helm: Add sidebar support with an example.

kubernetes/chart/zulip/templates/statefulset.yaml

@@ -36,6 +36,11 @@ spec:
       securityContext:
         {{- toYaml .Values.podSecurityContext | nindent 8 }}
       containers:
+        {{- if .Values.sidecars }}
+        {{- with .Values.sidecars }}
+        {{- toYaml . | nindent 8 }}
+        {{- end }}
+        {{- end }}
         - name: {{ .Chart.Name }}
           securityContext:
             {{- toYaml .Values.securityContext | nindent 12 }}
@@ -82,6 +87,7 @@ spec:
             successThreshold: {{ .Values.startupProbe.successThreshold }}
             failureThreshold: {{ .Values.startupProbe.failureThreshold }}
           {{- end }}
+
       volumes:
         - name: {{ include "zulip.fullname" . }}-persistent-storage
           persistentVolumeClaim:

kubernetes/chart/zulip/values.yaml

@@ -179,6 +179,17 @@ postSetup:
     #   #!/bin/bash
     #   echo "This is a script that gets executed in the Zulip container after installation, once migrations are complete"
 
+  # -- You can add any sidecar to Zulip, like a minio client to use for
+  # uploading backups to a bucket, and mounting the volume for Zulip.
+  # sidecars:
+  #   - image: minio/mc
+  #     name: minio-client
+  #     volumeMounts:
+  #       - name: zulip-data
+  #         mountPath: /data
+sidecars:
+  []
+
 # -- PostgreSQL settings, see [Requirements](#Requirements).
 postgresql:
   primary: