Add bind arg and better error handling

2 files changed, 31 insertions, 3 deletions

diff --git a/README.md b/README.md
index e598e7d..7d463a3 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,27 @@ Or directly:
 cargo run
 ```
 
-The server listens on `0.0.0.0:3000`.
+By default the server listens on `0.0.0.0:3000` and reads config from `config.toml`.
+
+## CLI Arguments
+
+| Argument | Default | Description |
+|----------|---------|-------------|
+| `--config <PATH>` | `config.toml` | Path to the configuration file |
+| `--bind <ADDR>` | `0.0.0.0:3000` | Address to bind the HTTP server to |
+
+Examples:
+
+```sh
+# Use a custom config file
+./target/release/printstats --config /etc/printstats/config.toml
+
+# Listen on a different address/port
+./target/release/printstats --bind 127.0.0.1:8080
+
+# Both at once
+./target/release/printstats --config /etc/printstats/config.toml --bind 127.0.0.1:8080
+```
 
 ## API
 
diff --git a/src/main.rs b/src/main.rs
index 187c0fe..5337fc3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -19,6 +19,10 @@ struct Args {
     /// Path to the configuration file
     #[arg(long, default_value = "config.toml")]
     config: String,
+
+    /// Address to bind the HTTP server to
+    #[arg(long, default_value = "0.0.0.0:3000")]
+    bind: String,
 }
 
 #[tokio::main]
@@ -26,7 +30,8 @@ async fn main() {
     tracing_subscriber::fmt::init();
 
     let args = Args::parse();
-    let content = fs::read_to_string(&args.config).expect("Couldn't read config file");
+    let content = fs::read_to_string(&args.config)
+        .unwrap_or_else(|e| panic!("Failed to read '{}': {}", args.config, e));
     let config = Config::load(&content);
     let state: StateMap = Arc::new(Mutex::new(HashMap::new()));
     let mut tasks = JoinSet::new();
@@ -80,7 +85,10 @@ async fn main() {
 
     let app = Router::new().route("/", get(root)).with_state(state);
 
-    let listener = tokio::net::TcpListener::bind("0.0.0.0:3000").await.unwrap();
+    let listener = tokio::net::TcpListener::bind(&args.bind)
+        .await
+        .unwrap_or_else(|e| panic!("Failed to bind to '{}': {}", args.bind, e));
+    println!("Listening on {}", args.bind);
     axum::serve(listener, app).await.unwrap();
 }