如何获取容器的启动命令

• 容器早已创建好，如何得知它的启动参数(数据挂载到哪)

#假设通过如下命令启动了一个容器 docker run  -d  --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 --restart=always mysql:5.5 --character-set-server=utf8  #如何通过容器名得知启动参数 [root@jenkins ~]# docker inspect mysql_cdh [     {         "Id": "fbc3fba81b57bc5b5871746098b5f1f7ef0ed7716a786584a5effbb88ba156e6",         "Created": "2019-09-25T01:43:37.720505875Z",         "Path": "docker-entrypoint.sh",         "Args": [             "--character-set-server=utf8"         ],   "HostConfig": {             "Binds": [                 "mysql-data:/var/lib/mysql"             ],             "ContainerIDFile": "",             "LogConfig": {                 "Type": "json-file",                 "Config": {}             },             "NetworkMode": "default",             "PortBindings": {                 "3306/tcp": [                     {                         "HostIp": "",                         "HostPort": "3306"                     }                 ]             },             "RestartPolicy": {                 "Name": "always",                 "MaximumRetryCount": 0             },     "Mounts": [             {                 "Type": "volume",                 "Name": "mysql-data",                 "Source": "/var/lib/docker/volumes/mysql-data/_data",                 "Destination": "/var/lib/mysql",                 "Driver": "local",                 "Mode": "z",                 "RW": true,                 "Propagation": ""             }         ], 

1, 镜像层：文件存放路径

[root@master ~]# docker image inspect nginx |tail  -n 22         "GraphDriver": {             "Data": {                 "LowerDir": "/var/lib/docker/overlay2/bf20cf788cc053f00ff1467525d50e19bd1cf07a2167f72511bdfcb28918a472/diff:/var/lib/docker/overlay2/317d80bb7ae58ed288be9ebd84aeb5b4b3a1c06f3211f5d1f32d89b629d1876e/diff",                 "MergedDir": "/var/lib/docker/overlay2/7782d0eb292fdc8bbd73bf9bae2d65468e8aba0bcd6baed55ac348618b80ae16/merged",                 "UpperDir": "/var/lib/docker/overlay2/7782d0eb292fdc8bbd73bf9bae2d65468e8aba0bcd6baed55ac348618b80ae16/diff",                 "WorkDir": "/var/lib/docker/overlay2/7782d0eb292fdc8bbd73bf9bae2d65468e8aba0bcd6baed55ac348618b80ae16/work"             },             "Name": "overlay2"         }, 

2, 容器层：文件存放路径

#1, 启动容器 [root@master ~]# docker run -d --name nginx2 nginx a9c9f31cdccf13c3385f3de33443325d2e14d69458e6d679e54c8cf9e5ff24c8  #2, 获取容器id [root@master ~]# docker inspect nginx2  | grep -i id  [root@master ~]# docker inspect nginx2  | grep -i id          "Id": "a9c9f31cdccf13c3385f3de33443325d2e14d69458e6d679e54c8cf9e5ff24c8",             "Pid": 2069,         "ExecIDs": null,             "ContainerIDFile": "",     #查看容器临时文件--每次创建时随机生成的文件(容器层) [root@master ~]# docker inspect nginx2  | grep -i path         "Path": "nginx",         "ResolvConfPath": "/var/lib/docker/containers/a9c9f31cdccf13c3385f3de33443325d2e14d69458e6d679e54c8cf9e5ff24c8/resolv.conf",         "HostnamePath": "/var/lib/docker/containers/a9c9f31cdccf13c3385f3de33443325d2e14d69458e6d679e54c8cf9e5ff24c8/hostname",         "HostsPath": "/var/lib/docker/containers/a9c9f31cdccf13c3385f3de33443325d2e14d69458e6d679e54c8cf9e5ff24c8/hosts",         "LogPath": "/var/lib/docker/containers/a9c9f31cdccf13c3385f3de33443325d2e14d69458e6d679e54c8cf9e5ff24c8/a9c9f31cdccf13c3385f3de33443325d2e14d69458e6d679e54c8cf9e5ff24c8-json.log",   #通过容器id, 查找容器数据存放目录： /var/lib/docker/overlay2/容器id ###### #对比上面的“镜像层：文件存放路径”，可以看到 :容器通过LowerDir 挂载的方式，映射了镜像层的文件 ###### [root@master ~]# docker inspect nginx2  | grep -i dir                 "LowerDir": "/var/lib/docker/overlay2/d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b-init/diff:/var/lib/docker/overlay2/7782d0eb292fdc8bbd73bf9bae2d65468e8aba0bcd6baed55ac348618b80ae16/diff:/var/lib/docker/overlay2/bf20cf788cc053f00ff1467525d50e19bd1cf07a2167f72511bdfcb28918a472/diff:/var/lib/docker/overlay2/317d80bb7ae58ed288be9ebd84aeb5b4b3a1c06f3211f5d1f32d89b629d1876e/diff",                 "MergedDir": "/var/lib/docker/overlay2/d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b/merged",                 "UpperDir": "/var/lib/docker/overlay2/d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b/diff",                 "WorkDir": "/var/lib/docker/overlay2/d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b/work" 

后天修改容器端口

通过容器层文件，找到配置文件hostconfig.json，修改容器映射的端口

 [root@docker d93185e3a0....2e544ccfa]# pwd /var/lib/docker/containers/d93185e3a0....2e544ccfa [root@docker d93185e3a0....2e544ccfa]# cat hostconfig.json  {"Binds":["/dockersuperset:/home/superset"],"ContainerIDFile":"", "LogConfig":{"Type":"json-file","Config":{}},"NetworkMode":"default", "PortBindings":{"8088/tcp":[{"HostIp":"","HostPort":"8099"}]}...... 

3, 进入镜容器文件存储目录， 修改配置文件

# 进入镜容器文件存储目录， 修改配置文件 [root@master ~]# cd /var/lib/docker/overlay2/d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# ls diff  link  lower  merged  work  [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# ls diff/run/ nginx.pid [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# ls diff/var/cache/nginx/ client_temp  fastcgi_temp  proxy_temp  scgi_temp  uwsgi_temp  [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# ls merged/ bin/        dev/        etc/        lib/        media/      opt/        root/       sbin/       sys/        usr/         boot/       .dockerenv  home/       lib64/      mnt/        proc/       run/        srv/        tmp/        var/          [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# ls merged/etc/nginx/ conf.d  fastcgi_params  koi-utf  koi-win  mime.types  modules  nginx.conf  scgi_params  uwsgi_params  win-utf  [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# head merged/etc/nginx/nginx.conf  user  nginx; worker_processes  1;  #在此处修改配置文件，把user nginx; worker_process 1; 这两行的分号去掉，看容器里面的配置是否更改 [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# head merged/etc/nginx/nginx.conf -n 3 user  nginx worker_processes  1  #登陆容器，查看修改的配置： 验证是否生效 [root@master d37ff828e63081be6fcfefc73891e7b455596cb921c8021fbf9571f330c0599b]# docker exec -it nginx2 bash root@a9c9f31cdccf:/# head /etc/nginx/nginx.conf -n 3 user  nginx worker_processes  1 

4, 修改默认存储路径

a, 重建/var/lib/docker目录

#备份数据到新的存放路径 service docker stop mkdir /docker.bak mv /var/lib/docker/*  /docker.bak  #创建软连接 mkdir /home/docker-data mv /docker.bak/*  /home/docker-data/ && rmdir /docker.bak ln -s   /home/docker-data  /var/lib/docker 

b, 修改配置

vi /usr/lib/systemd/system/docker.service   ExecStart=/usr/bin/dockerd --graph /new-path/docker   #reload配置文件  systemctl daemon-reload  #重启docker  systemctl restart docker.service