How to retrieve the git branch name that was built by Jenkins when using inverse branch selection strategy?

Question

We have one Jenkins job which builds every branch except master when there are new commits. This behavior can be configured via git plugin's 'choosing strategy:inverse' so that it listens to every branch except a specified branch.

This functions very nicely. But the problem is that GIT_BRANCH environment variable always refers to the excluded branch('origin/master' in our case). How to query the actual branch that was built by Jenkins?

Currently I am using a workaround that I grep it from generated changelog.xml. But it happens sometimes that changelog.xml is empty when Jenkins switches between different branches and I cannot find this info. What is the correct way of retrieving/querying from Jenkins the branch that was actually built?

score 18 · Answer 1 · answered Jan 08 '14 at 12:38

18

I successfully used this syntax:

GIT_BRANCH=`git rev-parse HEAD | git branch -a --contains | grep remotes | sed s/.*remotes.origin.//`

answered Jan 08 '14 at 12:38

Piotr Kuczynski

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Great! For anyone else, I had to slightly adjust this to: `git rev-parse HEAD | git branch -a --contains | grep remotes | sed -e 's/.*remotes.origin.//'` for OS X – Jonathan Crooke Jan 22 '14 at 14:41
With master checked out in a repo I'm currently working with, this results in `HEAD -> origin/master\nmaster` (the `\n` is really a newline in the result), which is clearly wrong. – Matt Kantor Apr 09 '14 at 18:18
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Note that --contains will also include branches that are newer than the currently checked out code. This worked better for me: `git show-ref | grep $(git rev-parse HEAD) | grep remotes | grep -v HEAD | sed -e 's/.*remotes.origin.//'` And possibly pipe this to `head -n1` if you want it to arbitrarily pick the first branch name if there are multiple branches pointing to this commit. – Alex Varju Aug 26 '14 at 00:25
Where can I use this in Jenkins? I can't seem to use it as an ant property.. where did you configure this to use it? – Rein Baarsma Feb 15 '17 at 07:11

score 2 · Answer 2 · edited May 23 '17 at 12:00

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Looks like it's a Jenkins bug? You can grab in your build script the name of the checked out branch with this:

git symbolic-ref -q --short HEAD

Actually Jenkins has the working copy in detached HEAD, which is why git branch returns "no branch". See this quite detailed answer for digging into reconciliation with between a detached HEAD and a branch.

edited May 23 '17 at 12:00

Community

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answered Feb 20 '13 at 17:06

CharlesB

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Thanks Charles. That works in a normal git workarea but not in a jenkins workspace where command returns nothing. Running 'git branch' in jenkins workspace gives '*(no branch)'. Probably the chosen branch must be queried from Jenkins in some way as it seems to make the checkout based on commit-id in the chosen branch. – harish Feb 22 '13 at 08:10
Yes, Jenkins works in detached HEAD. see my edit and the linked answer. I'm sure one of the commands linked in it should work. – CharlesB Feb 22 '13 at 08:55
This command works in CMD, but not in my Jenkins, why? C:\Tools\Jenkins\jobs\DevOps\jobs\Test-GitHub\workspace>git --version git version 2.7.0.windows.1 C:\Tools\Jenkins\jobs\DevOps\jobs\Test-GitHub\workspace>git symbolic-ref -q --short HEAD C:\Tools\Jenkins\jobs\DevOps\jobs\Test-GitHub\workspace>exit 1 Build step 'Execute Windows batch command' marked build as failure Finished: FAILURE – Jirong Hu Mar 03 '16 at 16:16

score 2 · Accepted Answer · answered Nov 04 '13 at 02:03

Because git never checks out a branch just a commit directly you have to do the following:

To get the sha of the checked out commit:

git rev-parse HEAD

To get the all branches that commit is under:

git branch -a --contains SHA

The out put of the second command could look like this

master
remotes/origin/HEAD -> origin/master
remotes/origin/develop

score 0 · Answer 4 · answered Dec 02 '15 at 20:59

I can't believe how hard this is. I'm doing this for Jenkins as well. I piggypacked off Piotr Kuczynski's solution:

branch=`git rev-parse HEAD | git branch -a --contains | grep remotes | sed s/.*remotes.origin.//`
branch=`echo $branch | awk '{print $NF}'`

Because sometimes, as Matt Kantor pointed out, Piotr's solution gives a lot of junk back. But the last word in that junk appears to always be correct. Note that this solution only works if the ref you're using corresponds exactly with a branch that exists on remote (so local branches will not work).

How to retrieve the git branch name that was built by Jenkins when using inverse branch selection strategy?

4 Answers4