1、卸載老版本的Docker，沒有安裝則不卸載。

yum remove docker
                  docker-client
                  docker-client-latest
                  docker-common
                  docker-latest
                  docker-latest-logrotate
                  docker-logrotate
                  docker-selinux
                  docker-engine-selinux
                  docker-engine

配置官方y(tǒng)um源，啟用穩(wěn)定版源配置。

[root@ChatDevOps-01 ~]# echo ‘[docker-ce-stable]
name=Docker CE Stable – $basearch
baseurl=https://download.docker.com/linux/CentOS/7/$basearch/stable
enabled=1
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-stable-debuginfo]
name=Docker CE Stable – Debuginfo $basearch
baseurl=https://download.docker.com/linux/centos/7/debug-$basearch/stable
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-stable-source]
name=Docker CE Stable – Sources
baseurl=https://download.docker.com/linux/centos/7/source/stable
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-edge]
name=Docker CE Edge – $basearch
baseurl=https://download.docker.com/linux/centos/7/$basearch/edge
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-edge-debuginfo]
name=Docker CE Edge – Debuginfo $basearch
baseurl=https://download.docker.com/linux/centos/7/debug-$basearch/edge
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-edge-source]
name=Docker CE Edge – Sources
baseurl=https://download.docker.com/linux/centos/7/source/edge
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-test]
name=Docker CE Test – $basearch
baseurl=https://download.docker.com/linux/centos/7/$basearch/test
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-test-debuginfo]
name=Docker CE Test – Debuginfo $basearch
baseurl=https://download.docker.com/linux/centos/7/debug-$basearch/test
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-test-source]
name=Docker CE Test – Sources
baseurl=https://download.docker.com/linux/centos/7/source/test
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-nightly]
name=Docker CE Nightly – $basearch
baseurl=https://download.docker.com/linux/centos/7/$basearch/nightly
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-nightly-debuginfo]
name=Docker CE Nightly – Debuginfo $basearch
baseurl=https://download.docker.com/linux/centos/7/debug-$basearch/nightly
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg

[docker-ce-nightly-source]
name=Docker CE Nightly – Sources
baseurl=https://download.docker.com/linux/centos/7/source/nightly
enabled=0
gpgcheck=1
gpgkey=https://download.docker.com/linux/centos/gpg’>/etc/yum.repos.d/docker-ce.repo

此步驟中，需要注意的是：要啟用哪個(gè)版本的源就將其下的enable值設(shè)置為1，其余設(shè)置為0。命令中的引號(hào)必須使用單引號(hào)。yum.repos.d目錄下的文件必須以.repo結(jié)尾。

查看當(dāng)前源的可用版本。

[root@ChatDevOps-01 ~]# yum list docker-ce –showduplicates|grep “^doc”|sort -r
docker-ce.x86_64            18.06.1.ce-3.el7                    docker-ce-stable
docker-ce.x86_64            18.06.0.ce-3.el7                    docker-ce-stable
docker-ce.x86_64            18.03.1.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            18.03.0.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.12.1.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.12.0.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.09.1.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.09.0.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.06.2.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.06.1.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.06.0.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.03.3.ce-1.el7                    docker-ce-stable
docker-ce.x86_64            17.03.2.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.03.1.ce-1.el7.centos            docker-ce-stable
docker-ce.x86_64            17.03.0.ce-1.el7.centos            docker-ce-stable

安裝docker-ce-18.06.0.ce-3.el7。若要安裝其他版本則按照以下格式進(jìn)行安裝：docker-ce-

[root@ChatDevOps-01 ~]# yum -y install docker-ce-18.06.0.ce-3.el7
[root@ChatDevOps-01 ~]# docker version
Client:
 Version:          18.06.0-ce
 API version:      1.38
 Go version:        go1.10.3
 Git commit:        0ffa825
 Built:            Wed Jul 18 19:08:18 2018
 OS/Arch:          linux/amd64
 Experimental:      false
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

啟動(dòng)docker服務(wù)。

[root@ChatDevOps-01 ~]# systemctl status docker
● docker.service – Docker Application Container Engine
  Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
  Active: inactive (dead)
    Docs: https://docs.docker.com
12345
[root@ChatDevOps-01 ~]# systemctl start docker
[root@ChatDevOps-01 ~]# docker version
Client:
 Version:          18.06.0-ce
 API version:      1.38
 Go version:        go1.10.3
 Git commit:        0ffa825
 Built:            Wed Jul 18 19:08:18 2018
 OS/Arch:          linux/amd64
 Experimental:      false

Server:
 Engine:
  Version:          18.06.0-ce
  API version:      1.38 (minimum version 1.12)
  Go version:      go1.10.3
  Git commit:      0ffa825
  Built:            Wed Jul 18 19:10:42 2018
  OS/Arch:          linux/amd64
  Experimental:    false

將docker服務(wù)設(shè)置為開機(jī)啟動(dòng)。

[root@ChatDevOps-01 ~]# systemctl enable docker
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.

參考資料：
https://docs.docker.com/install/linux/docker-ce/centos/