Docker快速安装与快速入门

一、软件版本

操作系统：Centos 7.0

二、开始安装：

http://www.daocloud.io/
由于国内的源比较卡，所以我们推荐使用daocloud的方式，注册安装即可：

[root@localhost ~]# curl -sSL https://get.daocloud.io/docker | sh

为了快速拉取镜像，还要接daocloud.因为在国内通常拉取Docker hub的镜像都是被墙的。

[root@localhost ~]# curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://681a96df.m.daocloud.io
docker version >= 1.12
{"registry-mirrors": ["http://681a96df.m.daocloud.io"],"live-restore": true
}
Success.
You need to restart docker to take effect: sudo systemctl restart docker

实际上是相关配置写入了，

[root@localhost ~]# cat /etc/docker/daemon.json
{"registry-mirrors": ["http://681a96df.m.daocloud.io"],"live-restore": true
}

指定去这个仓库下，因为默认是去官方的Docker hub下载镜像的。
然后重启docker:

systemctl restart docker

ExecStart=/usr/bin/dockerd -H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375  ##tcp

2、我们也可以看一下到底docker 读取的是哪个配置文件，不同版本可能不一样：

[root@localhost ~]# systemctl status docker
● docker.service - Docker Application Container EngineLoaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)Active: active (running) since 六 2018-08-18 11:46:11 CST; 42s agoDocs: https://docs.docker.comMain PID: 40649 (dockerd)Tasks: 29Memory: 47.4MCGroup: /system.slice/docker.service├─40649 /usr/bin/dockerd└─40657 docker-containerd --config /var/run/docker/containerd/containerd.toml8月 18 11:46:10 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:10.860628488+08:00" level=info msg="pickfirstBalancer:...e=grpc
8月 18 11:46:10 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:10.860794413+08:00" level=info msg="pickfirstBalancer:...e=grpc
8月 18 11:46:10 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:10.860811302+08:00" level=info msg="Loading containers: start."
8月 18 11:46:11 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:11.113070064+08:00" level=info msg="Default bridge (do...dress"
8月 18 11:46:11 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:11.164857941+08:00" level=info msg="Loading containers: done."
8月 18 11:46:11 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:11.181541949+08:00" level=info msg="Docker daemon" com...6.0-ce
8月 18 11:46:11 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:11.181666174+08:00" level=info msg="Daemon has complet...ation"
8月 18 11:46:11 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:11.189756196+08:00" level=warning msg="Could not regis...$PATH"
8月 18 11:46:11 localhost.localdomain dockerd[40649]: time="2018-08-18T11:46:11.195308654+08:00" level=info msg="API listen on /var....sock"
8月 18 11:46:11 localhost.localdomain systemd[1]: Started Docker Application Container Engine.
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost ~]#

这里我们知道centos读取的是/usr/lib/systemd/system/docker.service这个文件。启动的相关参数，后面再慢慢开始

Tcp:
Vim /usr/lib/systemd/system/docker.service

[root@master ~]# docker -H 192.168.63.200:2375 images

三、开始基本操作：

1、查看有没有镜像：

[root@localhost ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
upstram_nginx       latest              f3c5dcc79825        8 days ago          669 MB
lnmp/nginx          0.2                 9fe8cdcb3e43        8 days ago          669 MB

一个镜像的标识由仓库信息+tag构成
比方说我们启动可以用Image ID来标识，或者lnmp/nginx:0.2这样标识，不写后面默认是lastest

2、有镜像之后我们可以启动一个容器：

[root@localhost ~]# docker run -dit -P nginx
Unable to find image 'nginx:latest' locally
latest: Pulling from library/nginx
be8881be8156: Pull complete
32d9726baeef: Pull complete
87e5e6f71297: Pull complete
Digest: sha256:4ffd9758ea9ea360fd87d0cee7a2d1cf9dba630bb57ca36b3108dcd3708dc189
Status: Downloaded newer image for nginx:latest
cf05d1459d716965c21e8c30fff3dede10744029cbc46db4620e532789762448
[root@localhost ~]#

docker run 后面常用选项：

--name:指定容器名称
-P：随机映射端口
-v:实现文件或者目录挂载
-i:交互
-t:tty

我们启动一个容器，默认没有指定后面的tag标签就是变成：nginx:latest，然后我们可以看到本地没有镜像的话就会去远端的Docker hub下载。

3、查看一下docker 当前运行有哪些镜像：

[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                   NAMES
cf05d1459d71        nginx               "nginx -g 'daemon of…"   2 minutes ago       Up 2 minutes        0.0.0.0:32768->80/tcp   serene_boyd
[root@localhost ~]#

当容器停止之后，我们需要用docker ps –a来查看所有镜像。

可以看到当前运行一个nginx的镜像，名称因为我们没有指定是随机起的叫gifted_aryabhata。然后nginx 的80端口映射到本机的32768端口。

4、测试一下：

[root@localhost ~]# curl 127.0.0.1:32768
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>body {width: 35em;margin: 0 auto;font-family: Tahoma, Verdana, Arial, sans-serif;}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p><p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p><p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@localhost ~]#

可以看到是能够访问的。

5、我们可以查看相关容器的日志：

[root@localhost ~]# docker logs cf05d1459d71
172.17.0.1 - - [18/Aug/2018:04:00:05 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.29.0" "-"
[root@localhost ~]#

6、当然我们也可以登录容器：

[root@localhost ~]# docker exec -it cf05d1459d71 /bin/bash
root@cf05d1459d71:/#