[stable/wordpress] Fix chart not being upgradable (#7831)

* [stable/wordpress] Fix chart not being upgradable

Signed-off-by: Javier J. Salmeron Garcia <jsalmeron@bitnami.com>

* improve markdown highlighting

Signed-off-by: Sameer Naik <sameer@bitnami.com>

stable/wordpress/Chart.yaml

@@ -1,5 +1,5 @@
 name: wordpress
-version: 2.1.10
+version: 3.0.0
 appVersion: 4.9.8
 description: Web publishing platform for building blogs and websites.
 icon: https://bitnami.com/assets/stacks/wordpress/img/wordpress-stack-220x234.png

stable/wordpress/README.md

@@ -230,3 +230,15 @@ kubectl create secret tls wordpress.local-tls --key /path/to/key.key --cert /pat
 
 Please see [this example](https://github.com/kubernetes/contrib/tree/master/ingress/controllers/nginx/examples/tls)
 for more information.
+
+## Upgrading
+
+### To 3.0.0
+
+Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments.
+Use the workaround below to upgrade from versions previous to `3.0.0`. The following example assumes that the release name is `wordpress`:
+
+```console
+$ kubectl patch deployment wordpress-wordpress --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'
+$ kubectl delete statefulset wordpress-mariadb --cascade=false
+```

stable/wordpress/templates/deployment.yaml

@@ -8,6 +8,10 @@ metadata:
     release: "{{ .Release.Name }}"
     heritage: "{{ .Release.Service }}"
 spec:
+  selector:
+    matchLabels:
+      app: {{ template "fullname" . }}
+      release: "{{ .Release.Name }}"
   replicas: {{ .Values.replicaCount }}
   template:
     metadata: