docs: Helm plugins via initContainers (argoproj#7815)

* Docs: Helm plugins via initContainers Related: argoproj#7066 Include an alternative method for installing Helm plugins that don't require users to maintain their own version of the ArgoCD container image. Signed-off-by: Didrik Finnøy <[email protected]> * add codeblock Signed-off-by: Didrik Finnøy <[email protected]> * change helm repo name in example code Signed-off-by: Didrik Finnøy <[email protected]>
tkasuz · Dec 19, 2021 · e32c070 · e32c070
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commit e32c070
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diff --git a/docs/user-guide/helm.md b/docs/user-guide/helm.md
@@ -169,9 +169,11 @@ Or via declarative syntax:
 
 Argo CD is un-opinionated on what cloud provider you use and what kind of Helm plugins you are using, that's why there are no plugins delivered with the ArgoCD image.
 
-But sometimes it happens you would like to use a custom plugin. One of the cases is that you would like to use Google Cloud Storage or Amazon S3 storage to save the Helm charts, for example: https://github.com/hayorov/helm-gcs where you can use `gs://` protocol for Helm chart repository access.
+But sometimes you want to use a custom plugin. Perhaps you would like to use Google Cloud Storage or Amazon S3 storage to save the Helm charts, for example: https://github.com/hayorov/helm-gcs where you can use `gs://` protocol for Helm chart repository access.
+There are two ways to install custom plugins; you can modify the ArgoCD container image, or you can use a Kubernetes `initContainer`.
 
-In order to do that you have to prepare your own ArgoCD image with installed plugins.
+### Modifying the ArgoCD container image
+One way to use this plugin is to prepare your own ArgoCD image where it is included.
 
 Example `Dockerfile`:
 
@@ -199,6 +201,62 @@ You have to remember about `HELM_PLUGINS` environment property - this is require
 
 After that you have to use your custom image for ArgoCD installation.
 
+### Using `initContainers`
+Another option is to install Helm plugins via Kubernetes `initContainers`.
+Some users find this pattern preferable to maintaining their own version of the ArgoCD container image.
+
+Below is an example of how to add Helm plugins when installing ArgoCD with the [official ArgoCD helm chart](https://github.com/argoproj/argo-helm/tree/master/charts/argo-cd):
+
+```
+# helm-gcs plugin
+repoServer:
+  volumes:
+    - name: helm
+      emptyDir: {}
+    - name: gcloud
+      secret:
+        secretName: helm-credentials
+  volumeMounts:
+    - mountPath: /helm
+      name: helm
+    - mountPath: /gcloud
+      name: gcloud
+  env:
+    - name: HELM_DATA_HOME
+      value: /helm
+    - name: HELM_CACHE_HOME
+      value: /helm/cache
+    - name: HELM_CONFIG_HOME
+      value: /helm/config
+    - name: HELM_PLUGINS
+      value: /helm/plugins/
+    - name: GOOGLE_APPLICATION_CREDENTIALS
+      value: /gcloud/key.json
+  initContainers:
+    - name: install-helm-plugins
+      image: alpine/helm:3.6.3
+      volumeMounts:
+        - mountPath: /helm
+          name: helm
+        - mountPath: /gcloud
+          name: gcloud
+      env:
+        - name: HELM_DATA_HOME
+          value: /helm
+        - name: HELM_CACHE_HOME
+          value: /helm/cache
+        - name: HELM_CONFIG_HOME
+          value: /helm/config
+        - name: GOOGLE_APPLICATION_CREDENTIALS
+          value: /gcloud/key.json
+      command: ["/bin/sh", "-c"]
+      args:
+        - apk --no-cache add curl;
+          helm plugin install https://github.com/hayorov/helm-gcs.git;
+          helm repo add my-gcs-repo gs://my-private-helm-gcs-repository;
+          chmod -R 777 $HELM_DATA_HOME;
+```
+
 ## Helm Version
 
 Argo CD will assume that the Helm chart is v3 (even if the apiVersion field in the chart is Helm v2), unless v2 is explicitly specified within the Argo CD Application (see below).