feat(argo-cd): Replace Application Controller StatefullSet with a Deployment and enabled autoscaling

Signed-off-by: SIRICA1 <ricardo.silva@mercedes-benz.io>

charts/argo-cd/Chart.yaml

@@ -3,7 +3,7 @@ appVersion: v2.6.4
 kubeVersion: ">=1.22.0-0"
 description: A Helm chart for Argo CD, a declarative, GitOps continuous delivery tool for Kubernetes.
 name: argo-cd
-version: 5.25.0
+version: 5.25.1
 home: https://github.com/argoproj/argo-helm
 icon: https://argo-cd.readthedocs.io/en/stable/assets/logo.png
 sources:
@@ -23,5 +23,5 @@ dependencies:
     condition: redis-ha.enabled
 annotations:
   artifacthub.io/changes: |
-    - kind: added
-      description: Add parameter env to redis exporter
+    - kind: changed
+      description: Replace Application Controller StatefullSet with a Deployment and enabled autoscaling

charts/argo-cd/README.md

@@ -29,7 +29,9 @@ redis-ha:
   enabled: true
 
 controller:
-  replicas: 1
+  autoscaling:
+    enabled: true
+    minReplicas: 2
 
 server:
   autoscaling:
@@ -72,7 +74,7 @@ When installing Argo CD using this helm chart the user should have a similar exp
 
 To update the templates and default settings in `values.yaml` it may come in handy to look up the diff of the `manifests/install.yaml` between two versions accordingly. This can either be done directly via github and look for `manifests/install.yaml`:
 
-https://github.com/argoproj/argo-cd/compare/v1.8.7...v2.0.0#files_bucket
+<https://github.com/argoproj/argo-cd/compare/v1.8.7...v2.0.0#files_bucket>
 
 Or you clone the repository and do a local `git-diff`:
 
@@ -171,9 +173,9 @@ done
 
 This version **removes support for**:
 
-- deprecated repository credentials (parameter `configs.repositoryCredentials`)
-- option to run application controller as a Deployment
-- the parameters `server.additionalApplications` and `server.additionalProjects`
+* deprecated repository credentials (parameter `configs.repositoryCredentials`)
+* option to run application controller as a Deployment
+* the parameters `server.additionalApplications` and `server.additionalProjects`
 
 Please carefully read the following section if you are using these parameters!
 
@@ -351,8 +353,8 @@ server:
 
 ## Prerequisites
 
-- Kubernetes: `>=1.22.0-0`
-- Helm v3.0.0+
+* Kubernetes: `>=1.22.0-0`
+* Helm v3.0.0+
 
 ## Installing the Chart
 
@@ -956,7 +958,7 @@ server:
 
 ### Option 2 - Redis HA
 
-This option uses the following third-party chart to bootstrap a clustered Redis: https://github.com/DandyDeveloper/charts/tree/master/charts/redis-ha.
+This option uses the following third-party chart to bootstrap a clustered Redis: <https://github.com/DandyDeveloper/charts/tree/master/charts/redis-ha>.
 For all available configuration options, please read upstream README and/or chart source.
 The main options are listed here:
 

charts/argo-cd/templates/argocd-application-controller/deployment.yaml

@@ -1,7 +1,7 @@
 apiVersion: apps/v1
-kind: StatefulSet
+kind: Deployment
 metadata:
-  {{- with (mergeOverwrite (deepCopy .Values.global.statefulsetAnnotations) .Values.controller.statefulsetAnnotations) }}
+  {{- with (mergeOverwrite (deepCopy .Values.global.deploymentAnnotations) .Values.controller.deploymentAnnotations) }}
   annotations:
     {{- range $key, $value := . }}
     {{ $key }}: {{ $value | quote }}
@@ -11,10 +11,10 @@ metadata:
   labels:
     {{- include "argo-cd.labels" (dict "context" . "component" .Values.controller.name "name" .Values.controller.name) | nindent 4 }}
 spec:
+  {{- if not .Values.controller.autoscaling.enabled }}
   replicas: {{ .Values.controller.replicas }}
-  # TODO: Remove for breaking release as history limit cannot be patched
-  revisionHistoryLimit: 5
-  serviceName: {{ include "argo-cd.controller.fullname" . }}
+  {{- end }}
+  revisionHistoryLimit: {{ .Values.global.revisionHistoryLimit }}
   selector:
     matchLabels:
       {{- include "argo-cd.selectorLabels" (dict "context" . "name" .Values.controller.name) | nindent 6 }}

charts/argo-cd/templates/argocd-application-controller/hpa.yaml

@@ -0,0 +1,44 @@
+{{- if .Values.controller.autoscaling.enabled }}
+apiVersion: {{ include "argo-cd.apiVersion.autoscaling" . }}
+kind: HorizontalPodAutoscaler
+metadata:
+  labels:
+    {{- include "argo-cd.labels" (dict "context" . "component" .Values.controller.name "name" (printf "%s-hpa" .Values.controller.name)) | nindent 4 }}
+  name: {{ template "argo-cd.controller.fullname" . }}-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: {{ template "argo-cd.controller.fullname" . }}
+  minReplicas: {{ .Values.controller.autoscaling.minReplicas }}
+  maxReplicas: {{ .Values.controller.autoscaling.maxReplicas }}
+  metrics:
+  {{- with .Values.controller.autoscaling.targetMemoryUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: memory
+        {{- if eq (include "argo-cd.apiVersion.autoscaling" $) "autoscaling/v2beta1" }}
+        targetAverageUtilization: {{ . }}
+        {{- else }}
+        target:
+          averageUtilization: {{ . }}
+          type: Utilization
+        {{- end }}
+  {{- end }}
+  {{- with .Values.controller.autoscaling.targetCPUUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: cpu
+        {{- if eq (include "argo-cd.apiVersion.autoscaling" $) "autoscaling/v2beta1" }}
+        targetAverageUtilization: {{ . }}
+        {{- else }}
+        target:
+          averageUtilization: {{ . }}
+          type: Utilization
+        {{- end }}
+  {{- end }}
+  {{- with .Values.controller.autoscaling.behavior }}
+  behavior:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+{{- end }}