add mysqlv for customed version

Author: alwqx

Makefile

@@ -1,10 +1,11 @@
 root_pass=root
 mysql_user=test
 mysql_pass=test
+mysqlv := 5.7
 
 prod:
 	docker run -d --name mysql --net host -v `pwd`/data:/var/lib/mysql -v `pwd`/etc:/etc/mysql/conf.d \
-		-e MYSQL_ROOT_PASSWORD=$(root_pass) -e MYSQL_USER=$(mysql_user) -e MYSQL_PASSWORD=$(mysql_pass) mysql:5.7
+		-e MYSQL_ROOT_PASSWORD=$(root_pass) -e MYSQL_USER=$(mysql_user) -e MYSQL_PASSWORD=$(mysql_pass) mysql:$(mysqlv)
 clean:
 	docker stop mysql
 	docker rm mysql

README.md

@@ -30,9 +30,12 @@
   [mysqld]
   character-set-server=utf8
   ```
-- run image
+- run image. **Note: default mysql version is `5.7`, add mysqlv to make to change mysql version**
   ```
+  # default mysql version is 5.7
   make prod
+  # use customed version by add mysqlv=5.6.25 to make
+  make prod mysqlv=5.6.25
   ```
 
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