docker中的Mysql数据卷与持久化

本文通过两个mysql容器(一个挂载一个无挂载)测试docker的持久化

结论

容器状态/持久化	无挂载	有挂载
pause	Y	Y
stop->start	Y	Y
rm -> up	N	Y

环境

mac docker-compose

 ~/Workspace/docker/volume-learn � docker-compose -v
 
docker-compose version 1.23.2, build 1110ad01

 ~/Workspace/docker/volume-learn � docker version
Client: Docker Engine - Community
 Version:           18.09.2
 API version:       1.39
 Go version:        go1.10.8
 Git commit:        6247962
 Built:             Sun Feb 10 04:12:39 2019
 OS/Arch:           darwin/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.2
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.6
  Git commit:       6247962
  Built:            Sun Feb 10 04:13:06 2019
  OS/Arch:          linux/amd64
  Experimental:     false

步骤

docker-compose.yml

version: '3'

services:

    mysql_1:
        image: mysql:5.7
        container_name: test_mysql_1
        environment:
            - MYSQL_ROOT_PASSWORD=123456
            - MYSQL_DATABASE=base
            - MYSQL_USER=dbuser
            - MYSQL_PASSWORD=topsecret
            - MYSQL_PORT=3306
        ports:
            - "3306:3306"
    mysql_2:
        image: mysql:5.7
        container_name: test_mysql_2
        environment:
            - MYSQL_ROOT_PASSWORD=123456
            - MYSQL_DATABASE=base
            - MYSQL_USER=dbuser
            - MYSQL_PASSWORD=topsecret
            - MYSQL_PORT=3306
        ports:
            - "3307:3306"
        volumes:
            - ./data/mysql_db:/var/lib/mysql

启动

docker-compose up -d
Creating test_mysql_1 ... done
Creating test_mysql_2 ... done

查看挂载情况

docker volume ls
DRIVER              VOLUME NAME
local               8c45070e36f1884b5d8a38fe73667fd0ed2bd6bfb8ad55ca6ff66f1fcebded6d

 ~/Workspace/docker/volume-learn > � docker inspect test_mysql_1 | grep Mounts -A 10
        "Mounts": [
            {
                "Type": "volume",
                "Name": "8c45070e36f1884b5d8a38fe73667fd0ed2bd6bfb8ad55ca6ff66f1fcebded6d",
                "Source": "/var/lib/docker/volumes/8c45070e36f1884b5d8a38fe73667fd0ed2bd6bfb8ad55ca6ff66f1fcebded6d/_data",
                "Destination": "/var/lib/mysql",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
 ~/Workspace/docker/volume-learn >� docker inspect test_mysql_2 | grep Mounts -A 10
        "Mounts": [
            {
                "Type": "bind",
                "Source": "/Users/lifan/Workspace/docker/volume-learn/data/mysql_db",
                "Destination": "/var/lib/mysql",
                "Mode": "rw",
                "RW": true,
                "Propagation": "rprivate"
            }
        ],
        "Config": {

 ~/Workspace/docker/volume-learn � ll
total 8
drwxr-xr-x  3 lifan  staff   102B  8  5 16:46 data
-rw-r--r--  1 lifan  staff   713B  8  5 16:50 docker-compose.yml

MacOS 进入默认挂载目录

mac OS

cd ~/Library/Containers/com.docker.docker/Data/vms/0/
screen tty
# 页面悬停
Ctrl + C

linuxkit-025000000001:~# cd /var/lib/docker/volumes/
linuxkit-025000000001:/var/lib/docker/volumes# ls
8c45070e36f1884b5d8a38fe73667fd0ed2bd6bfb8ad55ca6ff66f1fcebded6d
metadata.db
linuxkit-025000000001:/var/lib/docker/volumes#

# 同时按住Ctrl和a，然后放开再按下d
Ctrl + A  D # 退出
screen -r # 重新登入

# 同时按住Ctrl和a，然后放开再按下k
Ctrl + A + K # 彻底退出

写入数据

test_mysql_1

CREATE TABLE `user_1` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

test_mysql_2

CREATE TABLE `user_2` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

测试

停止重启

 ~/Workspace/docker/volume-learn � docker-compose stop
Stopping test_mysql_2 ... done
Stopping test_mysql_1 ... done
 ~/Workspace/docker/volume-learn � docker-compose start
Starting mysql_1 ... done
Starting mysql_2 ... done

两个数据都还在

暂停重启

 ~/Workspace/docker/volume-learn � docker-compose pause
Pausing test_mysql_1 ... done
Pausing test_mysql_2 ... done

 ~/Workspace/docker/volume-learn � docker inspect test_mysql_1
[
    {
        "Id": "55193429b7f8b548bcc74ac02239468ef80b439a81597a68503e6ed37097fa78",
        "Created": "2019-08-05T09:00:36.5867032Z",
        "Path": "docker-entrypoint.sh",
        "Args": [
            "mysqld"
        ],
        "State": {
            "Status": "paused",
            "Running": true,
            "Paused": true,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 37015,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2019-08-05T09:49:14.9745542Z",
            "FinishedAt": "2019-08-05T09:44:37.1531094Z"
        },

 ~/Workspace/docker/volume-learn � docker-compose unpause
Unpausing test_mysql_2 ... done
Unpausing test_mysql_1 ... done

数据没有丢失

删除容器重启

 ~/Workspace/docker/volume-learn � docker-compose stop
Stopping test_mysql_2 ... done
Stopping test_mysql_1 ... done
 ~/Workspace/docker/volume-learn � docker container ls -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
317f7f035b4e        mysql:5.7           "docker-entrypoint.s…"   About an hour ago   Exited (0) 27 seconds ago                       test_mysql_2
55193429b7f8        mysql:5.7           "docker-entrypoint.s…"   About an hour ago   Exited (0) 27 seconds ago                       test_mysql_1
1e330d4da45d        46f8a1ba43b9        "./web"                  About an hour ago   Up About an hour                                k8s_leeroy-web_leeroy-web-66575d8bc7-t4n88_default_f3fe20ff-8b43-11e9-8f64-025000000001_1
1aabdb1a4df2        4e70f93f0150        "./app"                  About an hour ago   Up About an hour                                k8s_leeroy-app_leeroy-app-5b597594f4-7kwwr_default_f3dc703c-8b43-11e9-8f64-025000000001_1
 ~/Workspace/docker/volume-learn �

 ~/Workspace/docker/volume-learn � docker container prune -f
Deleted Containers:
317f7f035b4e6bd80f987119acb9280735572dfa4fb74492aa365acf89b66e7b
55193429b7f8b548bcc74ac02239468ef80b439a81597a68503e6ed37097fa78
df6251c751c704805fa682a2950b50102589790099f4abd29a3d0c8d37f38ec4
3f513d14c78300cbc88fdc794326caaca5caea549110ceeb8288b5223f314dd4
a9f27228b8e6754594152f9566e7864ec0780c57ef7bf215a2bcf0423bee5d24
a8992b319d0af91a8d69f8c37e7f76068e84cbdb3a1816dffeaa9f1ce1b09dbf

Total reclaimed space: 0B

docker-compose up 

test_mysql_2 数据没有丢失
test_mysql_1 数据丢失

 ~/Workspace/docker/volume-learn � docker inspect test_mysql_1 | grep Mounts -A 10
        "Mounts": [
            {
                "Type": "volume",
                "Name": "695c64bb2b3e0d36e4c14170aca4ba2e81dba29915458e8384456eb7751351d0",
                "Source": "/var/lib/docker/volumes/695c64bb2b3e0d36e4c14170aca4ba2e81dba29915458e8384456eb7751351d0/_data",
                "Destination": "/var/lib/mysql",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
 ~/Workspace/docker/volume-learn � docker volume ls
DRIVER              VOLUME NAME
local               8c45070e36f1884b5d8a38fe73667fd0ed2bd6bfb8ad55ca6ff66f1fcebded6d
local               695c64bb2b3e0d36e4c14170aca4ba2e81dba29915458e8384456eb7751351d0

删除test_mysql_2的挂载目录再重启

直接删除挂载目录

容器没有停止

 ~/Workspace/docker/volume-learn � ll
total 8
drwxr-xr-x  3 lifan  staff   102B  8  5 16:46 data
-rw-r--r--  1 lifan  staff   713B  8  5 16:50 docker-compose.yml
 ~/Workspace/docker/volume-learn � rm -rf data
 ~/Workspace/docker/volume-learn �
 

访问数据库，可以连接，但是没有数据

创建数据库失败

create database base;

Can't create database 'base' (errno: 1808635584)

重启容器

data目录被创建，再次挂载到主机目录

 ~/Workspace/docker/volume-learn � docker-compose stop
Stopping test_mysql_2 ... done
Stopping test_mysql_1 ... done
 ~/Workspace/docker/volume-learn � docker-compose start
Starting mysql_1 ... done
Starting mysql_2 ... done
 ~/Workspace/docker/volume-learn � ll
total 8
drwxr-xr-x  3 lifan  staff   102B  8  5 18:25 data
-rw-r--r--  1 lifan  staff   713B  8  5 16:50 docker-compose.yml
 ~/Workspace/docker/volume-learn �

创建表，写入数据

CREATE TABLE `user_2` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

停止删除容器再启动

 ~/Workspace/docker/volume-learn � docker-compose stop
Stopping test_mysql_2 ... done
Stopping test_mysql_1 ... done
 ~/Workspace/docker/volume-learn � docker rm 77466edd2bd2
77466edd2bd2
 ~/Workspace/docker/volume-learn � docker-compose up -d
Starting test_mysql_1 ... done
Creating test_mysql_2 ... done
 ~/Workspace/docker/volume-learn �

数据还在,容器工作正常