Change the "imagePullPolicy" to allow Air-Gap install of contour operator

[sbenhazez]

Use case :
Air-Gap install of contour operator

Contour resources used for test :
https://raw.githubusercontent.com/projectcontour/contour-operator/main/examples/operator/operator.yaml
https://raw.githubusercontent.com/projectcontour/contour-operator/main/examples/gateway/gateway-nodeport.yaml

Images loaded in air-gap environment:

• ghcr.io/projectcontour/contour-operator:main
• ghcr.io/projectcontour/contour:main
• docker.io/envoyproxy/envoy:v1.22.0
• gcr.io/kubebuilder/kube-rbac-proxy:v0.8.0

Problem for creating pod/contour-certgen-main :

Events:
  Type    Reason   Age                     From     Message
  ----    ------   ----                    ----     -------
  Normal  BackOff  4m30s (x728 over 169m)  kubelet  Back-off pulling image "ghcr.io/projectcontour/contour:main"

Image pull policy in contour object:
The source of problem is that the object job.go force the policy to PullAlways :
- daemonset.go : ImagePullPolicy: corev1.PullIfNotPresent,
- deployment.go : ImagePullPolicy: corev1.PullIfNotPresent,
- job.go: ImagePullPolicy : corev1.PullAlways

Environment:

• Software version:
• Kubernetes version: (use kubectl version): v1.23.6
• Kubernetes installer & version: K3s (v1.23.6+k3s1 )
• Cloud provider or hardware configuration:
• OS (e.g. from /etc/os-release): Debian 10

[skriss]

We should consider leaving the image pull policy as Always on the main branch, for any ghcr.io/projectcontour/contour:main images, but changing it to IfNotPresent for the release tags, via https://github.com/projectcontour/contour-operator/blob/main/hack/release/make-release-tag.sh.