# INSTALL / BUILD instructions for Apache Airflow

This ia a generic installation method that requires a number of dependencies to be installed.

Depending on your system you might need different prerequisites, but the following
systems/prerequisites are known to work:

Linux (Debian Buster and Linux Mint Tricia):

sudo apt install build-essentials python3.6-dev python3.7-dev python-dev openssl \
                 sqlite sqlite-dev default-libmysqlclient-dev libmysqld-dev postgresq

MacOS (Mojave/Catalina):

brew install sqlite mysql postgresql

# [required] fetch the tarball and untar the source move into the directory that was untarred.

# [optional] run Apache RAT (release audit tool) to validate license headers
# RAT docs here: https://creadur.apache.org/rat/. Requires Java and Apache Rat
java -jar apache-rat.jar -E ./.rat-excludes -d .

# [optional] Airflow pulls in quite a lot of dependencies in order
# to connect to other services. You might want to test or run Airflow
# from a virtual env to make sure those dependencies are separated
# from your system wide versions

python3 -m venv PATH_TO_YOUR_VENV
source PATH_TO_YOUR_VENV/bin/activate

NOTE!!

On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
``--use-deprecated legacy-resolver`` to your pip install command.

# [required] building and installing by pip (preferred)
pip install .

# or directly
python setup.py install

# You can also install recommended version of the dependencies by using
# constraint-python<PYTHON_MAJOR_MINOR_VERSION>.txt files as constraint file. This is needed in case
# you have problems with installing the current requirements from PyPI.
# There are different constraint files for different python versions. For example"

pip install . \
  --constraint "https://raw.githubusercontent.com/apache/airflow/constraints-master/constraints-3.6.txt"


By default `pip install` in Airflow 2.0 installs only the provider packages that are needed by the extras and
install them as packages from PyPI rather than from local sources:


pip install . \
  --constraint "https://raw.githubusercontent.com/apache/airflow/constraints-master/constraints-3.6.txt"


You can also install airflow in "editable mode" (with -e) flag and then provider packages are
available directly from the sources (and the provider packages installed from PyPI are UNINSTALLED in
order to avoid having providers in two places. And `provider.yaml` files are used to discover capabilities
of the providers which are part of the airflow source code.

You can read more about `provider.yaml` and community-managed providers in
https://airflow.apache.org/docs/apache-airflow-providers/index.html for developing custom providers
and in ``CONTRIBUTING.rst`` for developing community maintained providers.

This is useful if you want to develop providers:

pip install -e . \
  --constraint "https://raw.githubusercontent.com/apache/airflow/constraints-master/constraints-3.6.txt"

You can als skip installing provider packages from PyPI by setting INSTALL_PROVIDERS_FROM_SOURCE to "true".
In this case Airflow will be installed in non-editable mode with all providers installed from the sources.
Additionally `provider.yaml` files will also be copied to providers folders which will make the providers
discoverable by Airflow even if they are not installed from packages in this case.

INSTALL_PROVIDERS_FROM_SOURCES="true" pip install . \
  --constraint "https://raw.githubusercontent.com/apache/airflow/constraints-master/constraints-3.6.txt"

Airflow can be installed with extras to install some additional features (for example 'async' or 'doc' or
to install automatically providers and all dependencies needed by that provider:

pip install .[async,google,amazon] \
  --constraint "https://raw.githubusercontent.com/apache/airflow/constraints-master/constraints-3.6.txt"

The list of available extras:

# START EXTRAS HERE

all, all_dbs, amazon, apache.atlas, apache.beam, apache.cassandra, apache.druid, apache.hdfs,
apache.hive, apache.kylin, apache.livy, apache.pig, apache.pinot, apache.spark, apache.sqoop,
apache.webhdfs, async, atlas, aws, azure, cassandra, celery, cgroups, cloudant, cncf.kubernetes,
crypto, dask, databricks, datadog, devel, devel_all, devel_ci, devel_hadoop, dingding, discord, doc,
docker, druid, elasticsearch, exasol, facebook, ftp, gcp, gcp_api, github_enterprise, google,
google_auth, grpc, hashicorp, hdfs, hive, http, imap, jdbc, jenkins, jira, kerberos, kubernetes,
ldap, microsoft.azure, microsoft.mssql, microsoft.winrm, mongo, mssql, mysql, neo4j, odbc, openfaas,
opsgenie, oracle, pagerduty, papermill, password, pinot, plexus, postgres, presto, qds, qubole,
rabbitmq, redis, s3, salesforce, samba, segment, sendgrid, sentry, sftp, singularity, slack,
snowflake, spark, sqlite, ssh, statsd, tableau, telegram, vertica, virtualenv, webhdfs, winrm,
yandex, zendesk

# END EXTRAS HERE

# For installing Airflow in development environments - see CONTRIBUTING.rst