Multiple changes and documentation.

README.md

@@ -16,9 +16,63 @@ Sinatra provides for this simple use case:
 - A Dockerfile (and docker-compose) to encapsulate the server within a docker container.
 - Optional default VLAN support to support unknown MAC addresses, e.g. into a guest network.
 
+# Configuration
+
+Optional configuration is via environment variables.
+
+### SINATRA_PORT_RADIUS_AUTH
+Sets the listening port for RADIUS authentication.
+
+Default: 1812
+
+### SINATRA_PORT_RADIUS_ACCT
+Sets the listening port for RADIUS accounting
+
+Default: 1813
+
+### SINATRA_PORT_API
+Sets the listening port for the API
+
+Default: 8088
+
+### SINATRA_STORAGE
+Sets the storage type and location for data. The format is type://location.
+
+Supported types are:
+
+##### json
+Uses a serialised JSON data file. e.g. json://./data
+
+Default: json://./data
+
+### SINATRA_CLIENT_SECRET
+Sets the shared secret for RADIUS clients
+
+Default: password
+
+### SINATRA_DEFAULT_VLAN
+Sets the default VLAN ID for unauthenticated users. If false, users must pass authentication.
+
+Default: false
+
+### SINATRA_MAC_AUTH_ONLY
+Sets whether usernames and passwords should be processed as MAC addresses.  
+If true, then all input formats are normalised to lowercase alphanumeric strings, e.g. aabbccddeeff
+
+Default: false
+
+### SINATRA_SESSION_DURATION
+Sets the RADIUS session duration in minutes.
+
+Default: 60
+
+### SINATRA_TIME_RULES
+Sets whether time rules are to be processed.  
+If true, then all registered users must have at least one 'allow' rule defined.
+
+Default: false
+
 # Feature roadmap
 
 - Mass-import from CSV
-- Time-based authentication
-- Time-limited access
 - Connection accounting (with REST API endpoints for data access)