docs(argo-workflows): add an HA section (#2183)

* feat(argo-workflows): add a sample HA config

- a `values-ha.yaml` as an example for how one would set-up HA according to the Argo Workflows docs

Signed-off-by: Anton Gilgur <[email protected]>

* docs(argo-workflows): add an HA section

- plus add a test for HA, which the docs link to as an example
- link back to [upstream docs](https://argoproj.github.io/argo-workflows/high-availability/) as well

- follow the same basic structure as the [Argo CD chart for HA](https://github.com/argoproj/argo-helm/blob/3e35b0c7f7d758d553b17f369cc5940484ef5d89/charts/argo-cd/README.md?plain=1#L17)
  - as asked in review

Signed-off-by: Anton Gilgur <[email protected]>

---------

Signed-off-by: Anton Gilgur <[email protected]>
Signed-off-by: Anton Gilgur <[email protected]>
Co-authored-by: Aikawa <[email protected]>

charts/argo-workflows/Chart.yaml

@@ -3,7 +3,7 @@ appVersion: v3.4.11
 name: argo-workflows
 description: A Helm chart for Argo Workflows
 type: application
-version: 0.33.2
+version: 0.33.3
 icon: https://argoproj.github.io/argo-workflows/assets/logo.png
 home: https://github.com/argoproj/argo-helm
 sources:
@@ -16,5 +16,5 @@ annotations:
     fingerprint: 2B8F22F57260EFA67BE1C5824B11F800CD9D2252
     url: https://argoproj.github.io/argo-helm/pgp_keys.asc
   artifacthub.io/changes: |
-    - kind: changed
-      description: Upgrade Argo Workflows to v3.4.11
+    - kind: fixed
+      description: Add HA docs and example

charts/argo-workflows/README.md

@@ -75,6 +75,11 @@ For full list of changes, please check ArtifactHub [changelog].
 
 ## Usage Notes
 
+### High Availability
+
+This chart installs the non-HA version of Argo Workflows by default. If you want to run in HA mode, you can use [these example values](ci/ha-values.yaml) as a starting point.
+Please see the upstream [Operator Manual's High Availability page](https://argoproj.github.io/argo-workflows/high-availability/) to understand how to scale Argo Workflows in depth.
+
 ### Workflow controller
 
 This chart defaults to setting the `controller.instanceID.enabled` to `false` now, which means the deployed controller will act upon any workflow deployed to the cluster. If you would like to limit the behavior and deploy multiple workflow controllers, please use the `controller.instanceID.enabled` attribute along with one of its configuration options to set the `instanceID` of the workflow controller to be properly scoped for your needs.

charts/argo-workflows/README.md.gotmpl

@@ -75,6 +75,11 @@ For full list of changes, please check ArtifactHub [changelog].
 
 ## Usage Notes
 
+### High Availability
+
+This chart installs the non-HA version of Argo Workflows by default. If you want to run in HA mode, you can use [these example values](ci/ha-values.yaml) as a starting point.
+Please see the upstream [Operator Manual's High Availability page](https://argoproj.github.io/argo-workflows/high-availability/) to understand how to scale Argo Workflows in depth.
+
 ### Workflow controller
 
 This chart defaults to setting the `controller.instanceID.enabled` to `false` now, which means the deployed controller will act upon any workflow deployed to the cluster. If you would like to limit the behavior and deploy multiple workflow controllers, please use the `controller.instanceID.enabled` attribute along with one of its configuration options to set the `instanceID` of the workflow controller to be properly scoped for your needs.

charts/argo-workflows/ci/ha-values.yaml

@@ -0,0 +1,23 @@
+# Sample values for High Availability configuration, following https://argoproj.github.io/argo-workflows/high-availability/
+
+controller:
+  # in v3.0+, a second controller can be ran as a hot-standby: https://argoproj.github.io/argo-workflows/high-availability/#workflow-controller
+  replicas: 2 # should be strictly greater than PDB minAvailable
+  # enable PDB with at least one Pod
+  pdb:
+    # -- Configure [Pod Disruption Budget] for the controller pods
+    enabled: true
+    minAvailable: 1
+
+server:
+  # enable HPA with at least two Pods
+  autoscaling:
+    # -- Enable Horizontal Pod Autoscaler ([HPA]) for the Argo Server
+    enabled: true
+    # -- Minimum number of replicas for the Argo Server [HPA]
+    minReplicas: 2 # should be strictly greater than PDB minAvailable
+  # enable PDB with at least one Pod
+  pdb:
+    # -- Configure [Pod Disruption Budget] for the controller pods
+    enabled: true
+    minAvailable: 1