Improve MQTT documentation, example config

Also print an error message when the configuration isn't present but the `mqtt` subcommand is used. Without this, the program just exits without any messsages.

.vscode/launch.json

@@ -0,0 +1,18 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug",
+            "program": "${workspaceRoot}/target/debug/${workspaceRootFolderName}",
+            "args": ["mqtt", "--config", "target/config.toml"],
+            "cwd": "${workspaceRoot}",
+            "sourceLanguages": [
+                "rust"
+            ],
+            "env": {
+                "RUST_LOG": "debug"
+            }
+        }
+    ]}

sample_config.toml

@@ -35,6 +35,10 @@ name = "driveway"
 username = "admin"
 password = "12345678"
 address = "192.168.1.187:9000"
+# mqtt.broker_addr = "192.168.1.122"
+# mqtt.port = 1883
+# mqtt.credentials = ["mqtt_user", "mqtt_password"]
+
 # If you use a battery camera: **Instead** of an `address` supply the uid
 # as follows
 # uid = "ABCD01234567890EFG"

src/mqtt/cmdline.rs

@@ -1,5 +1,4 @@
 use structopt::StructOpt;
 
-/// The reboot command will reboot the camera
 #[derive(StructOpt, Debug)]
 pub struct Opt {}

src/mqtt/mod.rs

@@ -1,15 +1,13 @@
 use log::*;
 ///
-/// # Neolink Reboot
+/// # Neolink MQTT
 ///
-/// This module handles the reboot subcommand
-///
-/// The subcommand attepts to reboot the camera.
+/// Handles incoming and outgoing MQTT messages
 ///
 /// # Usage
 ///
 /// ```bash
-/// neolink reboot --config=config.toml CameraName
+/// neolink mqtt --config=config.toml
 /// ```
 ///
 use std::sync::Arc;
@@ -34,11 +32,14 @@ pub(crate) fn main(_: Opt, config: Config) -> Result<()> {
     let app = App::new();
     let arc_app = Arc::new(app);
 
+    let mut mqtt_count: u8 = 0;
+
     let _ = crossbeam::scope(|s| {
         for camera_config in &config.cameras {
             if let Some(mqtt_config) = camera_config.mqtt.as_ref() {
                 let loop_arc_app = arc_app.clone();
                 info!("{}: Setting up mqtt", camera_config.name);
+                mqtt_count = mqtt_count + 1;
                 s.spawn(move |_| {
                     while loop_arc_app.running("app") {
                         let _ = listen_on_camera(camera_config, mqtt_config, loop_arc_app.clone());
@@ -48,6 +49,10 @@ pub(crate) fn main(_: Opt, config: Config) -> Result<()> {
         }
     });
 
+    if mqtt_count == 0 {
+        error!("MQTT command run, but no cameras configured with MQTT settings. Exiting.");
+    }
+
     Ok(())
 }