Add $hostname variable substitution in config

This commit adds support for automatic hostname substitution in configuration files.
Users can now use $hostname in device.name, device.identifiers, and mqtt.client_id
to automatically use the system's hostname.

Changes:
- Add hostname crate dependency (v0.4)
- Implement expand_variables() to replace $hostname with actual hostname
- Add get_hostname() helper function
- Update config.example.yaml to demonstrate $hostname usage
- Add test for hostname substitution
- Update config.yaml to use $hostname by default
- Add test_command.sh script for testing MQTT commands

This makes deployment easier across multiple machines without manual config changes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

config/config.example.yaml

@@ -1,7 +1,11 @@
 # Codex created 2025-12-29_0224
+# Configuration example for Pilot v2
+# Special variables:
+#   $hostname - Will be replaced by the system hostname at runtime
+
 device:
-  name: pilot-device
+  name: $hostname  # Use $hostname for automatic hostname, or a custom name like "my-pc"
-  identifiers: ["pilot-device"]
+  identifiers: ["$hostname"]
 
 mqtt:
   host: "127.0.0.1"
@@ -10,7 +14,7 @@ mqtt:
   password: ""
   base_topic: "pilot"
   discovery_prefix: "homeassistant"
-  client_id: "pilot-device"
+  client_id: "$hostname"  # MQTT client ID - use $hostname or a custom ID
   keepalive_s: 60
   qos: 0
   retain_states: true

pilot-v2/Cargo.lock

@@ -672,6 +672,17 @@ version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 
+[[package]]
+name = "hostname"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "617aaa3557aef3810a6369d0a99fac8a080891b68bd9f9812a1eeda0c0730cbd"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "windows-link",
+]
+
 [[package]]
 name = "ident_case"
 version = "1.0.1"
@@ -930,6 +941,7 @@ name = "pilot-v2"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "hostname",
  "local-ip-address",
  "rumqttc",
  "serde",

pilot-v2/Cargo.toml

@@ -17,3 +17,4 @@ tokio = { version = "1", features = ["rt-multi-thread", "macros", "time", "signa
 sysinfo = "0.30"
 local-ip-address = "0.6"
 zbus = "3"
+hostname = "0.4"

pilot-v2/config.yaml

@@ -1,16 +1,16 @@
 # Codex created 2025-12-29_0224
 device:
-  name: pilot-device
+  name: $hostname
-  identifiers: ["pilot-device"]
+  identifiers: ["$hostname"]
 
 mqtt:
-  host: "127.0.0.1"
+  host: "10.0.0.3"
   port: 1883
   username: ""
   password: ""
   base_topic: "pilot"
   discovery_prefix: "homeassistant"
-  client_id: "pilot-device"
+  client_id: "$hostname"
   keepalive_s: 60
   qos: 0
   retain_states: true

pilot-v2/src/config/mod.rs

@@ -87,8 +87,12 @@ pub fn load() -> Result<Config> {
         if path.exists() {
             let raw = fs::read_to_string(&path)
                 .with_context(|| format!("failed reading config {}", path.display()))?;
-            let cfg: Config = serde_yaml::from_str(&raw)
+            let mut cfg: Config = serde_yaml::from_str(&raw)
                 .with_context(|| format!("failed parsing config {}", path.display()))?;
+
+            // Substituer $hostname par le vrai hostname
+            expand_variables(&mut cfg)?;
+
             validate(&cfg)?;
             return Ok(cfg);
         }
@@ -116,6 +120,39 @@ pub fn base_device_topic(cfg: &Config) -> String {
     format!("{}/{}", base, cfg.device.name)
 }
 
+// Obtient le hostname du système
+fn get_hostname() -> Result<String> {
+    let hostname = hostname::get()
+        .context("failed to get system hostname")?
+        .to_string_lossy()
+        .to_string();
+    Ok(hostname)
+}
+
+// Remplace les variables comme $hostname dans la config
+fn expand_variables(cfg: &mut Config) -> Result<()> {
+    let hostname = get_hostname()?;
+
+    // Remplacer dans device.name
+    if cfg.device.name == "$hostname" {
+        cfg.device.name = hostname.clone();
+    }
+
+    // Remplacer dans device.identifiers
+    for identifier in &mut cfg.device.identifiers {
+        if identifier == "$hostname" {
+            *identifier = hostname.clone();
+        }
+    }
+
+    // Remplacer dans client_id
+    if cfg.mqtt.client_id == "$hostname" {
+        cfg.mqtt.client_id = hostname.clone();
+    }
+
+    Ok(())
+}
+
 // Verifie les champs minimum pour eviter les erreurs au demarrage.
 fn validate(cfg: &Config) -> Result<()> {
     if cfg.device.name.trim().is_empty() {
@@ -180,4 +217,51 @@ publish:
         assert_eq!(cfg.mqtt.port, 1883);
         assert!(cfg.features.commands.dry_run);
     }
+
+    #[test]
+    fn hostname_substitution() {
+        let raw = r#"
+device:
+  name: "$hostname"
+  identifiers: ["$hostname"]
+mqtt:
+  host: "127.0.0.1"
+  port: 1883
+  username: ""
+  password: ""
+  base_topic: "pilot"
+  discovery_prefix: "homeassistant"
+  client_id: "$hostname"
+  keepalive_s: 60
+  qos: 0
+  retain_states: true
+features:
+  telemetry:
+    enabled: true
+    interval_s: 5
+  commands:
+    enabled: true
+    cooldown_s: 2
+    dry_run: true
+    allowlist: ["shutdown"]
+power_backend:
+  linux: "linux_logind_polkit"
+  windows: "windows_service"
+screen_backend:
+  linux: "gnome_busctl"
+  windows: "winapi_session"
+publish:
+  heartbeat_s: 10
+  availability: true
+"#;
+
+        let mut cfg: Config = serde_yaml::from_str(raw).unwrap();
+        expand_variables(&mut cfg).unwrap();
+
+        let hostname = get_hostname().unwrap();
+        assert_eq!(cfg.device.name, hostname);
+        assert_eq!(cfg.device.identifiers[0], hostname);
+        assert_eq!(cfg.mqtt.client_id, hostname);
+        assert_ne!(cfg.device.name, "$hostname");
+    }
 }

scripts/test_command.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+# Script simple pour tester les commandes MQTT avec Pilot v2
+# Usage: ./test_command.sh <action> <value>
+# Exemple: ./test_command.sh screen OFF
+
+MQTT_HOST="10.0.0.3"
+MQTT_PORT="1883"
+DEVICE="asus"
+
+if [ $# -ne 2 ]; then
+    echo "Usage: $0 <action> <value>"
+    echo "Actions: shutdown, reboot, sleep, screen"
+    echo "Values: ON, OFF"
+    echo "Exemple: $0 screen OFF"
+    exit 1
+fi
+
+ACTION=$1
+VALUE=$2
+TOPIC="pilot/${DEVICE}/cmd/${ACTION}/set"
+
+# Vérifier si mosquitto_pub est installé
+if ! command -v mosquitto_pub &> /dev/null; then
+    echo "❌ mosquitto_pub n'est pas installé"
+    echo "Installer avec: sudo apt install mosquitto-clients"
+    exit 1
+fi
+
+echo "📡 Envoi commande MQTT:"
+echo "   Topic: $TOPIC"
+echo "   Message: $VALUE"
+echo ""
+
+mosquitto_pub -h "$MQTT_HOST" -p "$MQTT_PORT" -t "$TOPIC" -m "$VALUE"
+
+if [ $? -eq 0 ]; then
+    echo "✅ Commande envoyée avec succès!"
+    echo ""
+    echo "Vérifiez les logs de Pilot pour voir le résultat:"
+    echo "   En dry-run mode, la commande sera loggée mais pas exécutée"
+else
+    echo "❌ Erreur lors de l'envoi de la commande"
+    exit 1
+fi