请在“/etc/apt/sources.list”文件中的检查源是否正确，如果没有配置源，请配置可用的源。
用户也可以登录源链接，根据现场操作系统架构和版本，进入对应操作系统目录，单击打开“source.list”文件，将文件内源链接复制到服务器“/etc/apt/sources.list”文件中，要包含Docker-ce相关的源，如“deb https://mirrors.huaweicloud.com/docker-ce/linux/ubuntu/focal stable”。

以下介绍安装Docker的方法：

以root用户登录服务器，配置信任Docker的GPG公钥，命令如下：

curl -fsSL https://repo.huaweicloud.com/docker-ce/linux/debian/gpg | sudo apt-key add -

执行以下命令，更新源并安装Docker。

apt-get update 
apt-get install -y docker-ce

如果执行apt-get update命令时，出现类似如下所示报错，则执行apt-get update --allow-unauthenticated命令。

Err:1 https://repo.huaweicloud.com/docker-ce/linux/ubuntu focal InRelease  Temporary failure resolving 'repo.huaweicloud.com'
Err:2 https://mirrors.huaweicloud.com/ubuntu-ports focal InRelease  Temporary failure resolving 'mirrors.huaweicloud.com'
Err:3 https://mirrors.huaweicloud.com/ubuntu-ports focal-updates InRelease Temporary failure resolving 'mirrors.huaweicloud.com'
Err:4 https://mirrors.huaweicloud.com/ubuntu-ports focal-security InRelease Temporary failure resolving 'mirrors.huaweicloud.com'
Err:5 https://mirrors.huaweicloud.com/docker-ce/linux/ubuntu focal InRelease Temporary failure resolving 'mirrors.huaweicloud.com'
Reading package lists... Done
N: Ignoring file 'index.html' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension
W: Failed to fetch https://mirrors.huaweicloud.com/ubuntu-ports/dists/focal/InRelease  Temporary failure resolving 'mirrors.huaweicloud.com'
W: Failed to fetch https://mirrors.huaweicloud.com/ubuntu-ports/dists/focal-updates/InRelease  Temporary failure resolving 'mirrors.huaweicloud.com'
W: Failed to fetch https://mirrors.huaweicloud.com/ubuntu-ports/dists/focal-security/InRelease  Temporary failure resolving 'mirrors.huaweicloud.com'
W: Failed to fetch https://mirrors.huaweicloud.com/docker-ce/linux/ubuntu/dists/focal/InRelease  Temporary failure resolving 'mirrors.huaweicloud.com'
W: Failed to fetch https://repo.huaweicloud.com/docker-ce/linux/ubuntu/dists/focal/InRelease  Temporary failure resolving 'repo.huaweicloud.com'
W: Some index files failed to download. They have been ignored, or old ones used instead.

执行systemctl start docker命令启动Docker。

执行docker version命令，如回显类似以下信息表示Docker已安装并启动。

Client: Docker Engine - Community
 Version:           20.10.7
 API version:       1.41
 Go version:        go1.13.15
 Git commit:        f0df350
 Built:             Wed Jun 30 19:55:49 2021
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.7
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       b0f5bc3
  Built:            Wed Jun 30 19:54:13 2021
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.4.9
  GitCommit:        e25210fe30a0a703442421b0f60afac609f950a3
 runc:
  Version:          1.0.1
  GitCommit:        v1.0.1-0-g4144b63
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

部署Docker（Ubuntu）