Merge pull request #383 from acekingke/DebugMode

mysqlcluster: Debug Mode for Pod #375

Author: andyli029

docs/en-us/DebugMode.md

@@ -0,0 +1,15 @@
+# Debug Mode
+When you want avoid the restart-on-fail loop for mysql container, You should use Debug Mode.
+it just use create a empty file  `/var/lib/mysql/sleep-forever`
+for example:
+```bash
+kubectl exec -it sample-mysql-0 -c mysql -- sh -c 'touch /var/lib/mysql/sleep-forever'
+```
+it make pod sample-mysql-0's mysql container will never restart when mysqld is crashed.
+
+# Remove Debug Mode
+
+```bash
+kubectl exec -it sample-mysql-0 -c mysql -- sh -c 'rm /var/lib/mysql/sleep-forever'
+```
+restart the container

mysqlcluster/container/mysql.go

@@ -46,7 +46,11 @@ func (c *mysql) getImage() string {
 
 // getCommand get the container command.
 func (c *mysql) getCommand() []string {
-	return nil
+	return []string{
+		"sh",
+		"-c",
+		"while  [ -f '/var/lib/mysql/sleep-forever' ] ;do sleep 2 ; done; /docker-entrypoint.sh mysqld",
+	}
 }
 
 // getEnvVars get the container env.
@@ -88,7 +92,15 @@ func (c *mysql) getLivenessProbe() *corev1.Probe {
 	return &corev1.Probe{
 		Handler: corev1.Handler{
 			Exec: &corev1.ExecAction{
-				Command: []string{"pgrep", "mysqld"},
+
+				/* /var/lib/mysql/sleep-forever is used to prevent mysql's container from exiting.
+				kubectl exec -it sample-mysql-0 -c mysql -- sh -c 'touch /var/lib/mysql/sleep-forever'
+				*/
+				Command: []string{
+					"sh",
+					"-c",
+					"if [ -f '/var/lib/mysql/sleep-forever' ] ;then exit 0 ; fi; pgrep mysqld",
+				},
 			},
 		},
 		InitialDelaySeconds: 30,
@@ -107,7 +119,7 @@ func (c *mysql) getReadinessProbe() *corev1.Probe {
 				Command: []string{
 					"sh",
 					"-c",
-					fmt.Sprintf(`test $(mysql --defaults-file=%s -NB -e "SELECT 1") -eq 1`, utils.ConfClientPath),
+					fmt.Sprintf(`if [ -f '/var/lib/mysql/sleep-forever' ] ;then exit 0 ; fi; test $(mysql --defaults-file=%s -NB -e "SELECT 1") -eq 1`, utils.ConfClientPath),
 				},
 			},
 		},

mysqlcluster/container/mysql_test.go

@@ -58,7 +58,8 @@ func TestGetMysqlImage(t *testing.T) {
 }
 
 func TestGetMysqlCommand(t *testing.T) {
-	assert.Nil(t, mysqlCase.Command)
+	assert.Equal(t, mysqlCase.Command,
+		[]string{"sh", "-c", "while  [ -f '/var/lib/mysql/sleep-forever' ] ;do sleep 2 ; done; /docker-entrypoint.sh mysqld"})
 }
 
 func TestGetMysqlEnvVar(t *testing.T) {
@@ -109,7 +110,7 @@ func TestGetMysqlLivenessProbe(t *testing.T) {
 	livenessProbe := &corev1.Probe{
 		Handler: corev1.Handler{
 			Exec: &corev1.ExecAction{
-				Command: []string{"pgrep", "mysqld"},
+				Command: []string{"sh", "-c", "if [ -f '/var/lib/mysql/sleep-forever' ] ;then exit 0 ; fi; pgrep mysqld"},
 			},
 		},
 		InitialDelaySeconds: 30,
@@ -125,7 +126,7 @@ func TestGetMysqlReadinessProbe(t *testing.T) {
 	readinessProbe := &corev1.Probe{
 		Handler: corev1.Handler{
 			Exec: &corev1.ExecAction{
-				Command: []string{"sh", "-c", `test $(mysql --defaults-file=/etc/mysql/client.conf -NB -e "SELECT 1") -eq 1`},
+				Command: []string{"sh", "-c", `if [ -f '/var/lib/mysql/sleep-forever' ] ;then exit 0 ; fi; test $(mysql --defaults-file=/etc/mysql/client.conf -NB -e "SELECT 1") -eq 1`},
 			},
 		},
 		InitialDelaySeconds: 10,