Merge branch 'master' into cdc-graceful-upgrade

docs/api-references/docs.md

@@ -4669,7 +4669,13 @@ Note that the following env names cannot be used and will be overridden by TiDB
 </td>
 <td>
 <em>(Optional)</em>
-<p>Additional containers of the component.</p>
+<p>Additional containers of the component.
+If the container names in this field match with the ones generated by
+TiDB Operator, the container configurations will be merged into the
+containers generated by TiDB Operator via strategic merge patch.
+If the container names in this field do not match with the ones
+generated by TiDB Operator, the container configurations will be
+appended to the Pod container spec directly.</p>
 </td>
 </tr>
 <tr>

examples/podpatch/README.md

@@ -0,0 +1,48 @@
+# Container merge patch strategic
+
+> When users need to apply a specific configuration to containers that we do not support or do not currently exist, merge patch can be used.
+> This document describes how to overwrite the container configuration generated by the operator by merging patches.
+
+## How the "strategic merge patch" works
+
+The operator supports `additionalContainers` field in `TidbCluster.spec.pd`, `TidbCluster.spec.tikv`, `TidbCluster.spec.tidb`,`TidbMonitor.spec` configuration etc. 
+This field allows injecting additional containers, and the existing configuration can be overwritten by sharing the same container name.
+
+### Merge patch example of pd pod
+
+The following manifest merge the `lifecycle` configuration into pd container.
+
+```yaml
+apiVersion: pingcap.com/v1alpha1
+kind: TidbCluster
+metadata:
+  name: basic
+spec:
+  version: v5.4.1
+  timezone: UTC
+  pvReclaimPolicy: Retain
+  enableDynamicConfiguration: true
+  configUpdateStrategy: RollingUpdate
+  discovery: {}
+  helper:
+    image: busybox:1.34.1
+  pd:
+    baseImage: pingcap/pd
+    maxFailoverCount: 0
+    replicas: 1
+    # if storageClassName is not set, the default Storage Class of the Kubernetes cluster will be used
+    # storageClassName: local-storage
+    requests:
+      storage: "1Gi"
+    config: {}
+    additionalContainers:
+      - name: pd
+        lifecycle:
+          preStop:
+            exec:
+              command:
+                - "sh"
+                - "-c"
+                - |
+                  echo "test"
+```

examples/podpatch/tidb-cluster.yaml

@@ -0,0 +1,64 @@
+# IT IS NOT SUITABLE FOR PRODUCTION USE.
+# This YAML describes a basic TiDB cluster with minimum resource requirements,
+# which should be able to run in any Kubernetes cluster with storage support.
+apiVersion: pingcap.com/v1alpha1
+kind: TidbCluster
+metadata:
+  name: basic
+spec:
+  version: v5.4.1
+  timezone: UTC
+  pvReclaimPolicy: Retain
+  enableDynamicConfiguration: true
+  configUpdateStrategy: RollingUpdate
+  discovery: {}
+  helper:
+    image: busybox:1.34.1
+  pd:
+    baseImage: pingcap/pd
+    maxFailoverCount: 0
+    replicas: 1
+    # if storageClassName is not set, the default Storage Class of the Kubernetes cluster will be used
+    # storageClassName: local-storage
+    requests:
+      storage: "1Gi"
+    config: {}
+    additionalContainers:
+      - name: pd
+        lifecycle:
+          preStop:
+            exec:
+              command:
+                - "sh"
+                - "-c"
+                - |
+                  echo "test"
+  tikv:
+    baseImage: pingcap/tikv
+    maxFailoverCount: 0
+    # If only 1 TiKV is deployed, the TiKV region leader 
+    # cannot be transferred during upgrade, so we have
+    # to configure a short timeout
+    evictLeaderTimeout: 1m
+    replicas: 1
+    # if storageClassName is not set, the default Storage Class of the Kubernetes cluster will be used
+    # storageClassName: local-storage
+    requests:
+      storage: "1Gi"
+    config:
+      storage:
+        # In basic examples, we set this to avoid using too much storage.
+        reserve-space: "0MB"
+      rocksdb:
+        # In basic examples, we set this to avoid the following error in some Kubernetes clusters:
+        # "the maximum number of open file descriptors is too small, got 1024, expect greater or equal to 82920"
+        max-open-files: 256
+      raftdb:
+        max-open-files: 256
+  tidb:
+    baseImage: pingcap/tidb
+    maxFailoverCount: 0
+    replicas: 1
+    service:
+      type: ClusterIP
+    config: {}

examples/podpatch/tidb-monitor.yaml

@@ -0,0 +1,35 @@
+apiVersion: pingcap.com/v1alpha1
+kind: TidbMonitor
+metadata:
+  name: basic
+spec:
+  replicas: 1
+  clusters:
+  - name: basic
+  prometheus:
+    baseImage: prom/prometheus
+    version: v2.27.1
+  grafana:
+    baseImage: grafana/grafana
+    version: 7.5.11
+  initializer:
+    baseImage: pingcap/tidb-monitor-initializer
+    version: v5.4.1
+  reloader:
+    baseImage: pingcap/tidb-monitor-reloader
+    version: v1.0.1
+  prometheusReloader:
+    baseImage: quay.io/prometheus-operator/prometheus-config-reloader
+    version: v0.49.0
+  imagePullPolicy: IfNotPresent
+  additionalContainers:
+    - name: test
+      image: busybox:1.34.1
+      lifecycle:
+        preStop:
+          exec:
+            command:
+              - "sh"
+              - "-c"
+              - |
+                echo "test"