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

sudo yum install -y yum-utils \device-mapper-persistent-data \lvm2

sudo yum-config-manager \--add-repo \https://download.docker.com/linux/centos/docker-ce.repo

会报以下错误：
Loaded plugins: fastestmirror
adding repo from: https://download.docker.com/linux/centos/docker-ce.repo
grabbing file https://download.docker.com/linux/centos/docker-ce.repo to /etc/yum.repos.d/docker-ce.repo
Could not fetch/save url https://download.docker.com/linux/centos/docker-ce.repo to file /etc/yum.repos.d/docker-ce.repo
: [Errno 14] curl#35 - "TCP connection reset by peer

sudo yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

出现以下内容则表示docker仓库配置成功：
Loaded plugins: fastestmirror
adding repo from: http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
grabbing file http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo to /etc/yum.repos.d/docker-ce.repo
repo saved to /etc/yum.repos.d/docker-ce.repo

sudo yum install docker-ce

出现以下异常：
Loaded plugins: fastestmirror
base
https://download-stage.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#35 - "TCP connection reset by peer"
Trying other mirror.One of the configured repositories failed (Docker CE Stable - x86_64),and yum doesn't have enough cached data to continue. At this point the onlysafe thing yum can do is fail. There are a few ways to work "fix" this:1. Contact the upstream for the repository and get them to fix the problem.2. Reconfigure the baseurl/etc. for the repository, to point to a workingupstream. This is most often useful if you are using a newerdistribution release than is supported by the repository (and thepackages for the previous distribution release still work).3. Run the command with the repository temporarily disabledyum --disablerepo=docker-ce-stable ...4. Disable the repository permanently, so yum won't use it by default. Yumwill then just ignore the repository until you permanently enable itagain or use --enablerepo for temporary usage:yum-config-manager --disable docker-ce-stableorsubscription-manager repos --disable=docker-ce-stable5. Configure the failing repository to be skipped, if it is unavailable.Note that yum will try to contact the repo. when it runs most commands,so will have to try and fail each time (and thus. yum will be be muchslower). If it is a very temporary problem though, this is often a nicecompromise:yum-config-manager --save --setopt=docker-ce-stable.skip_if_unavailable=truefailure: repodata/repomd.xml from docker-ce-stable: [Errno 256] No more mirrors to try.
https://download-stage.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#35 - "TCP connection reset by peer"

sudo vim /etc/yum.repos.d/docker-ce.repo

sudo yum install docker-ce

Installed:docker-ce.x86_64 0:18.03.0.ce-1.el7.centosDependency Installed:audit-libs-python.x86_64 0:2.7.6-3.el7 checkpolicy.x86_64 0:2.5-4.el7   container-selinux.noarch 2:2.42-1.gitad8f0f7.el7 libcgroup.x86_64 0libtool-ltdl.x86_64 0:2.4.2-22.el7_3   pigz.x86_64 0:2.3.3-1.el7.centos policycoreutils-python.x86_64 0:2.5-17.1.el7     python-IPy.noarchComplete!

sudo systemctl start docker

sudo docker run hello-world

Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
9bb5a5d4561a: Pulling fs layer
docker: error pulling image configuration: Get https://dseasb33srnrn.cloudfront.net/registry-v2/docker/registry/v2/blobs/sha256/e3/e38bc07ac18e
See 'docker run --help'.

vi /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd --registry-mirror=http://f2d6cb40.m.daocloud.io
ExecReload=/bin/kill -s HUP $MAINPID
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Uncomment TasksMax if your systemd version supports it.
# Only systemd 226 and above support this version.
#TasksMax=infinity
TimeoutStartSec=0
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process
# restart the docker process if it exits prematurely
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s[Install]
WantedBy=multi-user.target

$ sudo systemctl daemon-reload
$ sudo systemctl restart docker

sudo docker run hello-world

Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
9bb5a5d4561a: Pull complete
Digest: sha256:f5233545e43561214ca4891fd1157e1c3c563316ed8e237750d59bde73361e77
Status: Downloaded newer image for hello-world:latestHello 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.(amd64)3. The Docker daemon created a new container from that image which runs theexecutable that produces the output you are currently reading.4. The Docker daemon streamed that output to the Docker client, which sent itto your terminal.To try something more ambitious, you can run an Ubuntu container with:$ docker run -it ubuntu bashShare images, automate workflows, and more with a free Docker ID:https://hub.docker.com/

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