官方文档 推荐使用docker自己的apt源，不使用Ubuntu自带的docker源。

Ubuntu自带docker包卸载

sudo apt-get remove docker docker-engine docker.io containerd runc

更新系统 安装辅助工具

sudo apt-get update
sudo apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg \
    lsb-release

添加docker官方的GPG key:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

添加docker源

x86_64 源

echo \
  "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

arm64源

echo \
  "deb [arch=arm64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

从官方源安装docker

sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io

helloworld测试

sudo docker run hello-world

错误解决

不明原因的情况下遇到下面的错误：

Err:2 https://download.docker.com/linux/ubuntu focal InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7EA0A9C3F273FCD8

解决办法，不用key文件的方式

$ sudo rm /usr/share/keyrings/docker-archive-keyring.gpg
$ curl -fsSL https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu/gpg | sudo apt-key add -
$ sudo vim /etc/apt/sources.list.d/docker.list
deb [arch=arm64] https://download.docker.com/linux/ubuntu   focal stable