背景

给一台阿里云的云服务器安装gitlab-runner的时候遇到了个404的错误，使用的安装命令为curl -L https://packages.gitlab.com/install/repositories/runner/gitlab-ci-multi-runner/script.rpm.sh | sudo bash,错误提示为

curl: (22) The requested URL returned error: 404 Not Found

Unable to download repo config from: https://packages.gitlab.com/install/repositories/runner/gitlab-ci-multi-runner/config_file.repo?os=alinux&dist=2&source=script

This usually happens if your operating system is not supported by
packagecloud.io, or this script's OS detection failed.

You can override the OS detection by setting os= and dist= prior to running this script.
You can find a list of supported OSes and distributions on our website: https://packages.gitlab.com/docs#os_distro_version

问题分析

可以看到，错误提示是不支持当前的系统，因为服务器安装的为阿里云专属镜像AliyunOS，故安装脚本识别的时候会将变量设置为os=alinux，但脚本里没有处理该os，故只能走unknown_os的方法，感兴趣的可以点击这里直接查看安装脚本的源码。

解决方法

因为服务器安装的是Alibaba Cloud Linux 2.1903 LTS 64位，其内核是基于CentOS7的，所以我们手动指定即可，命令如下

wget  https://packages.gitlab.com/install/repositories/runner/gitlab-ci-multi-runner/script.rpm.sh

sudo  os=el dist=7 bash ./script.rpm.sh