practically, the user can use init containers to perform a variety of startup tasks. They can contain & use software and setup scripts that are not needed by the main containers.

Some of the Use cases for Init Containers can:

1. Cause a pod to wait for another Kubernetes resource to be created before finishing startup.
2. Perform sensitive startup steps securely outside of app containers.
3. Populate data into a shared volume at startup.
4. Communicate with another service at startup.

Lets understand the concept of Init containers by means of a demo:

1. Create a pod definition with ‘initContainers’

Delay of 30s given using init container

2. This can be observed that init-pod will start only after a sleep of 30 seconds is executed, after that any other containers can be started.

So, above was a simple demonstration of init containers.
Thank You!