Fix removed stable repository disrupts Auto Deploy

This commit fixes the removed stable repository problem.

changelogs/unreleased/fix-deprecated-stable-repository-error.yml

+---
+title: Fix auto-deploy-image fetches deprecated stable repository and causes an error
+merge_request: 263778
+author:
+type: fixed

doc/topics/autodevops/index.md

@@ -467,6 +467,35 @@ that works for this problem. Follow these steps to use the tool in Auto DevOps:
 
 1. Continue the deployments as usual.
 
+### Error: error initializing: Looks like "https://kubernetes-charts.storage.googleapis.com" is not a valid chart repository or cannot be reached
+
+As [announced in the official CNCF blogpost](https://www.cncf.io/blog/2020/10/07/important-reminder-for-all-helm-users-stable-incubator-repos-are-deprecated-and-all-images-are-changing-location/),
+the stable Helm chart repository will be deprecated and removed on November 13th, 2020.
+By this reason, you may encounter this problem after the period.
+
+Some GitLab features had had a couple of dependencies on the stable chart as well, but
+we've already changed them to use new official repositories (or [stable-archive repository maintained by GitLab]( https://gitlab.com/gitlab-org/cluster-integration/helm-stable-archive))
+to mitigate the impact.
+Here is [an example fix](https://gitlab.com/gitlab-org/cluster-integration/auto-deploy-image/-/merge_requests/127) in Auto Deploy.
+
+In Auto Deploy, `v1.0.6+` of `auto-deploy-image` no longer adds the deprecated stable repository to `helm` command.
+If you use a custom chart and it relies on the deprecated stable repository,
+please specify an older `auto-deploy-image` like the following example.
+
+```yaml
+include:
+  - template: Auto-DevOps.gitlab-ci.yml
+
+.auto-deploy:
+  image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-deploy-image:v1.0.5"
+```
+
+Please keep in mind that this approach will also eventually stop working
+when the stable repository has been removed, so that you would want to fix your custom chart
+sooner or later.
+
+You can find more information in [this issue](https://gitlab.com/gitlab-org/gitlab/-/issues/263778).
+
 ## Development guides
 
 [Development guide for Auto DevOps](../../development/auto_devops.md)

lib/gitlab/ci/templates/Jobs/DAST-Default-Branch-Deploy.gitlab-ci.yml

 .dast-auto-deploy:
-  image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-deploy-image:v1.0.5"
+  image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-deploy-image:v1.0.6"
 
 dast_environment_deploy:
   extends: .dast-auto-deploy

lib/gitlab/ci/templates/Jobs/Deploy.gitlab-ci.yml

 .auto-deploy:
-  image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-deploy-image:v1.0.5"
+  image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-deploy-image:v1.0.6"
   dependencies: []
 
 review: