Added functionality to automatically ingest custom airflow.cfg file upon startup

docs/apache-airflow/howto/docker-compose/docker-compose.yaml

@@ -41,7 +41,7 @@
 #                                A better way is to build a custom image or extend the official image
 #                                as described in https://airflow.apache.org/docs/docker-stack/build.html.
 #                                Default: ''
-#
+# 
 # Feel free to modify this file to suit your needs.
 ---
 x-airflow-common:
@@ -69,11 +69,15 @@
     # WARNING: Use _PIP_ADDITIONAL_REQUIREMENTS option ONLY for a quick checks
     # for other purpose (development, test and especially production usage) build/extend Airflow image.
     _PIP_ADDITIONAL_REQUIREMENTS: ${_PIP_ADDITIONAL_REQUIREMENTS:-}
+    #The following line can be used to set a custom config file, stored in the local config folder
+    #If you want to use it, outcomment it and replace airflow.cfg with the name of your config file
+    #AIRFLOW_CONFIG: '/opt/airflow/config/airflow.cfg'
   volumes:
     - ${AIRFLOW_PROJ_DIR:-.}/dags:/opt/airflow/dags
     - ${AIRFLOW_PROJ_DIR:-.}/logs:/opt/airflow/logs
     - ${AIRFLOW_PROJ_DIR:-.}/config:/opt/airflow/config
     - ${AIRFLOW_PROJ_DIR:-.}/plugins:/opt/airflow/plugins
+
   user: "${AIRFLOW_UID:-50000}:0"
   depends_on:
     &airflow-common-depends-on

docs/apache-airflow/howto/docker-compose/index.rst

@@ -340,6 +340,19 @@ that conflicts with the version of apache-airflow that you are using.
 Run ``docker compose build`` to build the image, or add ``--build`` flag to ``docker compose up`` or
 ``docker compose run`` commands to build the image automatically as needed.
 
+Special case - Adding a custom config file
+==========================================
+
+If you have a custom config file and wish to use it in your Airflow instance, you need to perform the following steps:
+
+1) Remove comment from the ``AIRFLOW_CONFIG: '/opt/airflow/config/airflow.cfg'`` line 
+   in the ``docker-compose.yaml`` file.  
+
+2) Place your custom ``airflow.cfg`` file in the local config folder.
+
+3) If your config file has a different name than ``airflow.cfg``, adjust the filename in 
+   ``AIRFLOW_CONFIG: '/opt/airflow/config/airflow.cfg'``
+
 Networking
 ==========