docker学习(一)

atomic使用有点费劲，我改为centos7来做为学习环境。

1 安装

epel源就自带，目前版本是1.10.3

yum -y install docker

docker version
Client:
 Version:         1.10.3
 API version:     1.22
 Package version: docker-common-1.10.3-46.el7.centos.10.x86_64
 Go version:      go1.6.3
 Git commit:      d381c64-unsupported
 Built:           Thu Aug  4 13:21:17 2016
 OS/Arch:         linux/amd64

Server:
 Version:         1.10.3
 API version:     1.22
 Package version: docker-common-1.10.3-46.el7.centos.10.x86_64
 Go version:      go1.6.3
 Git commit:      d381c64-unsupported
 Built:           Thu Aug  4 13:21:17 2016
 OS/Arch:         linux/amd64

2 使用加速器下载镜像

国内访问docker.io剧慢，好在daocloud有号称终身免费的加速器，使用方法如下

curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://682e782c.m.daocloud.io

不过这条命令运行后加速没什么效果，因为set_mirror.sh脚本有问题

        if grep "CentOS Linux release 7" /etc/redhat-release > /dev/null
        then
            if [[ "$docker_version" -lt 12 ]]
            then 
                sudo sed -i "s|ExecStart=/usr/bin/docker daemon|ExecStart=/usr/bin/docker daemon --registry-mirror="$MIRROR_URL"|g" /lib/systemd/system/docker.service
                sudo systemctl daemon-reload
            else
                sudo sed -i "s|^ExecStart=/usr/bin/dockerd$|ExecStart=/usr/bin/dockerd --registry-mirror="$MIRROR_URL"|g" /lib/systemd/system/docker.service
                sudo systemctl daemon-reload
            fi
        echo "Success."
        echo "You need to restart docker to take effect : sudo systemctl restart docker "
                exit 0
        else
            echo "Error: Set mirror failed, please set registry-mirror manually please."
            exit 1
        fi  

脚本里是ExecStart=/usr/bin/docker daemon，docker.servicej里实际是ExecStart=/usr/bin/docker-current daemon，所以在后面手工加上--registry-'mirror=http://682e782c.m.daocloud.io'

更改完后，别忘记执行

systemctl daemon-reload
systemctl restart docker && systemctl enable docker

3 下载镜像

docker pull centos:6
Trying to pull repository docker.io/library/centos ... 
6: Pulling from docker.io/library/centos
08a7a0bb6122: Pull complete 
Digest: sha256:cd6d68000b47a91e7c94b558d7e3e653c3f0eac1a77842d97b0b7ad955cad608
Status: Downloaded newer image for docker.io/centos:6

docker pull centos:7
Trying to pull repository docker.io/library/centos ... 
7: Pulling from docker.io/library/centos
3d8673bd162a: Pull complete 
Digest: sha256:a66ffcb73930584413de83311ca11a4cb4938c9b2521d331026dad970c19adf4
Status: Downloaded newer image for docker.io/centos:7

docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
docker.io/centos    6                   a3c09d36ab4a        3 weeks ago         194.6 MB
docker.io/centos    7                   970633036444        3 weeks ago         196.7 MB

4 建立交互型容器

docker run -i -t centos:6 /bin/bash

[root@cab9ff817b6b /]# hostname
cab9ff817b6b

[root@cab9ff817b6b /]# cat /etc/hosts
...
172.17.0.2	cab9ff817b6b

[root@cab9ff817b6b /]# ifconfig 
eth0      Link encap:Ethernet  HWaddr 02:42:AC:11:00:02  
          inet addr:172.17.0.2  Bcast:0.0.0.0  Mask:255.255.0.0
          inet6 addr: fe80::42:acff:fe11:2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:648 (648.0 b)  TX bytes:648 (648.0 b)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 

[root@cab9ff817b6b /]# yum install vim 

[root@cab9ff817b6b /]# exit

docker run --name web-01 -i -t centos:6 /bin/bash

5 启动容器

docker start cab9ff817b6b
cab9ff817b6b

docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
cab9ff817b6b        centos:6            "/bin/bash"         6 minutes ago       Up 4 seconds                            suspicious_bose

docker attach cab9ff817b6b
附着容器，可以理解登录容器的交互界面

6 建立守护型容器

docker run --name test_01 -d centos:6 /bin/sh -c 'while true; do echo hello world; sleep 1; done'
c7d4781438a7a83d51324c0f2ed1237ab8a61a7b64911f20bc99ceeaf4e27955

docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
c7d4781438a7        centos:6            "/bin/sh -c 'while tr"   9 seconds ago       Up 7 seconds                            test_01

docker rm c7d4781438a7
Failed to remove container (c7d4781438a7): Error response from daemon: Conflict, You cannot remove a running container. Stop the container before attempting removal or use -f

docker stop c7d4781438a7
c7d4781438a7

docker rm c7d4781438a7
c7d4781438a7

7 容器状态

docker top fb6b7ef0ef52
UID                 PID                 PPID                C                   STIME               TTY                 TIME                CMD
root                22974               21672               1                   03:12               ?                   00:00:00            /bin/sh -c while true; do echo hello world; sleep 1; done
root                23031               22974               0                   03:12               ?                   00:00:00            sl

docker logs fb6b7ef0ef52

docker logs -f fb6b7ef0ef52

8 在容器内部运行进程

docker exec -d fb6b7ef0ef52 touch /etc/new_config_file

docker exec -i -t fb6b7ef0ef52 /bin/bash
[root@fb6b7ef0ef52 /]# ls /etc/new_config_file 
/etc/new_config_file

8 自动重启容器

docker run --restart=always --name test_01 -d centos:6 /bin/sh -c 'while true; do echo hello world; sleep 1; done'
或者异常退出，自动重启5次
--restart=on-failure:5

9 获取更多容器信息

docker inspect fb6b7ef0ef52
docker inspect --format '{{.Name}} {{.State.Running}}' fb6b7ef0ef52
/test_01 true

杀死所有running状态的容器
docker kill $(docker ps -q)

删除所有已经停止的容器
docker rm $(docker ps -a -q)

删除所有’untagged/dangling’ ()状态的镜像
docker rmi $(docker images -q -f dangling=true)

删除所有镜像：
docker rmi $(docker images -q)