[系统运维]Docker实践与命令

安装docker：

yum -y install docker

下载镜像：

docker search centos      　　　　   //搜索镜像

[root@192 docker]# docker pull centos:7.2.1511
Trying to pull repository docker.io/library/centos ... 
7.2.1511: Pulling from docker.io/library/centos
a8c7037c15e9: Pull complete 
Digest: sha256:50cca1e74da4b6a4eb4ade029c8fdd4ee8564776801914d9bd89df8c6344add0
Status: Downloaded newer image for docker.io/centos:7.2.1511

[root@192 docker]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
docker.io/centos    7.2.1511            9aec5c5fe4ba        3 years ago         195 MB

[root@192 docker]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

启动容器：
??因为是在1台虚拟机搭建3个docker的缘故，所以这次选择的docker 网卡类型为bridge模式（bridge模式容器ip无法自己指定），网段为 172.17.0.0/16 网关为172.17.0.1，三台容器的主机名和ip分别为：

server     172.17.0.2
agent1     172.17.0.3
agent2     172.17.0.4

# 开始启动3台容器：
[root@192 docker]# docker run -it -d --name server --network bridge --hostname server docker.io/centos:7.2.1511 /bin/bash
e35571a1261d70173ceb6ed33c84d04bf8b300c0fb073b23ac67afa335980b4f
[root@192 docker]# docker run -it -d --name agent1 --network bridge --hostname agent1 docker.io/centos:7.2.1511 /bin/bash
87fa9ab888066f45023999f77152df140a8b6d8b5b4dd47ce166bd7f99025a36
[root@192 docker]# docker run -it -d --name agent2 --network bridge --hostname agent2 docker.io/centos:7.2.1511 /bin/bash
8b685b1e4177f62bc74f4c535e1905298c09ed97ab520f43b9b6b82c01e51a21

# 查看容器并进入：
[root@192 docker]# docker ps
CONTAINER ID        IMAGE                       COMMAND             CREATED              STATUS              PORTS               NAMES
8b685b1e4177        docker.io/centos:7.2.1511   "/bin/bash"         About a minute ago   Up About a minute                       agent2
87fa9ab88806        docker.io/centos:7.2.1511   "/bin/bash"         2 minutes ago        Up 2 minutes                            agent1
e35571a1261d        docker.io/centos:7.2.1511   "/bin/bash"         2 minutes ago        Up 2 minutes                            server

# 进入容器：
[root@192 docker]# docker exec -it server /bin/bash
[root@server /]# 
# 可能遇到问题：
[root@192 ~]# docker exec -it server /bin/bash
Error response from daemon: Container e35571a1261d70173ceb6ed33c84d04bf8b300c0fb073b23ac67afa335980b4f is not running
# 解决：
[root@192 ~]# docker start server
server

重启docker服务：

[root@192 docker]# systemctl restart docker
[root@192 docker]# systemctl status docker
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: active (running) since Mon 2022-03-21 00:25:56 PDT; 28min ago
     Docs: http://docs.docker.com
 Main PID: 50766 (dockerd-current)
   Memory: 18.0M
   CGroup: /system.slice/docker.service
           ├─50766 /usr/bin/dockerd-current --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current --default-runtime=docker...
           ├─50776 /usr/bin/docker-containerd-current -l unix:///var/run/docker/libcontainerd/docker-containerd.sock --metrics-interva...
           ├─51467 /usr/bin/docker-containerd-shim-current e35571a1261d70173ceb6ed33c84d04bf8b300c0fb073b23ac67afa335980b4f /var/run/d...
           ├─51573 /usr/bin/docker-containerd-shim-current 87fa9ab888066f45023999f77152df140a8b6d8b5b4dd47ce166bd7f99025a36 /var/run/d...
           └─51665 /usr/bin/docker-containerd-shim-current 8b685b1e4177f62bc74f4c535e1905298c09ed97ab520f43b9b6b82c01e51a21 /var/run/d...

Mar 21 00:25:56 192.168.42.132 dockerd-current[50766]: time="2022-03-21T00:25:56.328358495-07:00" level=info msg="Firewalld runn...false"
Mar 21 00:25:56 192.168.42.132 dockerd-current[50766]: time="2022-03-21T00:25:56.436304532-07:00" level=info msg="Default bridge...dress"
Mar 21 00:25:56 192.168.42.132 dockerd-current[50766]: time="2022-03-21T00:25:56.588477237-07:00" level=info msg="Loading contai...done."
Mar 21 00:25:56 192.168.42.132 dockerd-current[50766]: time="2022-03-21T00:25:56.730061633-07:00" level=info msg="Daemon has com...ation"
Mar 21 00:25:56 192.168.42.132 dockerd-current[50766]: time="2022-03-21T00:25:56.730927542-07:00" level=info msg="Docker daemon"...1.13.1
Mar 21 00:25:56 192.168.42.132 systemd[1]: Started Docker Application Container Engine.
Mar 21 00:25:56 192.168.42.132 dockerd-current[50766]: time="2022-03-21T00:25:56.757134704-07:00" level=info msg="API listen on ....sock"
Mar 21 00:42:08 192.168.42.132 oci-umount[51500]: umounthook <debug>: prestart container_id:e35571a1261d rootfs:/var/lib/docker/...rootfs
Mar 21 00:42:21 192.168.42.132 dockerd-current[50766]: time="2022-03-21T00:42:21.421376820-07:00" level=error msg="Handler for POST /v...
Mar 21 00:42:50 192.168.42.132 oci-umount[51606]: umounthook <debug>: prestart container_id:87fa9ab88806 rootfs:/var/lib/docker/...rootfs
Hint: Some lines were ellipsized, use -l to show in full.

重启过程中遇到的问题：

[root@192 docker]# systemctl restart docker.service
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.

# 解决：修改这两个配置文件后重启docker即可（来自：https://www.cnblogs.com/lhd1998/p/13361739.html?utm_source=tuicool）
vim /etc/sysconfig/docker-storage
DOCKER_STORAGE_OPTIONS="--selinux-enabled --log-driver=journald --signature-verification=false"

vim /etc/docker/daemon.json
{ "storage-driver": "devicemapper" }

将本地文件上传到docker容器中：

[root@192 ~]# docker inspect -f '{{.ID}}' e35571a1261d
e35571a1261d70173ceb6ed33c84d04bf8b300c0fb073b23ac67afa335980b4f
[root@192 ~]# docker cp /mnt/jdk-8u91-linux-x64.tar.gz e35571a1261d70173ceb6ed33c84d04bf8b300c0fb073b23ac67afa335980b4f:/mnt

删除容器：

[root@192 ~]# docker rm -f f46b3d7c8b51
f46b3d7c8b51