Git源码库多账号配置，本质上还是SSH远程登录多账号配置的扩展。先看一下基础的SSH远程登录多账号配置。
在 ~/.ssh/ 下创建一个名为 config 的文件。里面写上如下配置：
Host testVM
HostName xxx.xxx.xxx.xxx
User username
Port 22
IdentityFile /path/to/my/private/key/testVM.pem
注意所有私钥文件权限要设置为 400，config 文件权限要设置为 600。
chmod 400 /path/to/my/private/key/testVM.pem
chmod 600 ~/.ssh/config
然后就可以用代号运行简化的 SSH 远程登录了，比如 ssh testVM。
在此基础之上，当我们有多个 Git源码库需要同时管理时，还是在 config 文件中增加 Git服务器的访问配置。比如：
# Github
Host github.com
User github_user_name
IdentityFile /path/to/my/private/key/github.pem
# Azure Repos，Azure上托管的私有源码库
Host ssh.dev.azure.com
User git
IdentityFile /path/to/my/private/key/repos.pem
需要注意的是配置Git服务器时，不要写 HostName 项，而是直接把Git服务器域名写在 Host 段，这样才能让ssh 和git客户端正常找到相关服务器的配置，加载到需要的私钥。
之后我们就可以用 ssh -Tv [email protected]来验证授权了。其中 -T 参数表示测试验证，-v 表示以1级详细程度输出调试信息。
返回结果比较长，只节选重要的部分：
OpenSSH_7.5p1, OpenSSL 1.0.2o 27 Mar 2018
debug1: Reading configuration data /home/mobaxterm/.ssh/config
debug1: /home/mobaxterm/.ssh/config line 12: Applying options for github.com
...
debug1: Connecting to github.com [192.30.255.113] port 22.
debug1: Connection established.
...
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /path/to/my/private/key/github.pem
debug1: Authentication succeeded (publickey).
Authenticated to github.com ([192.30.255.113]:22).
debug1: Requesting X11 forwarding with authentication spoofing.
debug1: Requesting authentication agent forwarding.
X11 forwarding request failed on channel 0
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
Hi github_user_name! You've successfully authenticated, but GitHub does not provide shell access.
使用 Azure DevOps Repos 作源码库时，使用 ssh -Tv 来验证更为重要，因为它返回的验证成功信息是在调试中的，不加 -v 时会让人感觉验证失败了。
ssh -T [email protected]
X11 forwarding request failed on channel 0
shell request failed on channel 0
加上 -T 参数再看
ssh -Tv [email protected]
OpenSSH_7.5p1, OpenSSL 1.0.2o 27 Mar 2018
debug1: Reading configuration data /home/mobaxterm/.ssh/config
debug1: /home/mobaxterm/.ssh/config line 4: Applying options for ssh.dev.azure.com
...
debug1: Connecting to ssh.dev.azure.com [20.189.107.3] port 22.
debug1: Connection established.
...
debug1: Authenticating to ssh.dev.azure.com:22 as 'git'
debug1: Host 'ssh.dev.azure.com' is known and matches the RSA host key.
debug1: Found key in /home/mobaxterm/.ssh/known_hosts:3
debug1: Authentications that can continue: password,publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /path/to/my/private/key/repos.pem
debug1: Authentication succeeded (publickey).
Authenticated to ssh.dev.azure.com ([20.189.107.3]:22).
...
X11 forwarding request failed on channel 0
shell request failed on channel 0
就可以看到验证通过的信息了。
到此，Git 配置多账号就完成了。下面就可以 git clone 开始快乐编码了.