KodeCloud CKA Pause Container

Pause Container¶

Pause containers are responsible for holding the network namespace in a pod.
- They bootstrap the pod to establish all of the cgroups, reservations, and namespaces before its individual containers are created.
- The pause container image is always present, so the pod resource allocation happens instantaneously as containers are created.
IP addresses and other resources are attached to the pause container.
Pause container is always created before the main (app) container.
Pause container is an infrastructure container whose sole purpose is to hold all these namespaces.
If the pause container is deleted, Kubernetes recreates the pod with a new IP address.
Stopping the business application container does not trigger pod recreation, only the container itself is restarted.
- So the IP address remains the same.
We can view the pause containers by going to a worker node and running:
- ctr -n k8s.io c ls

Pause container is like a parent container (PID 1) to all the other containers in the pod and is responsible for killing the zombie processes.

Last updated: 2023-05-30