feat: detect file changes

Cargo.lock

@@ -190,7 +190,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -199,6 +199,15 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77ce24cb58228fbb8aa041425bb1050850ac19177686ea6e0f41a70416f56fdb"
 
+[[package]]
+name = "fsevent-sys"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76ee7a02da4d231650c7cea31349b889be2f45ddb3ef3032d2ec8185f6313fd2"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "generic-array"
 version = "0.14.7"
@@ -244,6 +253,26 @@ dependencies = [
  "hashbrown 0.16.1",
 ]
 
+[[package]]
+name = "inotify"
+version = "0.11.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd854a95a4ac672fed8c054136039fd32c22cf039ff09ead7280afe920486483"
+dependencies = [
+ "bitflags",
+ "inotify-sys",
+ "libc",
+]
+
+[[package]]
+name = "inotify-sys"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c033f80b2c113cdf91ab7a33faa9cbc014726dcad99880c8609af2a370edf37d"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.18"
@@ -261,6 +290,26 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "kqueue"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "273c0752728918e0ac4976f2b275b6fefb9ecd400585dec929419f3844cd87b5"
+dependencies = [
+ "kqueue-sys",
+ "libc",
+]
+
+[[package]]
+name = "kqueue-sys"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "07293a4e297ac234359b510362495713f75ea345d5307140414f20c69ffeb087"
+dependencies = [
+ "bitflags",
+ "libc",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.5.0"
@@ -310,8 +359,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "02bd0af71c67b473010cbbc60715ee815645a4dc942899111f494b4b737d6fda"
 dependencies = [
  "libc",
+ "log",
  "wasi",
- "windows-sys",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -321,19 +371,47 @@ dependencies = [
  "anyhow",
  "config",
  "dotenv",
+ "notify",
  "serde",
  "tokio",
  "tracing",
  "tracing-subscriber",
 ]
 
+[[package]]
+name = "notify"
+version = "8.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4d3d07927151ff8575b7087f245456e549fea62edf0ec4e565a5ee50c8402bc3"
+dependencies = [
+ "bitflags",
+ "fsevent-sys",
+ "inotify",
+ "kqueue",
+ "libc",
+ "log",
+ "mio",
+ "notify-types",
+ "walkdir",
+ "windows-sys 0.60.2",
+]
+
+[[package]]
+name = "notify-types"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42b8cfee0e339a0337359f3c88165702ac6e600dc01c0cc9579a92d62b08477a"
+dependencies = [
+ "bitflags",
+]
+
 [[package]]
 name = "nu-ansi-term"
 version = "0.50.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7957b9740744892f114936ab4a57b3f487491bbeafaf8083688b16841a4240e5"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -498,6 +576,15 @@ dependencies = [
  "ordered-multimap",
 ]
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.2.0"
@@ -611,7 +698,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "52d1cfed4120b4d927bf7c0f86d2087a4a7d6027c906d9f9d525a80573b9be51"
 dependencies = [
  "libc",
- "windows-sys",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -657,7 +744,7 @@ dependencies = [
  "signal-hook-registry",
  "socket2",
  "tokio-macros",
- "windows-sys",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -805,18 +892,46 @@ version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "wasi"
 version = "0.11.1+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "windows-link"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
+[[package]]
+name = "windows-sys"
+version = "0.60.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.61.2"
@@ -826,6 +941,71 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "windows-targets"
+version = "0.53.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
+dependencies = [
+ "windows-link",
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
+
 [[package]]
 name = "winnow"
 version = "1.0.3"

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2024"
 anyhow = "1.0.103"
 config = "0.15.25"
 dotenv = "0.15.0"
+notify = "8.2.0"
 serde = { version = "1.0.228", features = ["derive"] }
 tokio = { version = "1.52.3", features = ["full"] }
 tracing = "0.1.44"

src/config.rs

@@ -1,9 +1,13 @@
+use std::{path::Path, sync::Arc, time::Duration};
+
 use anyhow::{Result, ensure};
+use notify::{EventKind, INotifyWatcher, Watcher};
 use serde::Deserialize;
+use tokio::sync::{RwLock, mpsc};
 
 #[derive(Deserialize)]
 #[allow(clippy::upper_case_acronyms)]
-pub enum EntryType {
+pub enum RecordType {
     A,
     AAAA,
     MX,
@@ -12,7 +16,7 @@ pub enum EntryType {
 #[derive(Deserialize)]
 pub struct Entry {
     #[serde(rename = "type")]
-    pub entry_type: EntryType,
+    pub rtype: RecordType,
     pub name: String,
     pub address: String,
     #[serde(skip)]
@@ -77,3 +81,51 @@ pub fn load() -> Result<ConfigData> {
         entries: file_config.entries,
     })
 }
+
+pub fn watch(config: Arc<RwLock<ConfigData>>) -> Result<INotifyWatcher> {
+    let (tx, mut rx) = mpsc::channel(100);
+    let mut watcher = notify::recommended_watcher(move |event| {
+        let _ = tx.blocking_send(event);
+    })?;
+    watcher.configure(notify::Config::default().with_poll_interval(Duration::from_secs(10)))?;
+    watcher.watch(
+        Path::new("nanodns.toml"),
+        notify::RecursiveMode::NonRecursive,
+    )?;
+
+    tokio::spawn(async move {
+        loop {
+            let Some(event) = rx.recv().await else {
+                tracing::info!("watch channel closed");
+                break;
+            };
+
+            match event {
+                Ok(event) => {
+                    if let EventKind::Modify(_) = event.kind {
+                        let new_config = match load() {
+                            Ok(new_config) => new_config,
+                            Err(err) => {
+                                tracing::error!("Failed to load new config: {err}");
+                                break;
+                            }
+                        };
+
+                        tracing::info!("Detected config change");
+                        {
+                            let mut config = config.write().await;
+                            *config = new_config;
+                        }
+                        tracing::info!("Config change applied");
+                    }
+                }
+                Err(err) => {
+                    tracing::error!("error in watch channel: {err}");
+                    break;
+                }
+            }
+        }
+    });
+
+    Ok(watcher)
+}

src/main.rs

@@ -10,11 +10,11 @@ mod ext;
 mod logging;
 mod macros;
 
-use std::{io::Cursor, net::SocketAddr};
+use std::{io::Cursor, net::SocketAddr, sync::Arc};
 
 use anyhow::Result;
 use dotenv::dotenv;
-use tokio::net::UdpSocket;
+use tokio::{net::UdpSocket, sync::RwLock};
 use tracing::{Instrument, Level};
 
 use crate::{
@@ -27,15 +27,18 @@ async fn main() -> Result<()> {
     dotenv().ok();
     logging::setup();
     let config = config::load()?;
+    let port = config.port;
+    let config = Arc::new(RwLock::new(config));
+    let _watcher = config::watch(config.clone())?;
 
-    tracing::info!("start server on port {}", config.port);
+    tracing::info!("start server on port {}", port);
-    let sock = UdpSocket::bind(("0.0.0.0", config.port)).await?;
+    let sock = UdpSocket::bind(("0.0.0.0", port)).await?;
     let mut buffer = [0u8; 512];
 
     loop {
         let (size, addr) = sock.recv_from(&mut buffer).await?;
         let mut cursor = Cursor::new(&buffer[..size]);
-        let result = handle_datagram(&config, &sock, &addr, &mut cursor).await;
+        let result = handle_datagram(config.clone(), &sock, &addr, &mut cursor).await;
         if let Err(err) = result {
             tracing::error!("failed to handle datagram: {err}");
         }
@@ -43,7 +46,7 @@ async fn main() -> Result<()> {
 }
 
 async fn handle_datagram(
-    config: &config::ConfigData,
+    config: Arc<RwLock<config::ConfigData>>,
     sock: &UdpSocket,
     addr: &SocketAddr,
     cursor: &mut Cursor<&[u8]>,
@@ -80,7 +83,7 @@ async fn handle_datagram(
 
             match question.qtype {
                 RECORD_TYPE_A => {
-                    handle_type_a_question(config, &question, &mut response);
+                    handle_type_a_question(config.clone(), &question, &mut response).await;
                 }
                 qt => {
                     tracing::error!("unsupported question type, requested: {qt}");
@@ -100,8 +103,15 @@ async fn handle_datagram(
     result
 }
 
-fn handle_type_a_question(config: &ConfigData, question: &Question, response: &mut Message) {
+async fn handle_type_a_question(
-    let address = config.get_ipv4_address_by_domain(&question.domain);
+    config: Arc<RwLock<ConfigData>>,
+    question: &Question,
+    response: &mut Message,
+) {
+    let address = {
+        let config = config.read().await;
+        config.get_ipv4_address_by_domain(&question.domain)
+    };
     match address {
         Some(address) => {
             let answer = Answer {