git-upstream/README.rst

What is git-upstream?

git-upstream is an open source Python application that can be used to keep in sync with upstream open source projects, mainly OpenStack.

The main usecase for this tool is for people who are doing active contributions to repositories that are mirrors of OpenStack repositories, with the intention that most of those contributions will be submitted to review.openstack.org at some point. If you are running a public cloud based on OpenStack, having local changes needed to use it in your environment, you can use git-upstream to stay up to date with the upstream master in a easier way (with respect to using raw git commands).

git-upstream provides new git subcommands to support rebasing of local-carried patches on top of upstream repositories. It provides commands to ease the use of git for who needs to integrate big upstream projects in their environment. The operations are performed using Git commands.

Note

currently git-upstream can be used only for projects that are maintained with Gerrit as it relies on the presence of Change-IDs. Nevertheless, the code is quite modular and can be extended to use any part of commit message (e.g., other headers).

Current git-upstream version supports the following features

• Single upstream branch import

Your repository is tracking an upstream project and has local changes applied and no other branch is merged in. This can also be applied to tracking upstream packaging branches: e.g., ubuntu/master => ubuntu/saucy-proposed/nova + local packaging changes.

• Multi branch import (upstream branch + additional branches)

In this case, your project tracks an upstream repository, merges in an arbitrary number of branches and applies local carried changes.

• Re-reviewing

Reviewing (w/ Gerrit) of all locally applied changes if desired. git-upstream creates an import branch in a manner that allows it to be fully re-reviewed or merged into master and pushed.

• Detailed logging

git-upstream can output to both console and log file simultaneously. Multiple levels and these are managed separately for log file and console output. This means jobs run by Jenkins can save a detailed log file separately as an artefact while printing status information to the console if those running the jobs don’t wish to have the console spammed with the details.

• Dropping of changes that appear upstream

Compares Change-Id's of changes applied since previous import with those that have appeared on the upstream branch since the last import point.

• Interactive mode

Once the list of changes to be re-applied has been determined (and those to be dropped have been pruned), the tool can open an editor (controlled by your git editor settings) for users to review those changes to be made and allow them to perform further operations such as re-ordering, dropping of obsolete changes, squashing.

• Dropping local changes

It’s always possible for local changes to be superseded by upstream changes, so when these are identified and marked as such, we should drop them.

This can also occur where a change was applied locally, modified when being upstreamed based on review feedback and the resulting differences were ported to the internal as well. While the original change will be automatically dropped, also useful to drop the additional ported changes automatically if possible, rather than have it cause conflicts.

What git-upstream is not

The name of this tool includes the "git-" prefix because of the Git naming convention that a Git subcommand must have. So, as git-review (usually invoked with "git review [...]"), this tool can be invoked using "git upstream [...]".

That said, and even if git-upstream currently uses Change-Ids, it is not strictly related to git-review. In other words, git-review can (and most of the time will) be used without even knowing about git-upstream existence.

git-upstream installation

At the time of writing, there are two ways to install git-upstream: cloning its git repository or using pip.

Installing from git repository

git clone https://git.openstack.org/openstack/git-upstream.git
cd git-upstream
# Install git-upstream itself
python setup.py install

Installing from PyPI

pip install git-upstream

See also https://pypi.python.org/pypi/git-upstream

Using git-upstream

Please see workflows

Available commands

Please see subcommands

Authors

git-upstream was written by Darragh Bailey dbailey@hpe.com.

Acknowledgements

Thanks to Aleksander Korzynski and Stanisław Pitucha for taking the original design spec and some basic manual steps and experimenting with initial implementations.

To Davide Guerri, for picking up a rough python tool and turning it into something that was actually usable.

Also to Jon Paul Sullivan and Monty Taylor to listening and providing a sounding board for different approaches.

And finally to Coleman Corrigan among numerous others who acted as willing guinea pigs for the original manual approach.

Hope this eventually helped save you time and some hair.