Added DSM_HOSTNAME variable support (#38)

README.md

@@ -147,3 +147,7 @@ services:
 ### 1. Verify your config.json and package.json syntax
 
 Many issues appear because of invalid JSON. A good way to verify your config is to use the [jsonlint.com](http://jsonlint.com/) validator.
+
+### 2. When running on Synology DSM set the `DSM_HOSTNAME` environment variable
+
+You may need to provide the server name of your Synology NAS using the `DSM_HOSTNAME` environment variable to prevent [hostname conflict errors](https://github.com/oznu/docker-homebridge/issues/35). The value of the `DSM_HOSTNAME` environment should exactly match the server name as shown under `Synology DSM Control Panel` -> `Info Centre` -> `Server name`, it should contain no spaces or special characters.

root/etc/avahi/avahi-daemon.conf → root/defaults/avahi-daemon.conf

@@ -1,4 +1,5 @@
 [server]
+#host-name=
 use-ipv4=yes
 use-ipv6=no
 enable-dbus=yes

root/etc/cont-init.d/40-dbus → root/etc/cont-init.d/40-dbus-avahi

@@ -13,3 +13,13 @@ chown messagebus:messagebus /var/run/dbus
 chown avahi:avahi /var/run/avahi-daemon
 dbus-uuidgen --ensure
 sleep 1
+
+# avahi config
+cp /defaults/avahi-daemon.conf /etc/avahi/avahi-daemon.conf
+
+# fix for synology dsm - see #35
+if [[ ! -z "$DSM_HOSTNAME" ]]; then
+  sed -i "s/.*host-name.*/host-name=${DSM_HOSTNAME}/" /etc/avahi/avahi-daemon.conf
+else
+  sed -i "s/.*host-name.*/#host-name=/" /etc/avahi/avahi-daemon.conf
+fi