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_cdh \
-p 3306:3306 \
-e MYSQL_ROOT_PASSWORD=123456 \
-v mysql-data:/var/lib/mysql \
--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": "3aad772538b5e86705d3358362517a08d53f951aa6522e2881321135f05c8872",
        "Created": "2019-09-25T01:43:37.720505875Z",
        "Path": "docker-entrypoint.sh",
        "Args": [
            "--character-set-server=utf8"
        ],
        ...
        "Name": "/mysql_cdh",
     
	  	"HostConfig": {
	            "Binds": [
	                "mysql-data:/var/lib/mysql"
	            ],
	            ...
	            "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": ""
	            }
	        ],
	
		"Config": {
	            "Hostname": "3aad772538b5",
	             ...
	            "ExposedPorts": {
	                "3306/tcp": {}
	            },
				...
	            "Env": [
	                "MYSQL_ROOT_PASSWORD=123456",
	                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/mysql/bin:/usr/local/mysql/scripts",
	                "GOSU_VERSION=1.7",
	                "MYSQL_MAJOR=5.5",
	                "MYSQL_VERSION=5.5.62"
	            ],
	            "Cmd": [
	                "--character-set-server=utf8"
	            ],

1, 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)
# /var/lib/docker/containers/容器id
[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",

后天修改容器端口

a, 先提交旧容器为新的镜像,再启动新容器

  • 需要确保:数据卷映射完全一致(新旧的容器,在数据卷上要一致)
[root1@c7-docker ~]#  docker inspect mysql_port |egrep -i 'volum|Mount' -A 2
            "Volumes": {
                "/var/lib/mysql": {}
            },
--
            "Volumes": {
                "/var/lib/mysql": {}
            },

  • 保存容器为镜像,再启动新容器是,添加端口映射
##############  1, 启动一个容器 ############## 
[root1@c7-docker ~]# docker run --name t1 -d -e MYSQL_ROOT_PASSWORD=123456 -v mysql-test-dir:/var/lib/mysql/ -p 3308:3306 mysql:5.5
53f2a3c53d4c6769897ee484c3d2ff4e3f82ea1e390d4950b2162c08af05d7cc

[root1@c7-docker ~]# docker ps
CONTAINER ID        IMAGE                             COMMAND                  CREATED             STATUS              PORTS                                              NAMES
53f2a3c53d4c        mysql:5.5                         "docker-entrypoint.s…"   3 seconds ago       Up 3 seconds        0.0.0.0:3308->3306/tcp                             t1

[root1@c7-docker ~]# mysql -uroot -p123456 -P3308 --protocol tcp
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.62 MySQL Community Server (GPL)
MySQL [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.00 sec)

MySQL [(none)]> create database test;
Query OK, 1 row affected (0.00 sec)

MySQL [(none)]> use test;
Database changed
MySQL [test]> create table t1(id int);
Query OK, 0 rows affected (0.00 sec)

MySQL [test]> insert into t1 values(1),(2),(3);
Query OK, 3 rows affected (0.00 sec)
Records: 3  Duplicates: 0  Warnings: 0

MySQL [test]> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
+------+
3 rows in set (0.00 sec)



 
############## 2, 提交当前容器环境--保存为新的镜像 ############## 
[root1@c7-docker ~]# docker commit -m mysql_test_chag-port_img  t1 mysql_port
sha256:9f90be3c200c6a8b535478375c4caf86d589d231afae1293d28026f9248f8ae3
[root1@c7-docker ~]# docker images
REPOSITORY                  TAG                 IMAGE ID            CREATED             SIZE
mysql_port                  latest              9f90be3c200c        3 seconds ago       205MB
mysql                       5.5                 d404d78aa797        18 months ago       205MB



############## 3, 停止旧容器, 启动新容器 ############## 
[root1@c7-docker ~]# docker stop t1
t1
[root1@c7-docker ~]# docker run --name t2 -d -v mysql-test-dir:/var/lib/mysql/ -p 3309:3306 mysql_port
fd7cefe55db8bb2687ab044ff1473f0c935ac5ce867df81b3b13f570e9026868
[root1@c7-docker ~]# docker ps
CONTAINER ID        IMAGE                             COMMAND                  CREATED             STATUS              PORTS                                              NAMES
fd7cefe55db8        mysql_port                        "docker-entrypoint.s…"   3 seconds ago       Up 2 seconds        0.0.0.0:3309->3306/tcp                             t2

[root1@c7-docker ~]# mysql -uroot -p123456 -P3309 --protocol tcp
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.5.62 MySQL Community Server (GPL)
MySQL [(none)]> show databases;

MySQL [(none)]> use test;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MySQL [test]> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
+------+
3 rows in set (0.00 sec)

b, 修改容器配置文件置文件:hostconfig.json

  • 要先停止docker服务,否则不生效
  • 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 a9c9f31cd...ff24c8]# pwd
/var/lib/docker/containers/d93185e3a0....2e544ccfa
[root@docker a9c9f31cd...ff24c8]# cat hostconfig.json 
{"Binds":["/dockersuperset:/home/superset"],"ContainerIDFile":"",
"LogConfig":{"Type":"json-file","Config":{}},"NetworkMode":"default",
"PortBindings":{"8088/tcp":[{"HostIp":"","HostPort":"8099"}]}......

2, 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"
        },

a, 容器层,镜像层:关联

I, 子容器:拷贝镜像的文件

在这里插入图片描述

II, 子容器:添加新文件

在这里插入图片描述

III, 子容器:修改由镜像拷贝的文件

在这里插入图片描述

b, 在镜像层(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 d37ff828e6308...0c0599b]# ls diff/run/
nginx.pid
[root@master d37ff828e6308...0c0599b]# ls diff/var/cache/nginx/
client_temp  fastcgi_temp  proxy_temp  scgi_temp  uwsgi_temp

[root@master d37ff828e6308...0c0599b]# ls merged/
bin/        dev/        etc/        lib/        media/      opt/        root/       sbin/       sys/        usr/        
boot/       .dockerenv  home/       lib64/      mnt/        proc/       run/        srv/        tmp/        var/        

[root@master d37ff828e6308...0c0599b]# 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 d37ff828e6308...0c0599b]# 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 d37ff828e6308...0c0599b]# 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 d37ff828e6308...0c0599b]# docker exec -it nginx2 bash
root@a9c9f31cdccf:/# head /etc/nginx/nginx.conf -n 3
user  nginx
worker_processes  1

3, 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 (然后systemctl reload docker)

#方式1:
[root@c7 ~]# cat /etc/docker/daemon.json 
{
 "data-root":"/export/lib/docker/"
}

#方式2:
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
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