Merge branch 'doc-helm-upgrade-extra-args' into 'master'

Documentation for the Helm Upgrade extra args

See merge request gitlab-org/gitlab!41859

doc/topics/autodevops/customize.md

@@ -154,6 +154,16 @@ NOTE: **Note:**
 For GitLab 12.5 and earlier, use the `HELM_UPGRADE_EXTRA_ARGS` environment variable
 to override the default chart values by setting `HELM_UPGRADE_EXTRA_ARGS` to `--values <my-values.yaml>`.
 
+## Customize the `helm upgrade` command
+
+You can customize the `helm upgrade` command used in the [auto-deploy-image](https://gitlab.com/gitlab-org/cluster-integration/auto-deploy-image)
+by passing options to the command with the `HELM_UPGRADE_EXTRA_ARGS` variable.
+For example, set the value of `HELM_UPGRADE_EXTRA_ARGS` to `--no-hooks` to disable
+pre and post upgrade hooks when the command is executed.
+
+See [the official documentation](https://helm.sh/docs/helm/helm_upgrade/) for the full
+list of options.
+
 ## Custom Helm chart per environment
 
 You can specify the use of a custom Helm chart per environment by scoping the environment variable
@@ -331,7 +341,7 @@ applications.
 | `DOCKERFILE_PATH`                       | From GitLab 13.2, allows overriding the [default Dockerfile path for the build stage](#custom-dockerfile) |
 | `HELM_RELEASE_NAME`                     | From GitLab 12.1, allows the `helm` release name to be overridden. Can be used to assign unique release names when deploying multiple projects to a single namespace. |
 | `HELM_UPGRADE_VALUES_FILE`              | From GitLab 12.6, allows the `helm upgrade` values file to be overridden. Defaults to `.gitlab/auto-deploy-values.yaml`. |
-| `HELM_UPGRADE_EXTRA_ARGS`               | From GitLab 11.11, allows extra arguments in `helm` commands when deploying the application. Note that using quotes won't prevent word splitting. |
+| `HELM_UPGRADE_EXTRA_ARGS`               | From GitLab 11.11, allows extra options in `helm upgrade` commands when deploying the application. Note that using quotes won't prevent word splitting. |
 | `INCREMENTAL_ROLLOUT_MODE`              | From GitLab 11.4, if present, can be used to enable an [incremental rollout](#incremental-rollout-to-production) of your application for the production environment. Set to `manual` for manual deployment jobs or `timed` for automatic rollout deployments with a 5 minute delay each one. |
 | `K8S_SECRET_*`                          | From GitLab 11.7, any variable prefixed with [`K8S_SECRET_`](#application-secret-variables) will be made available by Auto DevOps as environment variables to the deployed application. |
 | `KUBE_INGRESS_BASE_DOMAIN`              | From GitLab 11.8, can be used to set a domain per cluster. See [cluster domains](../../user/project/clusters/index.md#base-domain) for more information. |