Document the HTTP_ALL_INTERFACES feature

README.md

@@ -127,18 +127,32 @@ You should see the front page of the app (or the raw HTML with curl).
 ##### 8. Remote access via HTTPS
 This app listens for HTTP requests on the looback interface (default port 3000).  It can be reverse proxied by Nginx (which can proxy the HTTP as HTTPS), or accessed over an SSH tunnel as described below.
 
+The app can be made to listen on all interfaces for HTTP requests by setting HTTP_ALL_INTERFACES in the .env file, e.g.:
+```
+HTTP_ALL_INTERFACES=yes
+```
+Note that HTTP traffic is unencrypted, so this should only be done on a secure network, otherwise usernames and passwords will be exposed in plain text over the network.
+
 The app can be made to listen on all interfaces for HTTPS requests by specifying HTTPS_PORT in the .env file, e.g.:
 ```
 HTTPS_PORT=3443
 ```
-If HTTPS_PORT is not specified, then the app will only listen for HTTP requests on localhost.
-
 The app can be made to listen on a specific interface for HTTPS requests by specifying HTTPS_HOST (the host name or IP address of the interface) in the .env file, e.g.:
 ```
 HTTPS_HOST=12.34.56.78
 ```
 If HTTPS_HOST is not specified, but HTTPS_PORT is specified, then the app will listen for HTTPS requests on all interfaces.
 
+###### Summary of listening states
+| Environment variable | Protocol | Listen On      | Port              |
+| :------------------: | :------: | :-------:      | :--:              |
+| [none]               | HTTP     | localhost      | 3000              |
+| HTTP_PORT            | HTTP     | localhost      | HTTP_PORT         |
+| HTTP_ALL_INTERFACES  | HTTP     | all interfaces | HTTP_PORT || 3000 |
+| HTTPS_PORT           | HTTPS    | all interfaces | HTTPS_PORT        |
+| HTTPS_HOST           | HTTPS    | HTTPS_HOST     | HTTPS_PORT        |
+
+
 ###### TLS Certificate
 For HTTPS you obviously need a TLS (SSL) certificate and private key pair.  There are a few options:
 

src/bin/www

@@ -30,17 +30,23 @@ app.set('https_port', https_port);
 const https_host = process.env.HTTPS_HOST || null;
 app.set('https_host', https_host);
 
-/**
- * Create HTTPS server and listen on localhost only for HTTP, unless the 
- * environment variable HTTP_ALL_INTERFACES is set, and
- * on all network interfaces for HTTPS if HTTPS_PORT is set in env,
- * or on specific interface if HTTPS_HOST is set in env.
+/** Create HTTPS server and listen for protocols on interfaces and ports
+ *  according to environment variables as follows:
+ *  Environment variable    Protocol    Listen On       Port
+ *  --------------------    --------    ---------       ----
+ *  <none>                  HTTP        localhost       3000
+ *  HTTP_PORT               HTTP        localhost       HTTP_PORT
+ *  HTTP_ALL_INTERFACES     HTTP        all interfaces  HTTP_PORT || 3000
+ *  HTTPS_PORT              HTTPS       all interfaces  HTTPS_PORT
+ *  HTTPS_HOST              HTTPS       HTTPS_HOST      HTTPS_PORT
  */
 
-const http_all_int = process.env.HTTP_ALL_INTERFACES || null;
-if (http_all_int) {
+const http_all_interfaces = process.env.HTTP_ALL_INTERFACES || null;
+if (http_all_interfaces) {
+    console.log('Listening for HTTP requests on port ' + http_port + ' on all interfaces');
     app.listen(http_port);  
 } else {
+    console.log('Listening for HTTP requests on port ' + http_port + ' on localhost');
     app.listen(http_port, 'localhost');
 }
 

src/package.json

@@ -1,6 +1,6 @@
 {
   "name": "ztncui",
-  "version": "0.4.1",
+  "version": "0.4.2",
   "private": true,
   "scripts": {
     "start": "node ./bin/www",