allow authentication against mqtt server

src/config.rs

@@ -1,5 +1,6 @@
 use crate::device::BDAddr;
 use color_eyre::{eyre::WrapErr, Report, Result};
+use rumqttc::MqttOptions;
 use std::collections::BTreeMap;
 use std::str::FromStr;
 
@@ -9,6 +10,12 @@ pub struct Config {
     pub mqtt_port: u16,
     pub host_port: u16,
     pub mi_temp_names: BTreeMap<BDAddr, String>,
+    pub mqtt_credentials: Option<Credentials>,
+}
+
+pub struct Credentials {
+    username: String,
+    password: String,
 }
 
 impl Config {
@@ -40,11 +47,37 @@ impl Config {
             })
             .collect::<Result<BTreeMap<BDAddr, String>, Report>>()?;
 
+        let mqtt_credentials = match dotenv::var("MQTT_USERNAME") {
+            Ok(username) => {
+                let password = dotenv::var("MQTT_PASSWORD")
+                    .wrap_err("MQTT_USERNAME set, but MQTT_PASSWORD not set")?;
+                Some(Credentials { username, password })
+            }
+            Err(_) => None,
+        };
+
         Ok(Config {
             mqtt_host,
             mqtt_port,
             host_port,
             mi_temp_names,
+            mqtt_credentials,
         })
     }
+
+    pub fn mqtt(&self) -> Result<MqttOptions> {
+        let hostname = hostname::get()?
+            .into_string()
+            .map_err(|_| Report::msg("invalid hostname"))?;
+        let mut mqtt_options = MqttOptions::new(
+            format!("taspromto-{}", hostname),
+            &self.mqtt_host,
+            self.mqtt_port,
+        );
+        if let Some(credentials) = self.mqtt_credentials.as_ref() {
+            mqtt_options.set_credentials(&credentials.username, &credentials.password);
+        }
+        mqtt_options.set_keep_alive(5);
+        Ok(mqtt_options)
+    }
 }

src/main.rs

@@ -7,10 +7,10 @@ use crate::config::Config;
 use crate::device::{format_device_state, Device, DeviceState};
 use crate::mqtt::mqtt_stream;
 use crate::topic::Topic;
-use color_eyre::{eyre::WrapErr, Report, Result};
+use color_eyre::{eyre::WrapErr, Result};
 use dashmap::DashMap;
 use pin_utils::pin_mut;
-use rumqttc::{MqttOptions, QoS};
+use rumqttc::QoS;
 use std::sync::Arc;
 use tokio::stream::StreamExt;
 use tokio::time::Duration;
@@ -31,11 +31,10 @@ async fn main() -> Result<()> {
     .expect("Error setting Ctrl-C handler");
 
     let states = device_states.clone();
-    let mqtt_host = config.mqtt_host;
-    let mqtt_port = config.mqtt_port;
+    let mi_temp_names = config.mi_temp_names.clone();
     tokio::task::spawn(async move {
         loop {
-            if let Err(e) = mqtt_client(&mqtt_host, mqtt_port, states.clone()).await {
+            if let Err(e) = mqtt_client(&config, states.clone()).await {
                 eprintln!("lost mqtt collection: {:#}", e);
             }
             eprintln!("reconnecting after 1s");
@@ -45,7 +44,6 @@ async fn main() -> Result<()> {
 
     let state = warp::any().map(move || device_states.clone());
 
-    let mi_temp_names = config.mi_temp_names;
     let metrics = warp::path!("metrics")
         .and(state)
         .map(move |state: DeviceStates| {
@@ -66,12 +64,8 @@ async fn main() -> Result<()> {
     Ok(())
 }
 
-async fn mqtt_client(host: &str, port: u16, device_states: DeviceStates) -> Result<()> {
-    let hostname = hostname::get()?
-        .into_string()
-        .map_err(|_| Report::msg("invalid hostname"))?;
-    let mut mqtt_options = MqttOptions::new(format!("taspromto-{}", hostname), host, port);
-    mqtt_options.set_keep_alive(5);
+async fn mqtt_client(config: &Config, device_states: DeviceStates) -> Result<()> {
+    let mqtt_options = config.mqtt()?;
 
     let (client, stream) = mqtt_stream(mqtt_options)
         .await