Rework(docker-config): Take configurable variables from environment

- To be able to configure the compoment without having to add the engine.ini to the meta repository,
	the docker image now expects configurable variable to be passed as environment variables

config/sample-docker.engine.ini

@@ -8,99 +8,99 @@ socket_dir="/srv/socket"
 # Directory where the log file resides
 log_dir="logs"
 # Possible values: debug, info, warning, error, critical
-log_level="info"
+log_level="${ENGINE_LOG_LEVEL}"
 
 [monitoring]
 # Mail server credentials for sending email notifications (Admin and Programme Coordination)
-mail_server="mail.your-radio.org"
-mail_server_port="587"
-mail_user="aura@subsquare.at"
-mail_pass="---SECRET--PASSWORD---"
+mail_server="${ENGINE_MONITORING_MAIL_SERVER}"
+mail_server_port="${ENGINE_MONITORING_MAIL_SERVER_PORT}"
+mail_user="${ENGINE_MONITORING_MAIL_USER}"
+mail_pass="${ENGINE_MONITORING_MAIL_PASSWORD}"
 # Set to "true" if you want to notify programme-coordinators about about fallback situations, otherwise "false"
-mail_coordinator_enabled="false"
+mail_coordinator_enabled="${ENGINE_MONITORING_MAIL_COORDINATOR_ENABLED}"
 # If you want to address multiple programme-coordinators separate their emails by space
-coordinator_mail="programme-coordinator@your-radio.org"
+coordinator_mail="${ENGINE_MONITORING_COORDINATOR_MAIL}"
 # Set to "true" if you want to notify admins about incidents, otherwise "false"
-mail_admin_enabled="false"
+mail_admin_enabled="${ENGINE_MONITORING_ADMIN_MAIL_ENABLED}"
 # If you want to address multiple administrators separate their emails by space
-admin_mail="admin@your-radio.org"
+admin_mail="${ENGINE_MONITORING_ADMIN_MAIL}"
 # The FROM email address used when sending
-from_mail="monitoring@aura.engine"
+from_mail="${ENGINE_MONITORING_SENDER_MAILADDRESS}"
 # A subject prefix allows applying filter rules in your mail client
-mailsubject_prefix="[AURA Engine]"
+mailsubject_prefix="${ENGINE_MONITORING_MAIL_SUBJECT_PREFIX}" # default: [AURA Engine]
 
-# Server where heartbeat info is sent to
-heartbeat_server = "127.0.0.1"
+# Server where heartbeat info is sent to 
+heartbeat_server="${ENGINE_HEARTBEAT_SERVER}"
 # Some UDP port
-heartbeat_port = 43334
+heartbeat_port=${ENGINE_HEARTBEAT_SERVER_PORT}
 # Seconds how often the vitality of the Engine should be checked (0 = disabled)
-heartbeat_frequency = 1
+heartbeat_frequency=${ENGINE_HEARTBEAT_FREQUENCY}
 
 [api]
 ## STEERING ##
 # The URL to get the health status
-api_steering_status="http://127.0.0.1:8000/api/v1/"
+api_steering_status="${STEERING_BASE_URL}api/v1/"
 # The URL to get the Calendar via Steering
-api_steering_calendar="http://127.0.0.1:8000/api/v1/playout"
+api_steering_calendar="${STEERING_BASE_URL}api/v1/playout"
 
 ## TANK ##
 # The session name which is used to authenticate against Tank
-api_tank_session="engine"
+api_tank_session="${ENGINE_TANK_SESSION}"
 # The secret which is used to authenticate against Tank
-api_tank_secret="rather-secret"
+api_tank_secret="${ENGINE_TANK_SECRET}"
 # The URL to get the health status
-api_tank_status="http://127.0.0.1:8040/healthz/"
+api_tank_status="${TANK_BASE_URL}healthz/"
 # The URL to get playlist details via Tank
-api_tank_playlist="http://127.0.0.1:8040/api/v1/playlists/${ID}"
+api_tank_playlist="${TANK_BASE_URL}api/v1/playlists/${ID}"
 
 ## ENGINE-API ##
 # Engine ID (1 or 2)
 api_engine_number=1
 # Engine API availability check
-api_engine_status="http://127.0.0.1:8008/api/v1/ui/"
+api_engine_status="${ENGINE_API_BASE_URL}api/v1/ui/"
 # Engine API endpoint to store playlogs
-api_engine_store_playlog="http://127.0.0.1:8008/api/v1/playlog"
+api_engine_store_playlog="${ENGINE_API_BASE_URL}api/v1/playlog"
 # Engine API endpoint to store clock information
-api_engine_store_clock="http://127.0.0.1:8008/api/v1/clock"
+api_engine_store_clock="${ENGINE_API_BASE_URL}api/v1/clock"
 # Engine API endpoint to store health information
-api_engine_store_health="http://127.0.0.1:8008/api/v1/source/health/${ENGINE_NUMBER}"
+api_engine_store_health="${ENGINE_API_BASE_URL}api/v1/source/health/${ENGINE_NUMBER}"
 
 ## ENGINE-CORE ##
 # Host and port of the local engine backchannel (Network Socket for e.g. sending track service updates)
 api_engine_control_host="0.0.0.0:1337"
 
 [scheduler]
-# Database settings: Use 'postgresql', 'sqlite' or 'mysql'. In case of SQLite the "db_name" is the name of the file.
+# Database settings: Use 'postgresql' or 'mysql'
 db_type="postgresql"
-db_name="aura_engine"
-db_user="aura_engine"
-db_pass="---SECRET--PASSWORD---"
-db_host="127.0.0.1"
+db_name="${ENGINE_DB_NAME}"
+db_user="${ENGINE_DB_USER}"
+db_pass="${ENGINE_DB_PASS}"
+db_host="engine-postgres"
 db_charset="utf8"
 # Base path as seen by "engine-core", not accessed by "engine"; this is required to construct the absolute audio file path (check "Audio Store" in the docs)
 # Either provide an absolute base path or a relative one starting in the `engine-core/src` directory. In case of `engine-core` running in docker use `/var/audio/source`
-audio_source_folder="/var/audio/source"
-audio_source_extension=".flac"
+audio_source_folder="${ENGINE_AUDIO_SOURCE_FOLDER}"
+audio_source_extension="${ENGINE_AUDIO_SOURCE_EXTENSION}"
 # Folder holding M3U Playlists to be scheduled in form of Engine Playlists (similar as audio source folder above)
-audio_playlist_folder="/var/audio/playlist"
+audio_playlist_folder="${ENGINE_AUDIO_PLAYLIST_FOLDER}"
 # Offset in seconds how long it takes for Liquidsoap to actually execute a scheduler command; Crucial to keep things in sync
-engine_latency_offset=0.5
+engine_latency_offset=${ENGINE_LATENCY_OFFSET}
 # How often should the calendar be fetched in seconds. This determines the time of the last changes applied, before a specific show is aired
-fetching_frequency=30
+fetching_frequency=${ENGINE_FETCHING_FREQUENCY}
 # The scheduling window defines when the entries of each timeslot are queued for play-out. The windows start at (timeslot.start - window_start) seconds
 # and ends at (timeslot.end - window.end) seconds. Its also worth noting, that timeslots can only be deleted before the start of the window.
-scheduling_window_start=60
-scheduling_window_end=60
+scheduling_window_start=${ENGINE_SCHEDULING_WINDOW_START}
+scheduling_window_end=${ENGINE_SCHEDULING_WINDOW_END}
 # How many seconds before the actual schedule time the entry should be pre-rolled. Note to provide enough timeout for
 # contents which take longer to load (big files, bad connectivity to streams etc.). If the planned start time is in
 # the past the offset is ignored and the entry is played as soon as possible
-preload_offset=15
+preload_offset=${ENGINE_PRELOAD_OFFSET}
 # Sometimes it might take longer to get a stream connected. Here you can define a viable length.
 # But note, that this may affect the preloading time (see `preload_offset`), hence affecting the
-# overall playout, its delays and possible fallbacks
-input_stream_retry_delay=1
-input_stream_max_retries=10
-input_stream_buffer=3.0
+# overall playout, it's delays and possible fallbacks
+input_stream_retry_delay=${ENGINE_INPUT_STREAM_RETRY_DELAY}
+input_stream_max_retries=${ENGINE_INPUT_STREAM_MAX_RETRIES}
+input_stream_buffer=${ENGINE_INPUT_STREAM_BUFFER}
 # How long we have to fade in and out, when we select another mixer input (seconds))
-fade_in_time="1.5"
-fade_out_time="1.5"
+fade_in_time="${ENGINE_FADE_IN_TIME}"
+fade_out_time="${ENGINE_FADE_OUT_TIME}"