安裝Docker：

yum install docker-ce

出現錯誤如下：

Error: 
 Problem: problem with installed package buildah-1.11.6-7.module_el8.2.0+305+5e198a41.x86_64
  - package buildah-1.11.6-7.module_el8.2.0+305+5e198a41.x86_64 requires runc >= 1.0.0-26, but none of the providers can be installed
  - package containerd.io-1.3.7-3.1.el8.x86_64 conflicts with runc provided by runc-1.0.0-65.rc10.module_el8.2.0+305+5e198a41.x86_64
  - package containerd.io-1.3.7-3.1.el8.x86_64 obsoletes runc provided by runc-1.0.0-65.rc10.module_el8.2.0+305+5e198a41.x86_64
  - package docker-ce-3:19.03.13-3.el8.x86_64 requires containerd.io >= 1.2.2-3, but none of the providers can be installed
  - conflicting requests
  - package runc-1.0.0-56.rc5.dev.git2abd837.module_el8.2.0+303+1105185b.x86_64 is filtered out by modular filtering
  - package runc-1.0.0-64.rc10.module_el8.2.0+304+65a3c2ac.x86_64 is filtered out by modular filtering
(try to add '--allowerasing' to command line to replace conflicting packages or '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

解決辦法：

輸入下面的命令繼續安裝：

yum install --allowerasing docker-ce

安裝完成（最後顯示Complete！）：

[root@localhost leeho]# yum install --allowerasing docker-ce
Last metadata expiration check: 0:02:00 ago on Fri 13 Nov 2020 08:22:14 PM EST.
Dependencies resolved.
========================================================================================================================
 Package                Architecture    Version                                         Repository                 Size
========================================================================================================================
Installing:
 docker-ce              x86_64          3:19.03.13-3.el8                                docker-ce-stable           24 M
Installing dependencies:
 containerd.io          x86_64          1.3.7-3.1.el8                                   docker-ce-stable           29 M
     replacing  runc.x86_64 1.0.0-65.rc10.module_el8.2.0+305+5e198a41
 docker-ce-cli          x86_64          1:19.03.13-3.el8                                docker-ce-stable           38 M
 libcgroup              x86_64          0.41-19.el8                                     BaseOS                     70 k
Removing dependent packages:
 buildah                x86_64          1.11.6-7.module_el8.2.0+305+5e198a41            @AppStream                 35 M

Transaction Summary
========================================================================================================================
Install  4 Packages
Remove   1 Package

Total download size: 92 M
Is this ok [y/N]: y
Downloading Packages:
(1/4): libcgroup-0.41-19.el8.x86_64.rpm                                                 393 kB/s |  70 kB     00:00    
(2/4): docker-ce-19.03.13-3.el8.x86_64.rpm                                              2.9 MB/s |  24 MB     00:08    
(3/4): docker-ce-cli-19.03.13-3.el8.x86_64.rpm                                          2.3 MB/s |  38 MB     00:16    
(4/4): containerd.io-1.3.7-3.1.el8.x86_64.rpm                                           1.1 MB/s |  29 MB     00:25    
------------------------------------------------------------------------------------------------------------------------
Total                                                                                   3.4 MB/s |  92 MB     00:26     
warning: /var/cache/dnf/docker-ce-stable-fa9dc42ab4cec2f4/packages/containerd.io-1.3.7-3.1.el8.x86_64.rpm: Header V4 RSA/SHA512 Signature, key ID 621e9f35: NOKEY
Docker CE Stable - x86_64                                                               2.8 kB/s | 1.6 kB     00:00    
Importing GPG key 0x621E9F35:
 Userid     : "Docker Release (CE rpm) <docker@docker.com>"
 Fingerprint: 060A 61C5 1B55 8A7F 742B 77AA C52F EB6B 621E 9F35
 From       : https://download.docker.com/linux/centos/gpg
Is this ok [y/N]: y
Key imported successfully
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                                1/1 
  Installing       : docker-ce-cli-1:19.03.13-3.el8.x86_64                                                          1/6 
  Running scriptlet: docker-ce-cli-1:19.03.13-3.el8.x86_64                                                          1/6 
  Installing       : containerd.io-1.3.7-3.1.el8.x86_64                                                             2/6 
  Running scriptlet: containerd.io-1.3.7-3.1.el8.x86_64                                                             2/6 
  Running scriptlet: libcgroup-0.41-19.el8.x86_64                                                                   3/6 
  Installing       : libcgroup-0.41-19.el8.x86_64                                                                   3/6 
  Running scriptlet: libcgroup-0.41-19.el8.x86_64                                                                   3/6 
  Installing       : docker-ce-3:19.03.13-3.el8.x86_64                                                              4/6 
  Running scriptlet: docker-ce-3:19.03.13-3.el8.x86_64                                                              4/6 
  Erasing          : buildah-1.11.6-7.module_el8.2.0+305+5e198a41.x86_64                                            5/6 
  Obsoleting       : runc-1.0.0-65.rc10.module_el8.2.0+305+5e198a41.x86_64                                          6/6 
  Running scriptlet: runc-1.0.0-65.rc10.module_el8.2.0+305+5e198a41.x86_64                                          6/6 
  Verifying        : libcgroup-0.41-19.el8.x86_64                                                                   1/6 
  Verifying        : containerd.io-1.3.7-3.1.el8.x86_64                                                             2/6 
  Verifying        : runc-1.0.0-65.rc10.module_el8.2.0+305+5e198a41.x86_64                                          3/6 
  Verifying        : docker-ce-3:19.03.13-3.el8.x86_64                                                              4/6 
  Verifying        : docker-ce-cli-1:19.03.13-3.el8.x86_64                                                          5/6 
  Verifying        : buildah-1.11.6-7.module_el8.2.0+305+5e198a41.x86_64                                            6/6 
Installed products updated.

Installed:
  containerd.io-1.3.7-3.1.el8.x86_64     docker-ce-3:19.03.13-3.el8.x86_64     docker-ce-cli-1:19.03.13-3.el8.x86_64    
  libcgroup-0.41-19.el8.x86_64          

Removed:
  buildah-1.11.6-7.module_el8.2.0+305+5e198a41.x86_64                                                                   

Complete!

輸入以下命令檢視docker版本號：

docker version

顯示為：

Client: Docker Engine - Community
 Version:           19.03.13
 API version:       1.40
 Go version:        go1.13.15
 Git commit:        4484c46d9d
 Built:             Wed Sep 16 17:02:36 2020
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.13
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       4484c46d9d
  Built:            Wed Sep 16 17:01:11 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.3.7
  GitCommit:        8fba4e9a7d01810a393d5d25a3621dc101981175
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683