As word init describe, init containers are run before application containers run.

In some scenarios, we have to verify or perform certain action before starting the app container, like installing utilities or run a setup script etc. at that time, we can leverage the init container.

Some facts about init containers.

• We can run multiple init containers before the app container.

• init containers always run to completion.

• Each init contianer must complete successfully before the next one starts.

Let's do some hands-on with the init container.

In previous labs, we have created ruby on rails crud app , we are going to add an init container in that same config,

 initContainers:
        - name: init-db
          image: busybox:1.31
          command: ['sh', '-c', 'while ! nc -z postgres 5432; do sleep 1; printf "-"; done; echo -e "  >> Postgres DB Server has started";']

What if the application started serving the request and database service is not up and running? nightmare right?

to overcome this, we can use the init container as the above config. as you can see until the DB is not started init container keeps running and will not allow application container to start.

• Reference: https://kubernetes.io/docs/concepts/workloads/pods/init-containers/

• Reference: https://github.com/m3pratik/31daysofEKS/

Made with ❤️ by Pratikkumar Panchal. github.com/m3pratik/31daysofEKS