Support grafana additional volumeMounts field. (#3960)

docs/api-references/docs.md

@@ -6150,6 +6150,19 @@ IngressSpec
 <em>(Optional)</em>
 </td>
 </tr>
+<tr>
+<td>
+<code>additionalVolumeMounts</code></br>
+<em>
+<a href="https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.18/#volumemount-v1-core">
+[]Kubernetes core/v1.VolumeMount
+</a>
+</em>
+</td>
+<td>
+<p>Additional volume mounts of grafana pod.</p>
+</td>
+</tr>
 </tbody>
 </table>
 <h3 id="helperspec">HelperSpec</h3>

examples/basic/tidb-monitor.yaml

@@ -3,6 +3,7 @@ kind: TidbMonitor
 metadata:
   name: basic
 spec:
+  replicas: 1
   clusters:
   - name: basic
   prometheus:

examples/monitor-with-externalConfigMap/grafana/README.md

@@ -0,0 +1,50 @@
+# An example describes how to mount a custom dashboard JSON file for Grafana.
+
+> **Note:**
+>
+> This document is to show how to mount a custom dashboard for Grafana in TidbMonitor. 
+> This would help to customize the user's Grafana dashboards.
+
+## Install
+
+The following commands are assumed to be executed in this directory.
+
+Create custom dashboard JSON with configMap:
+
+```bash
+kubectl apply -f custom-dashboard.yaml -n ${namespace}
+```
+
+Install TidbMonitor:
+
+```bash
+kubectl apply -f tidb-monitor.yaml -n ${namespace}
+```
+
+Wait for Pods ready:
+
+```bash
+watch kubectl -n ${namespace} get pod
+```
+
+Explore the monitoring dashboards:
+
+```bash
+kubectl -n  ${namespace} port-forward svc/basic-grafana  3000:3000
+```
+
+Browse [localhost:3000](http://localhost:3000), and check the custom dashboard.
+
+## Uninstall
+
+Uninstall TidbMonitor:
+
+```bash
+kubectl delete -f tidb-monitor.yaml -n ${namespace}
+```
+
+Delete the external configMap:
+
+```bash
+kubectl delete -f custom-dashboard.yaml -n ${namespace}
+```