一、安装步骤
- 首先卸载老版本的docker：
sudo yum remove docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine
2. 安装yum-utils软件包（提供yum-config-manager 实用程序）并设置yum存储库。
sudo yum install -y yum-utils
sudo yum-config-manager
--add-repo
https://download.docker.com/linux/centos/docker-ce.repo
3. 安装最新版本的Docker Engine和容器：
[root@localhost yum.repos.d]# yum install docker-ce docker-ce-cli containerd.io Repository extras is listed more than once in the configuration Last metadata expiration check: 0:03:34 ago on Wed 31 Mar 2021 01:59:56 AM EDT. Error: Problem 1: problem with installed package podman-2.0.5-5.module_el8.3.0+512+b3b58dca.x86_64 - package podman-2.0.5-5.module_el8.3.0+512+b3b58dca.x86_64 requires runc >= 1.0.0-57, but none of the providers can be installed - package podman-2.2.1-7.module_el8.3.0+699+d61d9c41.x86_64 requires runc >= 1.0.0-57, but none of the providers can be installed - package containerd.io-1.4.4-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64 - package containerd.io-1.4.4-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64 - package containerd.io-1.4.4-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64 - package containerd.io-1.4.4-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64 - cannot install the best candidate for the job - package runc-1.0.0-64.rc10.module_el8.3.0+479+69e2ae26.x86_64 is filtered out by modular filtering Problem 2: problem with installed package podman-catatonit-2.0.5-5.module_el8.3.0+512+b3b58dca.x86_64 - package podman-catatonit-2.2.1-7.module_el8.3.0+699+d61d9c41.x86_64 requires podman = 2.2.1-7.module_el8.3.0+699+d61d9c41, but none of the providers can be installed - package podman-2.2.1-7.module_el8.3.0+699+d61d9c41.x86_64 requires runc >= 1.0.0-57, but none of the providers can be installed - package containerd.io-1.4.3-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64 - package containerd.io-1.4.3-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64 - package docker-ce-3:20.10.5-3.el8.x86_64 requires containerd.io >= 1.4.1, but none of the providers can be installed - package containerd.io-1.4.3-3.2.el8.x86_64 conflicts with runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64 - package containerd.io-1.4.3-3.2.el8.x86_64 obsoletes runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64 - package containerd.io-1.4.3-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64 - package containerd.io-1.4.3-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64 - package containerd.io-1.4.3-3.2.el8.x86_64 conflicts with runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64 - package containerd.io-1.4.3-3.2.el8.x86_64 obsoletes runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64 - package containerd.io-1.4.4-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64 - package containerd.io-1.4.4-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64
这是因为CentOS8默认采用podman，这里podman跟docker冲突，需要卸载podman。
[root@localhost yum.repos.d]# yum remove podman
然后再次执行安装：
[root@localhost yum.repos.d]# yum install docker-ce docker-ce-cli containerd.io
Repository extras is listed more than once in the configuration
Last metadata expiration check: 0:09:11 ago on Wed 31 Mar 2021 01:59:56 AM EDT.
Error:
Problem: problem with installed package buildah-1.15.1-2.module_el8.3.0+475+c50ce30b.x86_64
- package buildah-1.15.1-2.module_el8.3.0+475+c50ce30b.x86_64 requires runc >= 1.0.0-26, but none of the providers can be installed
- package buildah-1.16.7-4.module_el8.3.0+699+d61d9c41.x86_64 requires runc >= 1.0.0-26, but none of the providers can be installed
- package containerd.io-1.4.4-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64
- package containerd.io-1.4.4-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-68.rc92.module_el8.3.0+475+c50ce30b.x86_64
- package containerd.io-1.4.4-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64
- package containerd.io-1.4.4-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-70.rc92.module_el8.3.0+699+d61d9c41.x86_64
可以看到还是要报错，所以我们还需要卸载buildah，然后再安装。所以在CentOS8安装docker之前需要移除两个组件，如下：
[root@localhost yum.repos.d]# yum erase podman buildah
然后再进行安装：
[root@localhost yum.repos.d]# yum install docker-ce docker-ce-cli containerd.io
4. 启动docker：
[root@localhost yum.repos.d]# sudo systemctl start docker
5.测试“hello world”:
[root@localhost yum.repos.d]# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
b8dfde127a29: Pull complete
Digest: sha256:308866a43596e83578c7dfa15e27a73011bdd402185a84c5cd7f32a88b501a24
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.
(amd64)
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
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
6. 查看一下已有镜像，安装成功。
[root@localhost yum.repos.d]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest d1165f221234 3 weeks ago 13.3kB