githookmirroringgit-pushgitorious

How to specify which SSH key to use within git for git push in order to have gitorious as a mirror?


I have a project hosted on git.debian.org (alioth) and I'd like to configure a post-receive hook to update a mirror of the repository on http://gitorious.org

I suppose I'll have to use git push --mirror gitorious

Now, I'll need to have Alioth authorized on gitorious for the push to succeed. How do I do that?

I suppose I need to configure a user on gitorious and create a ssh key for it. And then when I do the git push in the post-receive hook, make sure this ssh key is used.

I could use a ~/.ssh/config but the problem is that many users can push on alioth, and everyone would have to log in and configure the ~/.ssh/config. Instead, I'd like to have a command line option or an environment variable to tell ssh which key to use. Can I do that?

Also, do you have other ideas how mirroring can be achieved? And, is it possible to configure it the other way around (gitorious pushing on alioth)?


Solution

  • The answer is to be found in the git reference manual.

    GIT_SSH

    If this environment variable is set then git fetch and git push will use this command instead of ssh when they need to connect to a remote system. The $GIT_SSH command will be given exactly two arguments: the username@host (or just host) from the URL and the shell command to execute on that remote system.

    To pass options to the program that you want to list in GIT_SSH you will need to wrap the program and options into a shell script, then set GIT_SSH to refer to the shell script.

    Usually it is easier to configure any desired options through your personal .ssh/config file. Please consult your ssh documentation for further details.

    So, I need to write a wrapper script, I write this push-gitorious.sh script:

    #!/bin/sh
    
    
    if [ "run" != "$1" ]; then
      exec ssh -i "$GITORIOUS_IDENTITY_FILE" -o "StrictHostKeyChecking no" "$@"
    fi
    
    remote=YOUR_SSH_GITORIOUS_URL
    
    echo "Mirroring to $remote"
    
    export GITORIOUS_IDENTITY_FILE="`mktemp /tmp/tmp.XXXXXXXXXX`"
    export GIT_SSH="$0"
    
    cat >"$GITORIOUS_IDENTITY_FILE" <<EOF
    YOUR SSH PRIVATE KEY
    
    EOF
    cat >"$GITORIOUS_IDENTITY_FILE.pub" <<EOF
    YOUR SSH PUBLIC KEY
    
    EOF
    
    #echo git push --mirror "$remote"
    git push --mirror "$remote"
    
    rm -f "$GITORIOUS_IDENTITY_FILE"
    rm -f "$GITORIOUS_IDENTITY_FILE.pub"
    
    exit 0
    

    Of course, you have to fill in the private key (the public key is included in the script for reference only. You also need to fill in the gitorious URL.

    In the post-receive hook, you have to put:

    path/to/push-gitorious.sh run
    

    The run option is important, otherwise it will run ssh directly.

    Warning: no checking is done on the remote host identity. You can remove the option from the ssh command line and customize known_hosts if you want to. In this use case, I don't think it's important.