sql_alchemy_conn = postgresql+psycopg2://username:password@192.168.2.12:5432/airflow
executor = CeleryExecutor
broker_url = amqp://username:password@192.168.1.12:5672//
celery_result_backend = db+postgresql://username:password@192.168.2.12:5432/airflow

RabbitMQ is running
Can connect to PostgreSQL and have confirmed that Airflow has created tables
Can start and view the webserver (including custom dags)

sql_alchemy_conn = postgresql+psycopg2://username:password@192.168.2.12:5432/airflow
executor = CeleryExecutor
broker_url = amqp://username:password@192.168.1.12:5672//
celery_result_backend = db+postgresql://username:password@192.168.2.12:5432/airflow

[2018-02-19 14:58:14,276] {__init__.py:57} INFO - Using executor CeleryExecutor
[2018-02-19 14:58:14,360] {driver.py:120} INFO - Generating grammar tables from /usr/lib/python3.5/lib2to3/Grammar.txt
[2018-02-19 14:58:14,384] {driver.py:120} INFO - Generating grammar tables from /usr/lib/python3.5/lib2to3/PatternGrammar.txt
[I 180219 14:58:15 command:139] Visit me at http://0.0.0.0:5555
[I 180219 14:58:15 command:144] Broker: amqp://username:password@192.168.1.12:5672//
[I 180219 14:58:15 command:147] Registered tasks:
    ['celery.accumulate',
     'celery.backend_cleanup',
     'celery.chain',
     'celery.chord',
     'celery.chord_unlock',
     'celery.chunks',
     'celery.group',
     'celery.map',
     'celery.starmap']
[I 180219 14:58:15 mixins:224] Connected to amqp://username:password@192.168.1.12:5672//