Contributions are welcome and are greatly appreciated! Every little bit helps, and credit will always be given.
- TOC
- Types of Contributions
- Documentation
- Development and Testing
- Pull requests guidelines
- Changing the Metadata Database
Report bugs through Apache Jira
Please report relevant information and preferably code that exhibits the problem.
Look through the Jira issues for bugs. Anything is open to whoever wants to implement it.
Look through the Apache Jira for features. Any unassigned "Improvement" issue is open to whoever wants to implement it.
We've created the operators, hooks, macros and executors we needed, but we made sure that this part of Airflow is extensible. New operators, hooks, macros and executors are very welcomed!
Airflow could always use better documentation,
whether as part of the official Airflow docs,
in docstrings, docs/*.rst
or even on the web as blog posts or
articles.
The best way to send feedback is to open an issue on Apache Jira
If you are proposing a feature:
- Explain in detail how it would work.
- Keep the scope as narrow as possible, to make it easier to implement.
- Remember that this is a volunteer-driven project, and that contributions are welcome :)
The latest API documentation is usually available
here. To generate a local version,
you need to have set up an Airflow development environment (see below). Also
install the doc
extra.
pip install -e .[doc]
Generate and serve the documentation by running:
cd docs
./build.sh
./start_doc_server.sh
Only a subset of the API reference documentation builds. Install additional extras to build the full API reference.
There are three ways to setup an Apache Airflow development environment.
- Using tools and libraries installed directly on your system.
Install Python (2.7.x or 3.5.x), MySQL, and libxml by using system-level package managers like yum, apt-get for Linux, or Homebrew for Mac OS at first. Refer to the base CI Dockerfile for a comprehensive list of required packages.
Then install python development requirements. It is usually best to work in a virtualenv:
cd $AIRFLOW_HOME
virtualenv env
source env/bin/activate
pip install -e .[devel]
- Using a Docker container
Go to your Airflow directory and start a new docker container. You can choose between Python 2 or 3, whatever you prefer.
# Start docker in your Airflow directory
docker run -t -i -v `pwd`:/airflow/ -w /airflow/ -e SLUGIFY_USES_TEXT_UNIDECODE=yes python:3 bash
# Install Airflow with all the required dependencies,
# including the devel which will provide the development tools
pip install -e ".[hdfs,hive,druid,devel]"
# Init the database
airflow initdb
nosetests -v tests/hooks/test_druid_hook.py
test_get_first_record (tests.hooks.test_druid_hook.TestDruidDbApiHook) ... ok
test_get_records (tests.hooks.test_druid_hook.TestDruidDbApiHook) ... ok
test_get_uri (tests.hooks.test_druid_hook.TestDruidDbApiHook) ... ok
test_get_conn_url (tests.hooks.test_druid_hook.TestDruidHook) ... ok
test_submit_gone_wrong (tests.hooks.test_druid_hook.TestDruidHook) ... ok
test_submit_ok (tests.hooks.test_druid_hook.TestDruidHook) ... ok
test_submit_timeout (tests.hooks.test_druid_hook.TestDruidHook) ... ok
test_submit_unknown_response (tests.hooks.test_druid_hook.TestDruidHook) ... ok
----------------------------------------------------------------------
Ran 8 tests in 3.036s
OK
The Airflow code is mounted inside of the Docker container, so if you change something using your favorite IDE, you can directly test is in the container.
- Using Docker Compose and Airflow's CI scripts.
Start a docker container through Compose for development to avoid installing the packages directly on your system. The following will give you a shell inside a container, run all required service containers (MySQL, PostgresSQL, krb5 and so on) and install all the dependencies:
docker-compose -f scripts/ci/docker-compose.yml run airflow-testing bash
# From the container
pip install -e .[devel]
# Run all the tests with python and mysql through tox
pip install tox
tox -e py35-backend_mysql
If you wish to run individual tests inside of docker enviroment you can do as follows:
# From the container (with your desired enviroment) with druid hook
tox -e py35-backend_mysql -- tests/hooks/test_druid_hook.py
To run tests locally, once your unit test environment is setup (directly on your
system or through our Docker setup) you should be able to simply run
./run_unit_tests.sh
at will.
For example, in order to just execute the "core" unit tests, run the following:
./run_unit_tests.sh tests.core:CoreTest -s --logging-level=DEBUG
or a single test method:
./run_unit_tests.sh tests.core:CoreTest.test_check_operators -s --logging-level=DEBUG
To run the whole test suite with Docker Compose, do:
# Install Docker Compose first, then this will run the tests
docker-compose -f scripts/ci/docker-compose.yml run airflow-testing /app/scripts/ci/run-ci.sh
Alternatively can also set up Travis CI on your repo to automate this. It is free for open source projects.
Another great way of automating linting and testing is to use Git Hooks. For example you could create a pre-commit
file based on the Travis CI Pipeline so that before each commit a local pipeline will be triggered and if this pipeline fails (returns an exit code other than 0
) the commit does not come through.
This "in theory" has the advantage that you can not commit any code that fails that again reduces the errors in the Travis CI Pipelines.
Since there are a lot of tests the script would last very long so you propably only should test your new feature locally.
The following example of a pre-commit
file allows you..
- to lint your code via flake8
- to test your code via nosetests in a docker container based on python 2
- to test your code via nosetests in a docker container based on python 3
#!/bin/sh
GREEN='\033[0;32m'
NO_COLOR='\033[0m'
setup_python_env() {
local venv_path=${1}
echo -e "${GREEN}Activating python virtual environment ${venv_path}..${NO_COLOR}"
source ${venv_path}
}
run_linting() {
local project_dir=$(git rev-parse --show-toplevel)
echo -e "${GREEN}Running flake8 over directory ${project_dir}..${NO_COLOR}"
flake8 ${project_dir}
}
run_testing_in_docker() {
local feature_path=${1}
local airflow_py2_container=${2}
local airflow_py3_container=${3}
echo -e "${GREEN}Running tests in ${feature_path} in airflow python 2 docker container..${NO_COLOR}"
docker exec -i -w /airflow/ ${airflow_py2_container} nosetests -v ${feature_path}
echo -e "${GREEN}Running tests in ${feature_path} in airflow python 3 docker container..${NO_COLOR}"
docker exec -i -w /airflow/ ${airflow_py3_container} nosetests -v ${feature_path}
}
set -e
# NOTE: Before running this make sure you have set the function arguments correctly.
setup_python_env /Users/feluelle/venv/bin/activate
run_linting
run_testing_in_docker tests/contrib/hooks/test_imap_hook.py dazzling_chatterjee quirky_stallman
For more information on how to run a subset of the tests, take a look at the nosetests docs.
See also the list of test classes and methods in tests/core.py
.
Feel free to customize based on the extras available in setup.py
Before you submit a pull request from your forked repo, check that it meets these guidelines:
- The pull request should include tests, either as doctests, unit tests, or both. The airflow repo uses Travis CI to run the tests and codecov to track coverage. You can set up both for free on your fork (see the "Testing on Travis CI" section below). It will help you making sure you do not break the build with your PR and that you help increase coverage.
- Please rebase your fork, squash commits, and resolve all conflicts.
- Every pull request should have an associated JIRA. The JIRA link should also be contained in the PR description.
- Preface your commit's subject & PR's title with [AIRFLOW-XXX] where XXX is the JIRA number. We compose release notes (i.e. for Airflow releases) from all commit titles in a release. By placing the JIRA number in the commit title and hence in the release notes, Airflow users can look into JIRA and Github PRs for more details about a particular change.
- Add an Apache License header to all new files
- If the pull request adds functionality, the docs should be updated as part of the same PR. Doc string are often sufficient. Make sure to follow the Sphinx compatible standards.
- The pull request should work for Python 2.7 and 3.5. If you need help writing code that works in both Python 2 and 3, see the documentation at the Python-Future project (the future package is an Airflow requirement and should be used where possible).
- As Airflow grows as a project, we try to enforce a more consistent style and try to follow the Python community guidelines. We track this using landscape.io, which you can setup on your fork as well to check before you submit your PR. We currently enforce most PEP8 and a few other linting rules. It is usually a good idea to lint locally as well using flake8 using
flake8 airflow tests
.git diff upstream/master -u -- "*.py" | flake8 --diff
will return any changed files in your branch that require linting. - Please read this excellent article on commit messages and adhere to them. It makes the lives of those who come after you a lot easier.
We currently rely heavily on Travis CI for running the full Airflow test suite as running all of the tests locally requires significant setup. You can setup Travis CI in your fork of Airflow by following the Travis CI Getting Started guide.
There are two different options available for running Travis CI which are setup as separate components on GitHub:
- Travis CI GitHub App (new version)
- Travis CI GitHub Services (legacy version)
-
Once installed, you can configure the Travis CI GitHub App at https://github.com/settings/installations/169040.
-
For the Travis CI GitHub App, you can set repository access to either "all repositories" for convenience, or "only select repositories" and choose
<username>/incubator-airflow
in the dropdown. -
You can access Travis CI for your fork at
https://travis-ci.com/<username>/incubator-airflow
.
The Travis CI GitHub Services versions uses an Authorized OAuth App. Note
that apache/incubator-airflow
is currently still using the legacy version.
-
Once installed, you can configure the Travis CI Authorized OAuth App at https://github.com/settings/connections/applications/88c5b97de2dbfc50f3ac.
-
If you are a GitHub admin, click the "Grant" button next to your organization; otherwise, click the "Request" button.
-
For the Travis CI Authorized OAuth App, you may have to grant access to the forked
<organization>/incubator-airflow
repo even though it is public. -
You can access Travis CI for your fork at
https://travis-ci.org/<organization>/incubator-airflow
.
The travis-ci.org site for open source projects is now legacy and new projects should instead be created on travis-ci.com for both private repos and open source.
Note that there is a second Authorized OAuth App available called "Travis CI for Open Source" used for the legacy travis-ci.org service. It should not be used for new projects.
More information:
- Open Source on travis-ci.com
- Legacy GitHub Services to GitHub Apps Migration Guide
- Migrating Multiple Repositories to GitHub Apps Guide
When developing features the need may arise to persist information to the the metadata database. Airflow has Alembic built-in to handle all schema changes. Alembic must be installed on your development machine before continuing.
# starting at the root of the project
$ pwd
~/airflow
# change to the airflow directory
$ cd airflow
$ alembic revision -m "add new field to db"
Generating
~/airflow/airflow/migrations/versions/12341123_add_new_field_to_db.py
airflow/www_rbac/
contains all npm-managed, front end assets.
Flask-Appbuilder itself comes bundled with jQuery and bootstrap.
While these may be phased out over time, these packages are currently not
managed with npm.
Make sure you are using recent versions of node and npm. No problems have been found with node>=8.11.3 and npm>=6.1.3
First, npm must be available in your environment. If it is not you can run the following commands (taken from this source)
brew install node --without-npm
echo prefix=~/.npm-packages >> ~/.npmrc
curl -L https://www.npmjs.com/install.sh | sh
The final step is to add ~/.npm-packages/bin
to your PATH
so commands you install globally are usable.
Add something like this to your .bashrc
file, then source ~/.bashrc
to reflect the change.
export PATH="$HOME/.npm-packages/bin:$PATH"
To install third party libraries defined in package.json
, run the
following within the airflow/www_rbac/
directory which will install them in a
new node_modules/
folder within www_rbac/
.
# from the root of the repository, move to where our JS package.json lives
cd airflow/www_rbac/
# run npm install to fetch all the dependencies
npm install
To parse and generate bundled files for airflow, run either of the
following commands. The dev
flag will keep the npm script running and
re-run it upon any changes within the assets directory.
# Compiles the production / optimized js & css
npm run prod
# Start a web server that manages and updates your assets as you modify them
npm run dev
Should you add or upgrade a npm package, which involves changing package.json
, you'll need to re-run npm install
and push the newly generated package-lock.json
file so we get the reproducible build.
We try to enforce a more consistent style and try to follow the JS community guidelines. Once you add or modify any javascript code in the project, please make sure it follows the guidelines defined in Airbnb JavaScript Style Guide. Apache Airflow uses ESLint as a tool for identifying and reporting on patterns in JavaScript, which can be used by running any of the following commands.
# Check JS code in .js and .html files, and report any errors/warnings
npm run lint
# Check JS code in .js and .html files, report any errors/warnings and fix them if possible
npm run lint:fix