Centos下安裝docker

官方原文連接 https://docs.docker.com/engine/installation/centos/

經過yum安裝

須要root或者能sudo的權限

yum包更新到最新

$ sudo yum update

添加Docker yum源

$ sudo tee /etc/yum.repos.d/docker.repo <<-'EOF'
[dockerrepo]
name=Docker Repository
baseurl=https://yum.dockerproject.org/repo/main/centos/$releasever/
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg
EOF

安裝Docker包

$ sudo yum install docker-engine

啓動Docker守護進程

$ sudo service docker start

經過測試鏡像運行一個容器來驗證Docker是否安裝正確

$ sudo docker run hello-world
Unable to find image 'hello-world:latest' locally
    latest: Pulling from hello-world
    a8219747be10: Pull complete
    91c95931e552: Already exists
    hello-world:latest: The image you are pulling has been verified. Important: image verification is a tech preview feature and should not be relied on to provide security.
    Digest: sha256:aa03e5d0d5553b4c3473e89c8619cf79df368babd1.7.1cf5daeb82aab55838d
    Status: Downloaded newer image for hello-world:latest
    Hello from Docker.
    This message shows that your installation appears to be working correctly.


    To generate this message, Docker took the following steps:
     1. The Docker client contacted the Docker daemon.
     2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
            (Assuming it was not already locally available.)
     3. The Docker daemon created a new container from that image which runs the
            executable that produces the output you are currently reading.
     4. The Docker daemon streamed that output to the Docker client, which sent it
            to your terminal.


    To try something more ambitious, you can run an Ubuntu container with:
     $ docker run -it ubuntu bash


    For more examples and ideas, visit:
     http://docs.docker.com/userguide/

經過腳本安裝

須要root或者能sudo的權限

yum包更新到最新

$ sudo yum update

運行Docker安裝腳本

$ curl -sSL https://get.docker.com/ | sh

這個腳本會添加docker.repo倉庫而且安裝Docker

啓動Docker守護進程

$ sudo service docker start

經過測試鏡像運行一個容器來驗證Docker是否安裝正確

$ sudo docker run hello-world

建立一個Docker用戶組

docker守護進程綁定在Unix socket 而不是 TCP 端口。默認狀況下Unix socket屬於root用戶和具備sudo權限用戶的使用範疇。出於這個緣由，docker守護進程須要一直在root用戶下面運行。

To avoid having to use sudo when you use the docker command, create a Unix group called docker and add users to it. When the docker daemon starts, it makes the ownership of the Unix socket read/writable by the docker group.

爲了不運行docker命令的時候須要使用sudo命令，建立一個叫docker的Unix用戶組並將須要運行docker的用戶添加進去。當開始運行docker守護進程，會令docker用戶組的成員擁有Unix socket的讀寫權限。

建立docker用戶組並添加用戶：

1. 須要root或者能sudo的權限

2. 建立docker用戶組並添加用戶

   sudo usermod -aG docker your_username

3. 退出而且登陸到your_username，若是在your_username下也建議退出再從新登陸一次，這確保您的用戶正在運行正確的權限。

4. 驗證運行docker已再也不須要sudo命令

   $ docker run hello-world

開機運行docker

$ sudo chkconfig docker on