Move configuration into the unit file

README.md

@@ -11,7 +11,7 @@ another system.
 
 ## git-monitor
 
-The git-monitor is a system service, that monitors a target directory on the
+The git-monitor is a system service that monitors a target directory on the
 PiDP-10. It contains a file with a list of git repositories to monitor, one at a
 time. The service will check if any of the repositories changed, and pull them.
 After a successful pull a script will be called, if it exists, that allows the
@@ -36,3 +36,49 @@ service to be enabled on system boot, enable the service:
 ```bash
 sudo systemctl enable git-monitor.service
 ```
+
+### Configuration
+
+The service is usable immediately after installation. The service is configured
+through a series of environment variables, that can be set to change the default
+behaviour. There are five different environment variables to configure the
+service with:
+
+<table>
+  <tr>
+    <th>Environment Variable</th>
+    <th>Description</th>
+    <th>Default Value</th>
+  </tr>
+  <tr>
+    <td>GITMONITOR_URLS</td>
+    <td>A file that contains the list of observed repositories in a directory by name and URL.</td>
+    <td>/opt/src/repository.list</td>
+  </tr>
+  <tr>
+    <td>GITMONITOR_LOCAL_PATH</td>
+    <td>The path in which the clone repositories will be stored.</td>
+    <td>/opt/src</td>
+  </tr>
+  <tr>
+    <td>GITMONITOR_BRANCH_NAME</td>
+    <td>The name of the branch to observe.</td>
+    <td>develop</td>
+  </tr>
+  <tr>
+    <td>GITMONITOR_POLL_INTERVALL</td>
+    <td>The number of seconds to wait until the next poll.</td>
+    <td>30</td>
+  </tr>
+  <tr>
+    <td>GITMONITOR_LOCK_FILE</td>
+    <td>The lock file that is used to monitor the service. </td>
+    <td>/run/lock/git-monitor.lock</td>
+  </tr>
+</table>
+
+You can override these settings by creating an override file for the service
+unit. Create a new file
+`/etc/serviced/service/git-monitor.service.d/override.conf` by typing
+`sudo systemctl edit git-monitor.service`. You can then uncomment the
+`Environment` statements, and change the value of the variables accordingly.