Load extensions on demand using env variable

README.md

@@ -1,7 +1,7 @@
 # Docker Guacamole
 
 A Docker Container for [Apache Guacamole](https://guacamole.incubator.apache.org/), a clientless remote desktop gateway. It supports standard protocols like VNC, RDP, and SSH over HTML5.
-  
+
 [![IMAGE ALT TEXT](http://img.youtube.com/vi/esgaHNRxdhY/0.jpg)](http://www.youtube.com/watch?v=esgaHNRxdhY "Video Title")
 
 This container runs the guacamole web client, the guacd server and a postgres database.
@@ -21,6 +21,30 @@ The parameters are split into two halves, separated by a colon, the left hand si
 
 * `-p 8080:8080` - Binds the service to port 8080 on the Docker host, **required**
 * `-v /config` - The config and database location, **required**
+* `-e EXTENSIONS` - See below for details.
+
+## Enabling Extensions
+
+Extensions can be enabled using the `-e EXTENSIONS` variable. Multiple extensions can be enabled using a comma separated list without spaces.
+
+For example:
+
+```shell
+docker run \
+  -p 8080:8080 \
+  -v </path/to/config>:/config \
+  -e "EXTENSIONS=auth-ldap,auth-duo"
+  oznu/guacamole
+```
+
+Currently the available extensions are:
+
+* auth-ldap - [LDAP Authentication](https://guacamole.incubator.apache.org/doc/0.9.13-incubating/gug/ldap-auth.html)
+* auth-duo - [Duo two-factor authentication](https://guacamole.incubator.apache.org/doc/0.9.13-incubating/gug/duo-auth.html)
+* auth-header - [HTTP header authentication](https://guacamole.incubator.apache.org/doc/0.9.13-incubating/gug/header-auth.html)
+* auth-cas - [CAS Authentication](https://guacamole.incubator.apache.org/doc/0.9.13-incubating/gug/cas-auth.html)
+
+You should only enable the extensions you require, if an extensions is not configured correctly in the `guacamole.properties` file it may prevent the system from loading. See the [official documentation](https://guacamole.incubator.apache.org/doc/0.9.13-incubating/gug/) for more details.
 
 ## Default User