What is the image pull policy for Kubernetes?

The Kubernetes image pull strategy refers to how images are pulled from the image repository when creating or updating a Pod in a Kubernetes cluster.

K8s supports several image pulling strategies, including:

1. Option:
   Default: Always attempt to pull the latest image from the image repository. If the image is not found, an error will be returned.
2. IfNotPresent: First, check if the required image is present on the local node; if it is, use the local image, otherwise attempt to pull it from the image repository.
3. Only use images that already exist on the local node, if the required image is not available locally, an error will be returned.

These strategies can be configured by specifying the imagePullPolicy field in the Pod’s spec. For example:

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
spec:
  containers:
    - name: my-container
      image: my-image
      imagePullPolicy: IfNotPresent

In the example above, the image pulling strategy is set to IfNotPresent, which means that if an image named my-image already exists on the local node, it will be used, otherwise it will attempt to pull from the image repository.