安装程序，报connect (101: Network is unreachable) Connection refused

1.安装docker 过程中报错

Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::15). - connect (101: Network is unreachable) Cannot initiate the connection to us.archive.ubuntu.com:80 (2001:67c:1562::18). - connect (101: Network is unreachable) Could not connect to us.archive.ubuntu.com:80 (91.189.91.38). - connect (111: Connection refused) Could not connect to us.archive.ubuntu.com:80 (91.189.91.39). - connect (111: Connection refused)
2.先设置代理

# 先设置代理
export http_proxy=http://:
export https_proxy=http://:
# 执行命令 `sudo add-apt-repository` 的时候加上 `-E`
sudo -E add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"

3.如下设置：

export http_proxy=http://us.archive.ubuntu.com:80

export https_proxy=http://us.archive.ubuntu.com:80

4.再次执行sudo apt install apt-transport-https ca-certificates curl software-properties-common成功