Updated docs for Systemd and Supervisor. #21

docs/installation-production.md

@@ -8,7 +8,7 @@
     - [Configuration](#configuration)
     - [Running Engine](#running-engine)
         - [Running with Systemd](#running-with-systemd)
-            - [Combined Unit for Engine Core and Liquidsoap](#combined-unit-for-engine-core-and-liquidsoap)
+            - [Run the Engine with a single command](#run-the-engine-with-a-single-command)
             - [Individual Units for Engine Core and Liquidsoap](#individual-units-for-engine-core-and-liquidsoap)
         - [Running with Supervisor](#running-with-supervisor)
     - [Logging](#logging)
@@ -149,7 +149,7 @@ In your production environment edit following file to configure the engine:
 engineuser:/opt/aura/engine$ nano /etc/aura/engine.ini
 ```
 
-Now, specify at least following settings to get started:
+Now, specify at least the following settings to get started:
 
 ```ini
     [database]
@@ -158,7 +158,7 @@ Now, specify at least following settings to get started:
     db_pass="---SECRET--PASSWORD---"
 ```
 
-Set the URLs to the *Steering*, *Tank* and *Engine* API:
+Define the API URLs to the *Steering*, *Tank* and *Engine API*:
 
 ```ini
 [api]
@@ -225,54 +225,41 @@ For this you can utilize either [Systemd](https://systemd.io/) or [Supervisor](h
 
 ### Running with Systemd
 
-
-#### Combined Unit for Engine Core and Liquidsoap
-
-Copy the unit file `/opt/aura/engine/config/systemd/aura-engine.service` to `/etc/systemd/system/`.
-
-This unit file starts engine-core and engine-liquidsoap within one command. Here Liquidsoap is started as
-as subprocess. For more fine-grained control the units in the next section are recommended instead.
-
-Now you'll need to reload the Systemd unit files
+Copy the unit files in  `/opt/aura/engine/config/systemd/aura-engine.service` to your systemd unit directory,
+and reload the systemd daemon:
 
 ```shell
-sudo systemctl daemon-reload
+cp /opt/aura/engine/config/systemd/* /etc/systemd/system/
+systemctl daemon-reload
 ```
 
-**Start**
-
-```shell
-sudo systemctl start aura-engine
-```
+#### Run the Engine with a single command
 
-**Stop**
-
-```shell
-sudo systemctl start aura-engine
-```
+This unit file starts engine-core and engine-liquidsoap within one command. Here Liquidsoap is started as
+as subprocess. For more fine-grained control the units in the next section are recommended instead.
 
-**Restart**
+The most common way to start the engine is using the combined command which starts Liquidsoap (`aura-engine-lqs`)
+and the Engine Core:
 
 ```shell
-sudo systemctl restart aura-engine
+systemctl start aura-engine
 ```
 
-**Status**
+Now you are able to stop and restart the scheduler without affecting the playout of Liquidsoap. Note, Liquidsoap
+will play as long it has already scheduled data for the current timeslot. If it doesn't it will still the defined
+station fallback scenario.
 
 ```shell
-sudo systemctl status aura-engine
+systemctl restart aura-engine
+systemctl stop aura-engine
+systemctl status aura-engine
 ```
 
 #### Individual Units for Engine Core and Liquidsoap
 
-Copy the unit files `/opt/aura/engine/config/systemd/aura-engine-lqs.service` and
-`/opt/aura/engine/config/systemd/aura-engine-core.service` to `/etc/systemd/system/`.
-
-Now you'll need to reload the Systemd unit files
-
-```shell
-sudo systemctl daemon-reload
-```
+If you prefer to start both Engine components individually you can use the units `aura-engine-core` and
+`aura-engine-lqs`. But keep in mind there is no dependency between those units. If you start Engine Core
+the Liquidsoap part will not be started by itself and vice versa.
 
 **Start Liquidsoap and check its status**
 
@@ -294,7 +281,6 @@ sudo systemctl status aura-engine-core
 sudo journalctl -f
 ```
 
-
 ### Running with Supervisor
 
 Now, given you are in the engine's home directory `/opt/aura/engine/`, simply type following to start
@@ -307,7 +293,7 @@ supervisord
 This picks up the supervisor configuration provided in the local `supervisord.conf` and the service configurations
 located in `config/supervisor/*.conf`.
 
-Experience has shown it might be helpful to reload the supervisor configuration using `sudo`:
+Then you'll need to reload the supervisor configuration using `sudo`:
 
 ```shell
 sudo supervisorctl reload
@@ -326,7 +312,7 @@ You should get these all services with their actual state listed:
 
 ```c++
 aura-engine                      in use    auto      666:666
-aura-engine-api                  in use    auto      999:999
+aura-engine-lqs                  in use    auto      999:999
 ```
 
 **Maintanence using Supervisor**
@@ -334,32 +320,15 @@ aura-engine-api                  in use    auto      999:999
 Please remember to call all `supervisorctl` commands from within your engine home directory (`/opt/aura/engine/`),
 to pickup the correct `supervisord.conf`.
 
-**Starting Services**
+**Starting, stopping and restarting a service**
 
 ```shell
     supervisorctl start <service-name>
-```
-
-**Stopping Services**
-
-```shell
     supervisorctl stop <service-name>
-
-```
-
-**Restarting Services**
-
-```shell
-    supervisorctl restart <service-name>
-```
-
-**Refresh after changing configurations**
-
-```shell
     supervisorctl restart <service-name>
 ```
 
-In case you want to reload whole supervisor service
+**Reloading the whole supervisor service**
 
 ```shell
     sudo service supervisor restart