Add leader election and pod anti affinity to chart

charts/flagger/README.md

@@ -64,6 +64,8 @@ Parameter | Description | Default
 `slack.channel` | Slack channel | None
 `slack.user` | Slack username | `flagger`
 `msteams.url` | Microsoft Teams incoming webhook | None
+`leaderElection.enabled` | leader election must be enabled when running more than one replica | `false`
+`leaderElection.replicaCount` | number of replicas | `1`
 `rbac.create` | if `true`, create and use RBAC resources | `true`
 `rbac.pspEnabled` | If `true`, create and use a restricted pod security policy | `false`
 `crd.create` | if `true`, create Flagger's CRDs | `true`

charts/flagger/templates/deployment.yaml

@@ -8,7 +8,7 @@ metadata:
     app.kubernetes.io/managed-by: {{ .Release.Service }}
     app.kubernetes.io/instance: {{ .Release.Name }}
 spec:
-  replicas: 1
+  replicas: {{ .Values.leaderElection.replicaCount }}
   strategy:
     type: Recreate
   selector:
@@ -22,6 +22,16 @@ spec:
         app.kubernetes.io/instance: {{ .Release.Name }}
     spec:
       serviceAccountName: {{ template "flagger.serviceAccountName" . }}
+      affinity:
+        podAntiAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 100
+              podAffinityTerm:
+                labelSelector:
+                  matchLabels:
+                    app.kubernetes.io/name: {{ template "flagger.name" . }}
+                    app.kubernetes.io/instance: {{ .Release.Name }}
+                topologyKey: kubernetes.io/hostname
       containers:
         - name: flagger
           securityContext:
@@ -54,6 +64,10 @@ spec:
           {{- if .Values.msteams.url }}
           - -msteams-url={{ .Values.msteams.url }}
           {{- end }}
+          {{- if .Values.leaderElection.enabled }}
+          - -enable-leader-election=true
+          - -leader-election-namespace={{ .Release.Namespace }}
+          {{- end }}
           livenessProbe:
             exec:
               command:
@@ -78,10 +92,6 @@ spec:
 {{ toYaml .Values.resources | indent 12 }}
     {{- with .Values.nodeSelector }}
       nodeSelector:
-{{ toYaml . | indent 8 }}
-    {{- end }}
-    {{- with .Values.affinity }}
-      affinity:
 {{ toYaml . | indent 8 }}
     {{- end }}
     {{- with .Values.tolerations }}

charts/flagger/values.yaml

@@ -23,6 +23,10 @@ msteams:
   # MS Teams incoming webhook URL
   url:
 
+leaderElection:
+  enabled: false
+  replicaCount: 1
+
 serviceAccount:
   # serviceAccount.create: Whether to create a service account or not
   create: true
@@ -54,8 +58,6 @@ nodeSelector: {}
 
 tolerations: []
 
-affinity: {}
-
 prometheus:
   # to be used with AppMesh or nginx ingress
   install: false