With svn, you can tag a remote repository with:

svn cp http://{your-svn-server}/svn/{project}/trunk http://{your-svn-server}/svn/{project}/tags/{tag-name}

or if you're already in a working copy:

svn cp ^/{project}/trunk ^/{project}/tags/{tag-name}

The latter case assumes you have a working copy already checked out, but the first case is more interesting for what I needed.

Tagging when deploying

Lately I've been working on some deployment tools in the form of a few fabric classes. One of the things I want to do when launching a production deployment is auto-tagging the repository with the new build name.

The tag naming I went for is something like:

<project_name> - <date> - <time> - <who_deployed>

Example:

geodns-20110409-133701-cosimo

Every time there's a new production deployment using these tools, the
repository / revision that is being deployed is tagged with names like those.
The plan to use this added metadata for a "deployment console", but I didn't
have time to do anything about it yet.

vcs.py

Having planned the move from svn to git, I had to add a thin abstraction to the
fabric deployment classes to make sure that when the repository url changed from
svn to git, nothing really changed from the deployment point of view.

I ended up with a generic vcs.py class for fabric that implements vcs-related actions such as:

• exporting a remote repository to a local directory
• listing available tags on a remote repository
• tagging a remote repository

This means I had to find out how to do these things in both svn and git.

Exporting a remote repository

With svn:

svn export [--force] http://svn.server/project/trunk /your/local/dir

and you can use --force if the local directory already exists, or svn will refuse to do it by default.

Git requires an intermediate step:

git archive --prefix=some-dir-name/ --remote=git.server:/var/git/project.git master | tar xvC /path/where/to/export

Listing available tags (remotely)

With svn:

svn list http://svn.server/project/tags/

With git:

git ls-remote --tags git.server:/var/git/project.git

Thanks to my colleague Alfie for the ls-remote tip.

Tagging a remote URL

I mentioned how you do it with svn:

svn cp http://svn.server/project/trunk http://svn.server/project/tags/tagname

What about git though? I searched a bit around, and I found no git command to
directly tag a remote repository.

I looked at the Jenkins git plugin source code but AFAICS there's no magical way to do it, so I figured out I would just clone the remote repository, tag locally and then push the tag to origin.

In theory, this should be just fine, except it has some drawbacks:

• Execution time: if the remote repository is very large, we need to clone it first, and that can take a long time.
• Size: when cloning a large git repository, the local copy will take up disk space for nothing. We don't need it, as we just want to tag the remote repository.

Not sure this is the best thing to do, but what I'm using right now is:

• Cloning with --depth=1:

  git clone has a --depth option that limits the amount of history that is cloned. In this case, we don't need any history, so --depth=1 is great:

  git clone --depth=1 <git-remote-url> <local-dir>

  Example:

  git clone --depth=1 git.server:/var/git/project.git /var/tmp/deploy.$USER.$$

• Tagging locally:

  cd /var/tmp/deploy.$USER.$$
  git tag -as <tag-name>
  

• Pushing the tag remotely:

  git push origin --tags

• Removing the temporary local copy:

  rm -rf /var/tmp/deploy.$USER.$$

That's it. Not very brilliant, but works great for now. If you know of a better way to tag a remote git repository, or some existing work on these things, please get in touch or add a comment below. Thanks! :)