Not able to detect branch from Git post-receive hook

Question

I've got a post receive hook setup on the remote repo that tries to determine the branch name of the incoming push as follows:

$branch = `git rev-parse --abbrev-ref HEAD`

What i'm finding, though, is that no matter what branch I push from my $branch variable gets set with 'master'.

Any ideas?

Imposture

Answer 1

The post-receive hook gets the same data as the pre-receive and not as arguments, but from stdin. The following is sent for all refs:

oldRev (space) newRev (space) refName (Line feed)

You could parse out the ref name with this bash script:

while read oldrev newrev ref
do
    echo "$ref"
done

Bend

except beware if post-receive is receiving a git push --tags for example (and probably git push origin my_tagname) then the ref you'll be getting is refs/tags/my_tagname and not refs/branch/my_branchname – Thelma

How can I switch to the previous commit, in post-receive hook? – Toitoiboid

Answer 2

You could also do something like this using bash variable substitution:

read oldrev newrev ref

branchname=${ref#refs/heads/}

git checkout ${branchname}

Bergin

Perfect, and then combine with @ralphtheninja's loop to read all when multiple branches are pushed – Balanchine

Answer 3

Magnus' solution didnt work for me, but this did:

#!/bin/bash

echo "determining branch"

if ! [ -t 0 ]; then
  read -a ref
fi

IFS='/' read -ra REF <<< "${ref[2]}"
branch="${REF[2]}"

if [ "master" == "$branch" ]; then
  echo 'master was pushed'
fi

if [ "staging" == "$branch" ]; then
  echo 'staging was pushed'
fi

echo "done"

Marlenemarler

That's because you are looking for the word master, but what you received was refs/head/master. Using read you turned the string into an array delimited by '/'. Then you plucked out the value. – Rriocard

Hi Can you help on how to add and condition in if like if ["master" == "$branch" && "development"=="$branch"]. How to use and condition in this if in hook. Advance thanks. – Chemisorb

Answer 4

Both these answers are correct, but I was having trouble getting stdin to the next common function post-receive-email. Here is what I ended up with:

read oldrev newrev ref
echo "$oldrev" "$newrev" "$ref" | . /usr/share/git-core/contrib/hooks/post-receive-email


if [ "refs/heads/qa" == "$ref" ]; then
  # Big Tuna YO!
  wget -q -O - --connect-timeout=2 http://127.0.0.1:3000/hooks/build/qa_now
fi

Protozoology

Answer 5

You need to read the arguments that are being passed to the script. That should have the branch name and new and old revisions and run for each branch pushed

Cottle