docs,hack: support manual repair the Invalid Pod #331

Author: acekingke

docs/rebuild.md

@@ -0,0 +1,14 @@
+# Why need rebuild ?
+RadonDB cluster is semisynchronous replication mysql cluster. Because MySQL Semisynchronous Replication, It has a chance that the slave has more data than master, So when the xenon check it, It will lable the pod INVALID. When it happend, You
+need rebuild the INVALID pod.
+
+# How to use ?
+Before you want to rebuild the pod, you need to manually check the security and consistency of the cluster.
+
+```shell
+./hack/rebuild.sh PODNAME
+```
+**for example**
+```shell
+./hack/rebuild.sh sample-mysql-2
+```

hack/rebuild.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+## This script is used to rebuild the pod.
+## useage : ./rebuild.sh pod_name
+function check_pod_status(){
+    POD_STATUS=$(kubectl get pods $POD_NAME -o jsonpath='{.status.phase}')
+    if [ "$POD_STATUS" == "Running" ]; then
+        echo "Pod $POD_NAME is running."
+    else
+        echo "Pod $POD_NAME is not running."
+        exit 1
+    fi
+}
+function rebuild_pod(){
+    INVALID=$(kubectl exec -it $POD_NAME -c xenon -- xenoncli raft status | grep "INVALID")
+    if [ -z $INVALID ]; then
+        echo "Pod in Raft is not in invalid state, please check your cluster status."
+        exit 1
+    fi
+
+    kubectl exec -it $POD_NAME -c mysql  -- rm  -rf /var/lib/mysql/*
+
+    sleep 5
+    kubectl delete pod $POD_NAME
+    echo "Rebuild mysql success."
+}
+
+if [ "$#" -ne 1 ]; then
+  echo "Usage: $0 POD_NAME." >&2
+  exit 1
+fi
+POD_NAME=$1
+echo "Rebuilding is danagerous job, Before doing this, please make sure your cluster data is safe and consistent."
+while true; do
+    read -p "Do you want to do it (y/n)?" yn
+    case $yn in
+        [Yy]* ) check_pod_status; rebuild_pod;break;;
+        [Nn]* ) exit;;
+        * ) echo "Please answer yes or no.";;
+    esac
+done
+