docker安装并设置开机启动（CentOS7/8）

CentOS7.2

docker分为CE和EE版本，EE版本收费，一般我们使用CE版本就满足要求了

docker安装及启动

docker安装很简单，直接使用如下命令安装即可，安装后的docker版本即为CE免费版(对于更高的linux版本，可以先执行安装docker-ce,如果提示Nothing to do，则再直接使用如下命令)

yum -y install docker

安装结束后，查看docker运行状态

启动docker

查看/var/log/messages日志，扎到如下错误信息

Aug 12 19:29:14 localhost dockerd-current: Error starting daemon: SELinux is not supported with the overlay2 graph driver on this kernel. Either boot into a newer kernel or disable selinux in docker (--selinux-enabled=false)

根据错误提示，修改docker配置文件，设置--selinux-enabled=false

vim /etc/sysconfig/docker

保存后，重新启动docker，查看启动状态

设置docker开机启动

docker安装之后，已经安装了开机启动service文件，但还需要在设置下开机启动，才能在服务器重启时自动启动

systemctl enable docker

 CentOS8

查询docker

系统版本为Basic Web Server

[root@localhost ~]# yum search docker
Last metadata expiration check: 7:18:55 ago on Sun 13 Oct 2019 01:30:27 AM CST.
============================================================================== Summary & Name Matched: docker ===============================================================================
podman-docker.noarch : Emulate Docker CLI using podman
podman-docker.noarch : Emulate Docker CLI using podman
pcp-pmda-docker.x86_64 : Performance Co-Pilot (PCP) metrics from the Docker daemon
================================================================================== Summary Matched: docker ==================================================================================
oci-umount.x86_64 : OCI umount hook for docker
oci-systemd-hook.x86_64 : OCI systemd hook for docker
oci-systemd-hook.x86_64 : OCI systemd hook for docker
skopeo.x86_64 : Inspect Docker images and repositories on registries

这里没有我们想要的docker-ce

下载docker-ce repo

curl https://download.docker.com/linux/centos/docker-ce.repo -o /etc/yum.repos.d/docker-ce.repo

安装docker

[root@localhost ~]# yum -y install docker-ce
Docker CE Stable - x86_64                                                                                                                                    6.5 kB/s |  20 kB     00:03    
Error: 
 Problem: package docker-ce-3:19.03.3-3.el7.x86_64 requires containerd.io >= 1.2.2-3, but none of the providers can be installed
  - cannot install the best candidate for the job
  - package containerd.io-1.2.10-3.2.el7.x86_64 is excluded
  - package containerd.io-1.2.2-3.3.el7.x86_64 is excluded
  - package containerd.io-1.2.2-3.el7.x86_64 is excluded
  - package containerd.io-1.2.4-3.1.el7.x86_64 is excluded
  - package containerd.io-1.2.5-3.1.el7.x86_64 is excluded
  - package containerd.io-1.2.6-3.3.el7.x86_64 is excluded
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

提示信息中告诉我们需要containerd.io依赖

yum -y install https://download.docker.com/linux/fedora/30/x86_64/stable/Packages/containerd.io-1.2.6-3.3.fc30.x86_64.rpm

再次安装docker（如果在安装docker-ce repo之前执行过yum -y install docker，则需要先执行yum remove docker卸载）

yum -y install docker-ce

启动docker

systemctl start docker

加入开机启动

systemctl enable docker
systemctl daemon-reload

查看docker版本

[root@localhost ~]# docker version
Client: Docker Engine - Community
 Version:           19.03.3
 API version:       1.40
 Go version:        go1.12.10
 Git commit:        a872fc2f86
 Built:             Tue Oct  8 00:58:10 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.3
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.12.10
  Git commit:       a872fc2f86
  Built:            Tue Oct  8 00:56:46 2019
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.2.6
  GitCommit:        894b81a4b802e4eb2a91d1ce216b8817763c29fb
 runc:
  Version:          1.0.0-rc8
  GitCommit:        425e105d5a03fabd737a126ad93d62a9eeede87f
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

到此docker就安装完成了