key to use when executing shell command?

 

A rather unusual situation perhaps, but I want to specify a private SSH-key to use when executing a shell (git) command from the local computer.

Basically like this: 

git clone git@github.com:TheUser/TheProject.git -key "/home/christoffer/ssh_keys/theuser"

Or even better (in Ruby): 

with_key("/home/christoffer/ssh_keys/theuser") do
  sh("git clone git@github.com:TheUser/TheProject.git")
end

I have seen examples of connecting to a remote server with Net::SSH that uses a specified private key, but this is a local command. Is it possible?

Something like this should work (suggested by orip): 

ssh-agent bash -c 'ssh-add /somewhere/yourkey; git clone git@github.com:user/project.git'

if you prefer subshells, you could try the following (though it is more fragile): 

ssh-agent $(ssh-add /somewhere/yourkey; git clone git@github.com:user/project.git)

Git will invoke SSH which will find its agent by environment variable; this will, in turn, have the key loaded.

Alternatively, setting HOME may also do the trick, provided you are willing to setup a directory that contains only a .ssh directory as HOME ; this may either contain an identity.pub, or a config file setting IdentityFile.

None of these solutions worked for me.

Instead, I elaborate on @Martin v. Löwis 's mention of setting a config file for SSH.

SSH will look for the user's ~/.ssh/config file. I have mine setup as: 

Host gitserv
    Hostname remote.server.com
    IdentityFile ~/.ssh/id_rsa.github
    IdentitiesOnly yes # see NOTES below

And I add a remote git repository: 

git remote add origin git@gitserv:myrepo.git

And then git commands work normally for me. 

git push -v origin master

NOTES

  • The IdentitiesOnly yes is required to prevent the SSH default behavior of sending the identity file matching the default filename for each protocol. If you have a file named ~/.ssh/id_rsa that will get tried BEFORE your ~/.ssh/id_rsa.github without this option.

    • References

  • Best way to use multiple SSH private keys on one client
  • How could I stop ssh offering a wrong key

    • Other people's suggestions about ~/.ssh/config are extra complicated. It can be as simple as: 

    Host github.com
  IdentityFile ~/.ssh/github_rsa
    链接地址: http://www.djcxy.com/p/4314.html

    上一篇: 命令行中的配置文件？

    下一篇: 执行shell命令时使用的键？