chore(argo-cd): Add chart tests and usage info in README for HA (#951)

* chore: Reconfigure KinD to 1 control-plane and 3 worker nodes

This prepares chart testing of 'argo-cd' chart with redis-ha enabled. Redis-ha defines hard pod anti-affinity and requires multiple worker nodes.

Signed-off-by: Marco Kilchhofer <mkilchhofer@users.noreply.github.com>

* chore(argo-cd): Add chart tests for HA

Signed-off-by: Marco Kilchhofer <mkilchhofer@users.noreply.github.com>

* Add HA chapter to README

Signed-off-by: Marco Kilchhofer <mkilchhofer@users.noreply.github.com>

* Skip HPA tests of ArgoCD

Signed-off-by: Marco Kilchhofer <mkilchhofer@users.noreply.github.com>

charts/argo-cd/ci/default-values.yaml

@@ -0,0 +1 @@
+# Test with default values

charts/argo-cd/ci/ha-autoscaling-values.yaml

@@ -0,0 +1,16 @@
+# Test High Availability with autoscaling
+redis-ha:
+  enabled: true
+
+controller:
+  enableStatefulSet: true
+
+server:
+  autoscaling:
+    enabled: true
+    minReplicas: 2
+
+repoServer:
+  autoscaling:
+    enabled: true
+    minReplicas: 2

charts/argo-cd/ci/ha-static-values.yaml

@@ -0,0 +1,15 @@
+# Test High Availability without autoscaling
+redis-ha:
+  enabled: true
+
+controller:
+  enableStatefulSet: true
+
+server:
+  replicas: 2
+  env:
+    - name: ARGOCD_API_SERVER_REPLICAS
+      value: '2'
+
+repoServer:
+  replicas: 2