一、安裝步驟
- 首先卸載老版本的docker：
sudo yum remove docker \ docker-client \ docker-client-latest \ docker-common \ docker-latest \ docker-latest-logrotate \ docker-logrotate \ docker-engine
2. 安裝yum-utils軟件包（提供yum-config-manager 實用程序）並設置yum存儲庫。
sudo yum install -y yum-utils
sudo yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
3. 安裝最新版本的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
這是因為CentOS8默認采用podman，這里podman跟docker沖突，需要卸載podman。
[root@localhost yum.repos.d]# yum remove podman
然后再次執行安裝：
[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
可以看到還是要報錯，所以我們還需要卸載buildah，然后再安裝。所以在CentOS8安裝docker之前需要移除兩個組件，如下：
[root@localhost yum.repos.d]# yum erase podman buildah
然后再進行安裝：
[root@localhost yum.repos.d]# yum install docker-ce docker-ce-cli containerd.io
4. 啟動docker：
[root@localhost yum.repos.d]# sudo systemctl start docker
5.測試“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. 查看一下已有鏡像，安裝成功。
[root@localhost yum.repos.d]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest d1165f221234 3 weeks ago 13.3kB