Git over ssh tunnel

This is a short recipe on how to access a git repository through a shh tunnel.

In this scenario, we have ssh access to remoteserver.corporation1.com.

We want to access a on gitserver.corporation2.com from remoteserver.corporation1.com, the two machines cannot connect to eachother directly in any way.

Solution

Since we can connect to both remoteserver.corporation1.com and gitserver.corporation2.com from our desktop machine, we will establish a ssh tunnel from remoteserver.corporation1.com to gitserver.corporation2.com over our desktop machine.

Start a ssh tunnel session on desktop machine

Option 1 - ssh command

ssh -R 9000:gitserver.corporation2.com:22 remoteserver.corporation1.com

Here we are saying “Remote server remoteserver.corporation1.com should listen on localhost:9000 and forward all traffic to gitserver.corporation2.com:22”.

Option 2 - Putty

This is how we would do the same via Putty

On remote server A

1. Edit ~/.ssh/config

    Host sshtunnel.gitserver.corporation2.com
            HostName localhost
            Port 9000
            User git
            IdentityFile ~/.ssh/git@gitserver.corporation2.com.pem
            IdentitiesOnly yes
   

2. Restart ssh daemon with sudo service ssh restart
3. (optional) If you do not have a git repo yet, init one first with git init <directory>
4. Add a new git remote to git repository git remote add sshtunnelled git@sshtunnel:path/to/your/repository notice how we used the Host specified in the ssh config above
5. .git/config should have a remote similar to this now:

    [remote "sshtunnelled"]
            url = git@sshtunnel.pingec.rds.aioss.com:path/to/your/repository
            fetch = +refs/heads/*:refs/remotes/sshtunnelled/*
   

6. Now you can try using the remote repo, a simple command would be git remote show sshtunnelled
7. If that succeeds you can finally go ahead and do whatever you wanted to do with the now-available repo eg. git pull sshtunnelled master