How to find source branch name of a PR in bitbucket pipeline

[Prashantanu Singh Rathore (Temp)]

I am running bitbucket pipeline where I need to run a script from master. I have to fetch few details from the PR source branch. Hence I need the name for source branch on which we create the pull request. Bitbucket provides the default parameter for the destination but not for the source branch. 

Please help if someone knows the way to find source branch name. Thanks

[Samuel.Sidor]

I achieved this like:

CURRENT_COMMIT_HASH="$(git rev-parse --short HEAD)"

if ! git show ${CURRENT_COMMIT_HASH} | grep -q "Merged in"; then
    echo "Single commit directly added to branch, versioning only works for branch merge."
    return 0
fi

BITBUCKET_PR_SOURCE_BRANCH=$(git show ${CURRENT_COMMIT_HASH} | grep -oP 'Merged in \K.*(?= \(pull request)')
echo "BITBUCKET_PR_SOURCE_BRANCH: ${BITBUCKET_PR_SOURCE_BRANCH}"

IFS='/' read -ra BRANCH_PARTS <<< "${BITBUCKET_PR_SOURCE_BRANCH}" # split branch name by '/'
if [ "${#BRANCH_PARTS[@]}" -eq 0 ]; then
  echo "No branch prefix specified, this commit wont be versioned."
  return 0
fi

[Marco Pellicciotta]

I achieved like this:

COMMIT_INFO=$(git show -s --format=%s $BITBUCKET_COMMIT)
echo $COMMIT_INFO
if [[ $COMMIT_INFO == *"pull request"* ]]; then
    [[ $COMMIT_INFO =~ Merged[[:space:]]in[[:space:]](.+)[[:space:]]\(pull[[:space:]]request ]]
    echo "My source branch is: ${BASH_REMATCH[1]}"
fi

[Theodora Boudale]

Hi @Prashantanu Singh Rathore (Temp)  and welcome to the community!

I assume that this is for a Pipelines build that is running when a pull request is created?

If so, you can get the source branch of the PR with the variable BITBUCKET_BRANCH.

This is a default variable, like BITBUCKET_PR_DESTINATION_BRANCH.

Please feel free to let me know if this works for you and if you need anything further.

Kind regards,
Theodora

[Prashantanu Singh Rathore (Temp)]

Hi Theodora, Thanks for your reply. 

I am merging from 'feature/ABCD' to 'master' branch. 

This merge will initiate the pipeline automatically on master branch. 

I want to know the source branch of PR(feature/ABCD) using any command or variable after the merge. 

So  in my case , $BITBUCKET_BRANCH will give me result as 'master' because I am running master configuration. 

[Theodora Boudale]

Hi @Prashantanu Singh Rathore (Temp) ,

Thank you for the reply and info.

This information is available via default variables only for builds that run on pull requests.

If you have a pipeline that runs on master, there is no PR info available for such builds.

You may be able to retrieve this info with Git commands, however please keep in mind that this will essentially be guesswork, as Git itself doesn't store any PR info.

First, you'll need to execute this command:

git fetch origin "+refs/heads/*:refs/remotes/origin/*"

Then, the following command will give you the two parents of the merge commit:

git show --format="%P" $BITBUCKET_COMMIT

Then, you can execute the following command on the second commit hash (which is the parent commit from the source branch) returned by the previous command:

git branch -a --contains commit_hash

All this assumes that you have merged the PR with merge commit as strategy.

The output of the above command will show you all branches that contain that parent commit, including the source branch (if it still exists and hasn't been deleted).

You can also filter out master by

git branch -a --contains commit_hash | grep -v master

Keep in mind though that if there are more than one branches that contain this commit (and not only the source branch of the PR), they will all be returned by this command.

Kind regards,
Theodora

[Goutham Siddhaarth]

Hi Atlassian Team,

I'm trying to achieve the same, is there any new update on getting the merged feature branch name in the master branch pipeline.

Rgds,
Goutham