The python script that works with PyGerrit to merge all changes within a given topic/branch. This is a useful tool for merging a set of autorelease changes or version bump patches during for self-managed projects in ODL. 

Ex: This takes input of a Gerrit user (for auth), branch, topic etc.

python merge_changes_in_topic.py -u askb -o jenkins-releng@opendaylight.org -to Phosphorus-SR2 -br stable/phosphorus

This python script automates a part of the release workflow used for merging
patches during the version bumping process for a new release.

The script takes the input file `merge-order.log`. The list of changes are
obtained from a topic and a merge is initiated when the parent project
has been merged successfully, determined while listening on stream-events.

The output is list of changes successfully merged.

The script requires 'pygerrit' module installed within the virtualenv.

usage: merge_changes.py [-h] [-g HOSTNAME] [-p PORT] [-u USERNAME] [-b]
                           [-t SECONDS] [-v] [-i] [-f MERGELOG] [-to TOPIC]
                           [-br BRANCH] [-o OWNER]

Ref: https://review.openstack.org/Documentation/cmd-set-reviewers.html

Steps to test:
virtualenv ~/.virtualenvs/testpy
source ~/.virtualenvs/testpy/bin/activate
pip install --upgrade pygerrit
python merge_changes_in_topic.py -u askb -o jenkins-releng@opendaylight.org -to Oxygen-SR3 -br stable/oxygen
 

Code: https://git.opendaylight.org/gerrit/c/releng/builder/+/103678 

1. Migrate the code to Python3x, it needs to use an updated version of Pygerrit3?.
2. (optional) Integrate this into lftools

Note: This tool is only used for automation, so do not run/test this on any of the production Gerrits.