Review app deployment fails because unicorn image does not exist in registry

Observed in jobs:

Example unicorn pod events:

Events:
  Type     Reason     Age                   From                                                          Message
  ----     ------     ----                  ----                                                          -------
  Normal   Scheduled  52m                   default-scheduler                                             Successfully assigned review-apps-ee/review-212335-upg-ebtufe-unicorn-58c769c78f-cnkq9 to gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4
  Normal   Pulling    52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Pulling image "registry.gitlab.com/gitlab-org/build/cng/alpine-certificates:20171114-r3"
  Normal   Pulled     52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Successfully pulled image "registry.gitlab.com/gitlab-org/build/cng/alpine-certificates:20171114-r3"
  Normal   Created    52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Created container certificates
  Normal   Started    52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Started container certificates
  Normal   Pulling    52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Pulling image "busybox:latest"
  Normal   Pulled     52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Successfully pulled image "busybox:latest"
  Normal   Created    52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Created container configure
  Normal   Started    52m                   kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Started container configure
  Normal   Pulling    51m (x3 over 52m)     kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Pulling image "registry.gitlab.com/gitlab-org/build/cng-mirror/gitlab-unicorn-ee:212335-upgrade-review-apps-chart-version-to-3-2-0"
  Warning  Failed     51m (x3 over 52m)     kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Failed to pull image "registry.gitlab.com/gitlab-org/build/cng-mirror/gitlab-unicorn-ee:212335-upgrade-review-apps-chart-version-to-3-2-0": rpc error: code = Unknown desc = failed to resolve image "registry.gitlab.com/gitlab-org/build/cng-mirror/gitlab-unicorn-ee:212335-upgrade-review-apps-chart-version-to-3-2-0": no available registry endpoint: registry.gitlab.com/gitlab-org/build/cng-mirror/gitlab-unicorn-ee:212335-upgrade-review-apps-chart-version-to-3-2-0 not found
  Warning  Failed     51m (x3 over 52m)     kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Error: ErrImagePull
  Warning  Failed     7m (x197 over 52m)    kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Error: ImagePullBackOff
  Normal   BackOff    2m5s (x218 over 52m)  kubelet, gke-review-apps-ee-e2-8cpu-8gb-preemp-a6a291bb-8ds4  Back-off pulling image "registry.gitlab.com/gitlab-org/build/cng-mirror/gitlab-unicorn-ee:212335-upgrade-review-apps-chart-version-to-3-2-0"

The image doesn't exist in registry.

docker pull registry.gitlab.com/gitlab-org/build/cng-mirror/gitlab-unicorn-ee:212335-upgrade-review-apps-chart-version-to-3-2-0
Error response from daemon: manifest for registry.gitlab.com/gitlab-org/build/cng-mirror/gitlab-unicorn-ee:212335-upgrade-review-apps-chart-version-to-3-2-0 not found: manifest unknown: manifest unknown

/cc @gl-quality/eng-prod

Edited by Albert Salim