Maintaining Customizations

Some customizations to Phabricator can't be accomplished by extensions but require modifying the Phabricator source code.

This can be maintained in a number of different ways. Here is the process I'm currently using. Note that it has a few rough edges.

General Process

1. Set up and host a forked version of arcanist and phabricator repositories. This will be the origin remote location which the Phabricator server clones/pulls from.
2. Create a separate branch which will contain the customizations, e.g. custom. Note that even if customizations only exist in one repo this branch needs to exist in both repos, as the service script assumes to setup both repositories to the same named branch.
3. Update Phabricator by pulling updates from public/upstream, merge custom onto latest stable, push to the forked repo.

Phabricator Server Setup

The phabricator server needs to be configured to pull from the forked repository as well as use the custom branch. For both phabricator and arcanist repositories on the Phabricator server do the following.

If hosting these repositories in a forge that requires credentials to access, configure git to use and store these credentials on the Phabricator server. In this example phabricator and arcanist do not share credentials.

# setup credentials, use separate files for phabricator vs. arcanist since git by default stores credentials per-server
$ cd /usr/local/phacility/phabricator
$ git config credential.helper 'store --file=/usr/local/phacility/.git-credentials-phabricator'
$ git fetch --all
# use the project credentials when prompted, this will store for future use

$ cd /usr/local/phacility/arcanist
$ git config credential.helper 'store --file=/usr/local/phacility/.git-credentials-arcanist'
$ git fetch --all
# use the project credentials when prompted, this will store for future use

Then update the service script to set the default branch, BRANCH=custom.

Local Repository Setup

To update Phabricator a copy of the forked repository will need to be cloned locally, origin. Additionally on this local repository a new remote location will need to be setup pointing to the public Phabricator repositories, upstream.

Do this for both phabricator and arcanist repositories:

$ git clone ssh://git@my-hosted-server.com:phacility/phabricator.git
$ cd phabricator
# setup to only fast-forward merge
$ git config merge.ff only

# checkout the stable, master, and custom branches
$ git checkout --track -b origin-stable origin/stable
$ git checkout --track -b origin-master origin/master
$ git checkout --track -b custom origin/custom

# add upstream remote
$ git remote add upstream git@github.com:phacility/phabricator.git
$ git checkout --track -b upstream-stable upstream/stable
$ git checkout --track -b upstream-master upstream/master

Updating

When ready to pull in the latest updates from Phabricator, pull in the public changes from upstream, update the upstream-master and upstream-stable branches to match, merge the origin-master and origin-stable branches to the upstream versions, then merge custom on top of origin-stable (or origin-master).

# pull updates from both origin and upstream, update the local branches to their updated states
# do this for both arcanist and phabricator, for both stable and master branch variants
$ git fetch --all
$ git checkout upstream-stable
$ git pull                       # ff-only pull to update upstream-stable to (remote) upstream/stable
$ git checkout origin-stable
$ git merge upstream-stable      # merge the origin-stable to match upstream-stable
$ git push origin origin-stable  # push the updated stable branch to origin

# merge custom branch onto new stable
$ git checkout custom
$ git merge origin-stable
# address conflicts, if any

# push the custom branch
$ git push origin custom