Add note about conf via env vars

README.md

@@ -36,6 +36,11 @@ docker build . -t ghostream
 docker run -it --rm -p 2112:2112 -p 9710:9710/udp -p 8080:8080 -p 10000-10005:10000-10005/udp ghostream
 ```
 
+## Configuration
+
+Ghostream can be configured by placing [ghostream.yml](docs/ghostream.example.yml) in current directory, in `~/.ghostream/` or in `/etc/ghostream/`.
+You can also override any value using environnement variables, e.g. `GHOSTREAM_AUTH_BACKEND=ldap` will change the authentification backend.
+
 ## Streaming
 
 As stated by OBS wiki, when streaming you should adapt the latency to `2.5 * (the round-trip time with server, in μs)`.

docs/ghostream.example.yml

@@ -1,5 +1,8 @@
 ## Example Ghostream configuration ##
 # Uncomment and edit to change values
+#
+# All settings can also be changed with an environnement variable,
+# e.g. GHOSTREAM_AUTH_BACKEND=ldap will change auth.backend to "ldap"
 
 ## Authentification package ##
 # Manage incoming stream authentification