我尝试使用这里找到的官方分步页面在Ubuntu 18.04上安装Docker CE 18.03。我在步骤4）sudo apt-get update卡住了。这是我得到的：

Hit:1 http://mirror.transip.net/stack/software/deb/Ubuntu_18.04 ./ InRelease
Hit:2 http://nl.archive.ubuntu.com/ubuntu bionic InRelease 
Ign:3 http://dl.google.com/linux/chrome/deb stable InRelease 
Hit:4 http://dl.google.com/linux/chrome/deb stable Release 
Hit:5 http://nl.archive.ubuntu.com/ubuntu bionic-updates InRelease 
Hit:6 http://nl.archive.ubuntu.com/ubuntu bionic-backports InRelease 
Hit:7 http://security.ubuntu.com/ubuntu bionic-security InRelease 
Err:8 https://get.docker.com/ubuntu docker InRelease 
403 Forbidden [IP: 52.85.58.66 443]
Reading package lists... Done 
E: Failed to fetch http://get.docker.io/ubuntu/dists/docker/InRelease 403 Forbidden [IP: 52.85.58.66 443]
E: The repository 'http://get.docker.io/ubuntu docker InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

访问Err：8 https://get.docker.com/ubuntu/中的链接将输出以下内容：

echo "# WARNING! This script is deprecated. Please use the script"
echo "# at https://get.docker.com/"
exit 1

好的，过时的链接，没有问题，所以我下载了在www.example.com上找到的脚本get.docker.com，并使用bash运行它，结果如下：

# Executing docker install script, commit: 36b78b2
+ sudo -E sh -c apt-get update -qq >/dev/null
E: The repository 'http://ppa.launchpad.net/colingille/freshlight/ubuntu bionic Release' does not have a Release file.
E: Failed to fetch http://get.docker.io/ubuntu/dists/docker/InRelease  403  Forbidden [IP: 52.85.58.48 443]
E: The repository 'http://get.docker.io/ubuntu docker InRelease' is not signed.

有什么我可以试试的吗？