步骤：

ssh-keygen -t rsa -C "xxx@xxx.com" -f "~/.ssh/github_rsa"

ssh-add ~/.ssh/github_rsa

touch config - 见config content

ssh -T git@github.com

config content

# github

Host github.com

HostName github.com

PreferredAuthentications publickey

IdentityFile ~/.ssh/github_id_rsa

# gerrit

Host gerrit.qisi.ltd

HostName gerrit.qisi.ltd

User ****

IdentityFile ~/.ssh/id_rsa

Port ****