Tag: git

The Case of the Mysterious Git Repo

I’m migrating scripts from one CentOS host to another. (The old one is CentOS 6 and the new one is CentOS 7.) One of the items I want to move is a script that’s part of a git repo.

I know it’s a git repo because it has a .git directory. The directory and files are owned by a local user, luser1.

Where did this git repo come from?

You can call git config -l and it will tell you things about the repo, including the remote.origin.url. Now I can tell that it came from my GitHub Enterprise (GHE) instance.

But it doesn’t tell you who created it. And luser1 doesn’t exist on my GitHub Enterprise instance.

I tried to clone it on the new host, just to see what would happen:

$ sudo -u luser1 git clone git@github.osric.net:team1/the-sauce.git

Result:

fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Somehow luser1 is able to interact with this repo on the old host, even though the user doesn’t exist in GHE.

Fortunately the local repo has some history:

$ head -n1 .git/logs/HEAD

Result:

0000000000000000000000000000000000000000 ab509345a16d987dac10987c4bc2df0c0dfb3ed9 luser1 luser1 <luser1@oldhost.osric.net> 1505633110 -0500   clone: from git@github.osric.net:team1/the-sauce.git

Right there there it is, all the info I wanted! Except that’s the same user, the user that doesn’t even exist in GitHub Enterprise.

Or does it? I went looking at some of the other users in my GitHub Enterprise instance. There were a few system accounts, and when I checked some of them had several SSH keys associated with the accounts. One of the SSH key fingerprints even said luser1.

I wanted to compare that key fingerprint to the key in /home/luser1/.ssh/id_rsa.pub. I can never remember how to do that, but StackOverflow had the answer on How do I find my RSA key fingerprint?

$ ssh-keygen -lf /home/luser1/.ssh/id_rsa.pub

Result:

2048 bb:fc:1c:03:17:5f:67:4f:1f:0b:50:5a:9f:f9:30:e5 /home/luser1/.ssh/id_rsa.pub (RSA)

The fingerprint matches! The SSH key was added to a completely different username in GitHub Enterprise which does have access to the repo.

That works, but why would someone do that? Convenience, I assume, but it wasn’t obvious when I needed to reverse-engineer it!

Converting a CVS project to a Git repository

Why do I still have projects in CVS in 2018?

  1. I inherited them
  2. Inertia

Fortunately, the cvs2svn project includes cvs2git. The instructions included are good, but here are a few things I ran into that may be useful:

You need the actual CVS repo, not a checked out copy. If you run cvs2git on a checked-out copy, you will get an error message like:

ERROR: No RCS files found under 'projectname'

I found that mentioned on svn2git fails “ERROR: No RCS files found under…”. A comment there mentions getting a tarball of your project from Sourceforge, but if you aren’t working with a Sourceforge project, make your own tarball:

tar -cf cvs.tar.gz /path/to/CVS

I created a tarball because I am not running cvs2git on the same machine as my actual CVS repo. cvs2git is non-destructive, and I have backups in case something goes wrong, but I didn’t feel like taking any risks (or testing my restore procedures) at that moment.

I ended up running cvs2git on a Fedora VM. First, install CVS:

sudo dnf install cvs

Install cvs2svn:

wget http://cvs2svn.tigris.org/files/documents/1462/49543/cvs2svn-2.5.0.tar.gz
tar -xf cvs2svn-2.5.0.tar.gz
cd cvs2svn-2.5.0
make install

Create the blob and dump files (you’ll import these into git shortly):

cvs2git --blobfile=/tmp/gitblob.dat --dumpfile=/tmp/gitdump.dat /path/to/specific/cvs/project

Create a bare git repository:

git init --bare reponame
cd reponame

Import the blob and dump files into the git repository:

cat /tmp/gitblob.dat /tmp/gitdump.dat | git fast-import

Now the CVS project is a git repository! Great, but how do I put a bare repo on GitHub or a GitHub Enterprise instance? The article Moving a repository from GitHub.com to GitHub Enterprise was helpful:

git remote add origin git@[hostname]:[owner]/[repo-name].git
git push origin--mirror

(It’s still a bare repo locally, so if you want to check it out you can clone it out to another destination folder, or rm -rf the local repo and clone it.)

The last thing I wanted to do: make the current CVS project read-only. That turned out to be more confusing than I expected, so I’ve turned that into a separate post, Make a CVS project read-only.