This chapter will get you started with Borg development.
Borg is written in Python (with a little bit of Cython and C for the performance critical parts).
… are welcome!
Some guidance for contributors:
- discuss about changes on github issue tracker, IRC or mailing list
- make your PRs on the
masterbranch (see Branching Model for details)
- do clean changesets:
- focus on some topic, resist changing anything else.
- do not do style changes mixed with functional changes.
- try to avoid refactorings mixed with functional changes.
- if you need to fix something after commit/push:
- if there are ongoing reviews: do a fixup commit you can merge into the bad commit later.
- if there are no ongoing reviews or you did not push the bad commit yet: edit the commit to include your fix or merge the fixup commit before pushing.
- have a nice, clear, typo-free commit comment
- if you fixed an issue, refer to it in your commit comment
- follow the style guide (see below)
- if you write new code, please add tests and docs for it
- run the tests, fix anything that comes up
- make a pull request on github
- wait for review by other developers
Borg development happens on the
master branch and uses GitHub pull
requests (if you don’t have GitHub or don’t want to use it you can
send smaller patches via the borgbackup Mailing list to the maintainers).
Stable releases are maintained on maintenance branches named x.y-maint, eg. the maintenance branch of the 1.0.x series is 1.0-maint.
Most PRs should be made against the
master branch. Only if an
issue affects only a particular maintenance branch a PR should be
made against it directly.
While discussing / reviewing a PR it will be decided whether the change should be applied to maintenance branch(es). Each maintenance branch has a corresponding backport/x.y-maint label, which will then be applied.
Changes that are typically considered for backporting:
- Data loss, corruption and inaccessibility fixes
- Security fixes
- Forward-compatibility improvements
- Documentation corrections
From time to time a maintainer will backport the changes for a maintenance branch, typically before a release or if enough changes were collected:
Notify others that you’re doing this to avoid duplicate work.
Branch a backporting branch off the maintenance branch.
Cherry pick and backport the changes from each labelled PR, remove the label for each PR you’ve backported.
Make a PR of the backporting branch against the maintenance branch for backport review. Mention the backported PRs in this PR, eg:
Includes changes from #2055 #2057 #2381
This way GitHub will automatically show in these PRs where they were backported.
Previously (until release 1.0.10) Borg used a “merge upwards” model where most minor changes and fixes where committed to a maintenance branch (eg. 1.0-maint), and the maintenance branch(es) were regularly merged back into the main development branch. This became more and more troublesome due to merges growing more conflict-heavy and error-prone.
Code and issues¶
We generally follow pep8, with 120 columns
instead of 79. We do not use form-feed (
^L) characters to
separate sections either. Compliance is tested automatically when
you run the tests.
Output and Logging¶
When writing logger calls, always use correct log level (debug only for debugging, info for informative messages, warning for warnings, error for errors, critical for critical errors/states).
When directly talking to the user (e.g. Y/N questions), do not use logging, but directly output to stderr (not: stdout, it could be connected to a pipe).
To control the amount and kinds of messages output to stderr or emitted at
info level, use flags like
Building a development environment¶
First, just install borg into a virtual env as described before.
To install some additional packages needed for running the tests, activate your virtual env and run:
pip install -r requirements.d/development.txt
Running the tests¶
The tests are in the borg/testsuite package.
To run all the tests, you need to have fakeroot installed. If you do not have fakeroot, you still will be able to run most tests, just leave away the fakeroot -u from the given command lines.
To run the test suite use the following command:
fakeroot -u tox # run all tests
Some more advanced examples:
# verify a changed tox.ini (run this after any change to tox.ini): fakeroot -u tox --recreate fakeroot -u tox -e py34 # run all tests, but only on python 3.4 fakeroot -u tox borg.testsuite.locking # only run 1 test module fakeroot -u tox borg.testsuite.locking -- -k '"not Timer"' # exclude some tests fakeroot -u tox borg.testsuite -- -v # verbose py.test
- When using
--to give options to py.test, you MUST also give
Regenerate usage files¶
Usage documentation is currently committed directly to git, although those files are generated automatically from the source tree.
When a command is added, a commandline flag changed, added or removed, the usage docs need to be rebuilt as well:
However, we prefer to do this as part of our releasing preparations, so it is generally not necessary to update these when submitting patches that change something about the command line.
Building the docs with Sphinx¶
The documentation (in reStructuredText format, .rst) is in docs/.
To build the html version of it, you need to have sphinx installed:
pip3 install sphinx sphinx_rtd_theme # important: this will install sphinx with Python 3
cd docs/ make html
Then point a web browser at docs/_build/html/index.html.
The website is updated automatically through Github web hooks on the main repository.
We use Vagrant for the automated creation of testing environments and borgbackup standalone binaries for various platforms.
For better security, there is no automatic sync in the VM to host direction. The plugin vagrant-scp is useful to copy stuff from the VMs to the host.
# To create and provision the VM: vagrant up OS # To create an ssh session to the VM: vagrant ssh OS command # To shut down the VM: vagrant halt OS # To shut down and destroy the VM: vagrant destroy OS # To copy files from the VM (in this case, the generated binary): vagrant scp OS:/vagrant/borg/borg.exe .
Creating standalone binaries¶
Make sure you have everything built and installed (including llfuse and fuse). When using the Vagrant VMs, pyinstaller will already be installed.
With virtual env activated:
pip install pyinstaller # or git checkout master pyinstaller -F -n borg-PLATFORM borg/__main__.py for file in dist/borg-*; do gpg --armor --detach-sign $file; done
If you encounter issues, see also our Vagrantfile for details.
Standalone binaries built with pyinstaller are supposed to work on same OS, same architecture (x86 32bit, amd64 64bit) without external dependencies.
Creating a new release¶
make sure all issues for this milestone are closed or moved to the next milestone
check if there are any pending fixes for security issues
find and fix any low hanging fruit left on the issue tracker
check that Travis CI is happy
CHANGES.rst, based on
git log $PREVIOUS_RELEASE..
check version number of upcoming release in
python setup.py build_usageand commit
tag the release:
git tag -s -m "tagged/signed release X.Y.Z" X.Y.Z
create a clean repo and use it for the following steps:
git clone borg borg-clean
This makes sure no uncommitted files get into the release archive. It also will find if you forgot to commit something that is needed. It also makes sure the vagrant machines only get committed files and do a fresh start based on that.
run tox and/or binary builds on all supported platforms via vagrant, check for test failures
create a release on PyPi:
python setup.py register sdist upload --identity="Thomas Waldmann" --sign
close release milestone on Github
- Mailing list
- IRC channel (change
- create a Github release, include:
- standalone binaries (see above for how to create them)
- for OS X, document the OS X Fuse version in the README of the binaries. OS X FUSE uses a kernel extension that needs to be compatible with the code contained in the binary.
- a link to
- standalone binaries (see above for how to create them)