Xcode Push to Multiple Git Remotes?
After the recent GitLab meltdown, Peter Molnar wondered if there were ways to push to multiple repositories simultaneously and proposes a couple of ideas.
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The recent meltdown of GitLab made me more aware again about the remote repository and thinking about using more than one provider in git, with only one push. In a pure git based situation it is quite easy, actually, you can use hacks and official solutions. Let see quickly what are they:
At the beginning, there was a small hack to modify the git config of your local working copy. The file is located under the root directory of your local repository, in the .git folder, called config. If you open the file (for example from the terminal with nano or vi) you will see a quite straightforward configuration, with sections like the following originally created config:
[remote "origin"] url = email@example.com:petermolnar_hu/testformuliple.git fetch = +refs/heads/*:refs/remotes/origin/* [branch "master"] remote = origin merge = refs/heads/master
And here comes the hack:
[remote "origin"] url = firstname.lastname@example.org:petermolnar_hu/testformuliple.git url = email@example.com:petermolnar-hu/TestForMultiple.git fetch = +refs/heads/*:refs/remotes/origin/* [branch "master"] remote = origin merge = refs/heads/master
The hack was quite easy here, you have just added another URL line to the remote, with the proper URL to your repository, and that’s it. It is still a hack since git doesn’t support multiple pulls like this! It works like a charm (until you have different states on the remote repositories and you try just pull) from the terminal.
Hack #2 – Solution #1
Nowadays we have a command and respective configuration entries to add a push URL to our remote. I marked it as not just a hack, but an actual solution since it is supported by git. The only caveat is that when you are adding push URLs, you need to add the original URL again, otherwise, git won’t push to the original remote – what a surprise. It works pretty well from the command line.
As an example I can add more push URLs with the commands below:
$git remote add backup firstname.lastname@example.org:petermolnar_hu/testformuliple
We need to re-add the original URL:
$git remote set-url --add --push backup email@example.com:petermolnar_hu/testformuliple
Now we can add extra URLs to push:
$git remote set-url --add --push backup firstname.lastname@example.org:petermolnar_hu/TestForMultiple.git
In this case, your config file will look like this:
[remote "origin"] url = email@example.com:petermolnar_hu/testformuliple.git pushurl = firstname.lastname@example.org:petermolnar-hu/TestForMultiple.git pushurl = email@example.com:petermolnar_hu/testformuliple.git fetch = +refs/heads/*:refs/remotes/origin/* [branch "master"] remote = origin merge = refs/heads/master
The third one is a real hack. You have probably heard about the git-hooks. In a nutshell, git hooks give you an opportunity to run a shell script when you invoke certain git commands. Some of the hooks are pre- or post- hooks, which means that they will run before or after the command.
And the last classification is based on which side the hooks have invoked: on the local or the remote repository (on your machine or on the git server).
For example, pre-commit hook is a local hook, and it is invoked by the
git commit command.
pre-receive is a remote hook, invoked by git-receive-pack. You can find out what types of hooks supported on your system by using the
git hooks —help command. The executable hook scripts live in your repositories
So, the hack is to start git push to different remote(s) from one of the hooks. It is a bit risky, though, since every time you start the git command, the system will push to the remotes, whether you want to push or not. I created a backup remote:
git remote add backup firstname.lastname@example.org:petermolnar-hu/TestForMultiple.git
And then the hack goes into the local post-commit hook:
#!/bin/sh export GIT_SSH_COMMAND="ssh -i /Users/user/.ssh/mySecretKey" git push backup
As you can see, there is also a hack in the hack, I explicitly defined the key file I wanted to use in the
What About Xcode?
Believe me, I had spent almost two weeks trying to figure out if one of the hacks above could work with Xcode from the GUI. Alas, without any success. For me it seems Xcode is using a perl script as an intermediary between the GUI and the commands, but I couldn’t manage to break it.
It is quite frustrating, but at the time of writing the only way to push to multiple remotes with one command is only available from the terminal.
PS: If you figured out the ultimate trick, please share with us!
Published at DZone with permission of Peter Molnar. See the original article here.
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