Add Image as Environment Variable

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: add-image-as-env-var
  annotations:
    pod-policies.kyverno.io/autogen-controllers: none
    policies.kyverno.io/title: Add Image as Environment Variable
    policies.kyverno.io/category: Other
    policies.kyverno.io/severity: medium
    kyverno.io/kyverno-version: 1.10.0-alpha.2
    kyverno.io/kubernetes-version: "1.26"
    policies.kyverno.io/subject: Pod
    policies.kyverno.io/description: The Kubernetes downward API only has the ability to express so many options as environment variables. The image consumed in a Pod is commonly needed to make the application aware of some logic it must take. This policy takes the value of the `image` field and adds it as an environment variable to Pods.
spec:
  rules:
    - name: pod-containers-inject-image
      match:
        any:
          - resources:
              kinds:
                - Pod
      mutate:
        foreach:
          - list: request.object.spec.containers[]
            patchesJson6902: |-
              - op: add
                path: /spec/containers/{{elementIndex}}/env/-
                value:
                  name: K8S_IMAGE
                  value: "{{ element.image }}"