Helmfile install ingress

Installs ingress (using helmfile)

Also supports custom values.yaml file as well

Part of gitlab-org/gitlab#7983 (closed)

Testing

See also pipeline for this MR

Without custom .gitlab/managed-apps/ingress/values.yaml file

https://gitlab.com/gitlab-org/cluster-integration/cluster-applications/-/jobs/338571650

With custom .gitlab/managed-apps/ingress/values.yaml file

https://gitlab.com/gitlab-org/cluster-integration/cluster-applications/-/jobs/339046804

.gitlab-ci.yml

@@ -28,6 +28,9 @@ install-ingress:
   extends: .cluster-integration
   variables:
     TILLER_NAMESPACE: gitlab-managed-apps
-    INGRESS_VALUES_FILE: .gitlab/managed-apps/ingress/values.yaml
   script:
+    - export INGRESS_VALUES_FILE=$(realpath .gitlab/managed-apps/ingress/values.yaml)
+    - ls
+    - echo "$INGRESS_VALUES_FILE"
+    - cat $INGRESS_VALUES_FILE
     - gitlab-managed-apps /usr/local/share/gitlab-managed-apps/helmfile.yaml