feat(config): hot-reload the configuration

Cargo.lock

@@ -652,6 +652,18 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "filetime"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "975ccf83d8d9d0d84682850a38c8169027be83368805971cc4f238c2b245bc98"
+dependencies = [
+ "cfg-if 1.0.0",
+ "libc",
+ "redox_syscall",
+ "winapi 0.3.9",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.20"
@@ -680,6 +692,25 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "fsevent"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ab7d1bd1bd33cc98b0889831b72da23c0aa4df9cec7e0702f46ecea04b35db6"
+dependencies = [
+ "bitflags",
+ "fsevent-sys",
+]
+
+[[package]]
+name = "fsevent-sys"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f41b048a94555da0f42f1d632e2e19510084fb8e303b0daa2816e733fb3644a0"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "fuchsia-zircon"
 version = "0.3.3"
@@ -880,6 +911,16 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "hotwatch"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39301670a6f5798b75f36a1b149a379a50df5aa7c71be50f4b41ec6eab445cb8"
+dependencies = [
+ "log",
+ "notify",
+]
+
 [[package]]
 name = "http"
 version = "0.2.4"
@@ -930,6 +971,26 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea70330449622910e0edebab230734569516269fb32342fb0a8956340fa48c6c"
 
+[[package]]
+name = "inotify"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4816c66d2c8ae673df83366c18341538f234a26d65a9ecea5c348b453ac1d02f"
+dependencies = [
+ "bitflags",
+ "inotify-sys",
+ "libc",
+]
+
+[[package]]
+name = "inotify-sys"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e05c02b5e89bff3b946cedeca278abc628fe811e604f027c45a8aa3cf793d0eb"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "instant"
 version = "0.1.10"
@@ -1029,6 +1090,12 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
+[[package]]
+name = "lazycell"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
+
 [[package]]
 name = "lexical-core"
 version = "0.7.6"
@@ -1144,6 +1211,18 @@ dependencies = [
  "winapi 0.2.8",
 ]
 
+[[package]]
+name = "mio-extras"
+version = "2.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52403fe290012ce777c4626790c8951324a2b9e3316b3143779c72b029742f19"
+dependencies = [
+ "lazycell",
+ "log",
+ "mio",
+ "slab",
+]
+
 [[package]]
 name = "mio-uds"
 version = "0.6.8"
@@ -1199,6 +1278,24 @@ dependencies = [
  "version_check 0.9.3",
 ]
 
+[[package]]
+name = "notify"
+version = "4.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae03c8c853dba7bfd23e571ff0cff7bc9dceb40a4cd684cd1681824183f45257"
+dependencies = [
+ "bitflags",
+ "filetime",
+ "fsevent",
+ "fsevent-sys",
+ "inotify",
+ "libc",
+ "mio",
+ "mio-extras",
+ "walkdir",
+ "winapi 0.3.9",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.13.0"
@@ -1549,6 +1646,7 @@ dependencies = [
  "env_logger",
  "futures-util",
  "glob",
+ "hotwatch",
  "humantime",
  "infer",
  "lazy-regex",
@@ -1569,6 +1667,15 @@ version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
 
+[[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 = "1.1.0"
@@ -2166,6 +2273,17 @@ version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
 
+[[package]]
+name = "walkdir"
+version = "2.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "808cf2735cd4b6866113f648b791c6adc5714537bc222d9347bb203386ffda56"
+dependencies = [
+ "same-file",
+ "winapi 0.3.9",
+ "winapi-util",
+]
+
 [[package]]
 name = "wasi"
 version = "0.9.0+wasi-snapshot-preview1"

Cargo.toml

@@ -31,6 +31,7 @@ lazy-regex = "2.2.1"
 humantime = "2.1.0"
 glob = "0.3.0"
 ring = "0.16.20"
+hotwatch = "0.4.5"
 
 [dependencies.config]
 version = "0.11.0"

README.md

@@ -14,7 +14,7 @@ some text
 
 ## Features
 
-- File upload & URL shortening
+- File upload & URL shortening & upload from URL
   - supports basic HTTP authentication
   - random file names (optional)
     - pet name (e.g. `capital-mosquito.txt`)
@@ -26,6 +26,8 @@ some text
   - no duplicate uploads (optional)
 - Single binary
   - [binary releases](https://github.com/orhun/rustypaste/releases)
+- Simple configuration
+  - supports hot reloading
 - Easy to deploy
   - [docker images](https://hub.docker.com/r/orhunp/rustypaste)
 - No database
@@ -184,7 +186,7 @@ http {
 
 ### Roadmap
 
-- Hot reload the configuration file
+_Nothing here yet! 🎉_
 
 ### Contributing
 

src/config.rs

@@ -2,7 +2,7 @@ use crate::mime::MimeMatcher;
 use crate::random::RandomURLConfig;
 use byte_unit::Byte;
 use config::{self, ConfigError};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 /// Configuration values.
 #[derive(Debug, Clone, Default, serde::Serialize, serde::Deserialize)]
@@ -43,10 +43,10 @@ pub struct PasteConfig {
 
 impl Config {
     /// Parses the config file and returns the values.
-    pub fn parse(file_name: &str) -> Result<Config, ConfigError> {
+    pub fn parse(path: &Path) -> Result<Config, ConfigError> {
         let mut config = config::Config::default();
         config
-            .merge(config::File::with_name(file_name))?
+            .merge(config::File::from(path))?
             .merge(config::Environment::new().separator("__"))?;
         config.try_into()
     }
@@ -59,13 +59,9 @@ mod tests {
 
     #[test]
     fn test_parse_config() -> Result<(), ConfigError> {
-        let file_name = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        let config_path = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("config.toml");
-            .join("config.toml")
-            .to_str()
-            .unwrap()
-            .to_string();
         env::set_var("SERVER__ADDRESS", "0.0.1.1");
-        let config = Config::parse(&file_name)?;
+        let config = Config::parse(&config_path)?;
         assert_eq!("0.0.1.1", config.server.address);
         Ok(())
     }

src/main.rs

@@ -1,39 +1,78 @@
 use actix_web::client::ClientBuilder;
 use actix_web::middleware::Logger;
 use actix_web::{App, HttpServer};
+use hotwatch::{Event, Hotwatch};
 use rustypaste::config::Config;
 use rustypaste::paste::PasteType;
 use rustypaste::server;
 use std::env;
 use std::fs;
 use std::io::Result as IoResult;
+use std::path::PathBuf;
+use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
 #[actix_web::main]
 async fn main() -> IoResult<()> {
-    dotenv::dotenv().ok();
+    // Initialize logger.
     env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
-    let config = Config::parse(env::var("CONFIG").as_deref().unwrap_or("config"))
+
-        .expect("failed to parse config");
+    // Parse configuration.
-    let server_config = config.server.clone();
+    dotenv::dotenv().ok();
+    let config_path =
+        PathBuf::from(env::var("CONFIG").unwrap_or_else(|_| String::from("config.toml")));
+    let config = Arc::new(Mutex::new(
+        Config::parse(&config_path).expect("failed to parse config"),
+    ));
+    let cloned_config = Arc::clone(&config);
+    let server_config = config.lock().expect("cannot acquire config").server.clone();
+
+    // Create necessary directories.
     fs::create_dir_all(&server_config.upload_path)?;
     for paste_type in &[PasteType::Url, PasteType::Oneshot] {
         fs::create_dir_all(paste_type.get_path(&server_config.upload_path))?;
     }
+
+    // Set up a watcher for the configuration file changes.
+    let mut hotwatch = Hotwatch::new_with_custom_delay(Duration::from_secs(1))
+        .expect("failed to initialize configuration file watcher");
+
+    // Hot-reload the configuration file.
+    hotwatch
+        .watch(&config_path, move |event: Event| {
+            if let Event::Write(path) = event {
+                match Config::parse(&path) {
+                    Ok(config) => {
+                        *cloned_config.lock().expect("cannot acquire config") = config;
+                        log::info!("Configuration has been updated.");
+                    }
+                    Err(e) => {
+                        log::error!("Failed to update configuration: {}", e);
+                    }
+                }
+            }
+        })
+        .unwrap_or_else(|_| panic!("failed to watch {:?}", config_path));
+
+    // Create a HTTP server.
     let mut http_server = HttpServer::new(move || {
         let http_client = ClientBuilder::default()
             .timeout(Duration::from_secs(30))
             .disable_redirects()
             .finish();
         App::new()
-            .data(config.clone())
+            .data(Arc::clone(&config))
             .data(http_client)
             .wrap(Logger::default())
             .configure(server::configure_routes)
     })
     .bind(server_config.address)?;
+
+    // Set worker count for the server.
     if let Some(workers) = server_config.workers {
         http_server = http_server.workers(workers);
     }
+
+    // Run the server.
     http_server.run().await
 }

src/server.rs

@@ -14,6 +14,7 @@ use futures_util::stream::StreamExt;
 use std::convert::TryFrom;
 use std::env;
 use std::fs;
+use std::sync::{Arc, Mutex};
 
 /// Shows the landing page.
 #[get("/")]
@@ -81,13 +82,14 @@ async fn upload(
     request: HttpRequest,
     mut payload: Multipart,
     client: web::Data<Client>,
-    config: web::Data<Config>,
+    config: web::Data<Arc<Mutex<Config>>>,
 ) -> Result<HttpResponse, Error> {
     let connection = request.connection_info();
     let host = connection.remote_addr().unwrap_or("unknown host");
     auth::check(host, request.headers(), env::var("AUTH_TOKEN").ok())?;
     let expiry_date = header::parse_expiry_date(request.headers())?;
     let mut urls: Vec<String> = Vec::new();
+    let config = config.lock().expect("cannot acquire config");
     while let Some(item) = payload.next().await {
         let mut field = item?;
         let content = ContentDisposition::try_from(field.content_disposition())?;
@@ -96,7 +98,7 @@ async fn upload(
             while let Some(chunk) = field.next().await {
                 bytes.append(&mut chunk?.to_vec());
                 if bytes.len() as u128 > config.server.max_content_length.get_bytes() {
-                    log::warn!("upload rejected for {}", host);
+                    log::warn!("Upload rejected for {}", host);
                     return Err(error::ErrorPayloadTooLarge("upload limit exceeded"));
                 }
             }