feat: move rss to it's own module and add atom support

Cargo.lock

@@ -906,6 +906,21 @@ dependencies = [
  "tracing-subscriber",
 ]
 
+[[package]]
+name = "noisebell-rss"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "axum",
+ "chrono",
+ "noisebell-common",
+ "reqwest",
+ "tokio",
+ "tower-http",
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "nu-ansi-term"
 version = "0.50.3"

Cargo.toml

@@ -3,6 +3,17 @@ members = [
     "pi/pi-service",
     "remote/noisebell-common",
     "remote/cache-service",
+    "remote/rss-service",
     "remote/discord-bot",
 ]
 resolver = "2"
+
+[workspace.lints.rust]
+unsafe_code = "forbid"
+
+[workspace.lints.clippy]
+dbg_macro = "warn"
+print_stderr = "warn"
+print_stdout = "warn"
+todo = "warn"
+unimplemented = "warn"

flake.nix

@@ -66,6 +66,7 @@
         );
 
       noisebell-cache = buildRemoteMember "noisebell-cache";
+      noisebell-rss = buildRemoteMember "noisebell-rss";
       noisebell-discord = buildRemoteMember "noisebell-discord";
 
       crossPkgs = import nixpkgs {
@@ -346,6 +347,7 @@
       packages.${system} = {
         inherit
           noisebell-cache
+          noisebell-rss
           noisebell-discord
           flash-pi-sd
           pi-serial
@@ -361,10 +363,12 @@
 
       nixosModules = {
         cache = import ./remote/cache-service/module.nix noisebell-cache;
+        rss = import ./remote/rss-service/module.nix noisebell-rss;
         discord = import ./remote/discord-bot/module.nix noisebell-discord;
         default = {
           imports = [
             (import ./remote/cache-service/module.nix noisebell-cache)
+            (import ./remote/rss-service/module.nix noisebell-rss)
             (import ./remote/discord-bot/module.nix noisebell-discord)
             (import ./remote/hosted-module.nix {
               inherit self agenix;

pi/pi-service/Cargo.toml

@@ -3,6 +3,9 @@ name = "noisebell"
 version = "0.1.0"
 edition = "2021"
 
+[lints]
+workspace = true
+
 [dependencies]
 anyhow = "1.0"
 axum = "0.8"

pi/pi-service/src/main.rs

@@ -1,4 +1,4 @@
-use std::sync::atomic::{AtomicU8, AtomicU64, Ordering};
+use std::sync::atomic::{AtomicU64, AtomicU8, Ordering};
 use std::sync::Arc;
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
@@ -42,7 +42,6 @@ impl LocalDoorState {
             Self::Closed => DoorStatus::Closed,
         }
     }
-
 }
 
 struct AppState {
@@ -58,10 +57,7 @@ impl AppState {
 }
 
 fn unix_timestamp() -> u64 {
-    SystemTime::now()
-        .duration_since(UNIX_EPOCH)
-        .unwrap()
-        .as_secs()
+    SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_secs()
 }
 
 async fn get_status(
@@ -124,11 +120,7 @@ async fn main() -> Result<()> {
         .unwrap_or_else(|_| "true".into())
         .parse()
         .context("NOISEBELL_ACTIVE_LOW must be true or false")?;
-    let active_level = if active_low {
-        SignalLevel::Low
-    } else {
-        SignalLevel::High
-    };
+    let active_level = if active_low { SignalLevel::Low } else { SignalLevel::High };
 
     let inbound_api_key = std::env::var("NOISEBELL_INBOUND_API_KEY")
         .context("NOISEBELL_INBOUND_API_KEY is required")?;
@@ -137,33 +129,20 @@ async fn main() -> Result<()> {
 
     let chip = Chip::new("gpiochip0").context("failed to open gpiochip0")?;
 
-    let bias = if active_level == SignalLevel::Low {
-        Bias::PullUp
-    } else {
-        Bias::PullDown
-    };
+    let bias = if active_level == SignalLevel::Low { Bias::PullUp } else { Bias::PullDown };
 
     // Keep the line requested and poll its value. Edge-triggered reads have
     // proven unreliable on Raspberry Pi OS even though the raw line level is
     // correct, so we debounce from sampled levels instead.
-    let opts = Options::input([gpio_pin])
-        .bias(bias)
-        .consumer("noisebell");
-    let inputs = chip
-        .request_lines(opts)
-        .context(format!("failed to request GPIO line {gpio_pin}"))?;
+    let opts = Options::input([gpio_pin]).bias(bias).consumer("noisebell");
+    let inputs =
+        chip.request_lines(opts).context(format!("failed to request GPIO line {gpio_pin}"))?;
 
     // Read initial value
-    let initial_values = inputs
-        .get_values([false])
-        .context("failed to read initial GPIO value")?;
+    let initial_values = inputs.get_values([false]).context("failed to read initial GPIO value")?;
     // Value is true when line is active. With Active::High (default),
     // true means the physical level is high.
-    let initial_raw_level = if initial_values[0] {
-        SignalLevel::High
-    } else {
-        SignalLevel::Low
-    };
+    let initial_raw_level = if initial_values[0] { SignalLevel::High } else { SignalLevel::Low };
     let initial_state = LocalDoorState::from_raw_level(initial_raw_level, active_level);
 
     let now = unix_timestamp();
@@ -205,11 +184,7 @@ async fn main() -> Result<()> {
                 }
             };
 
-            let new_raw_level = if values[0] {
-                SignalLevel::High
-            } else {
-                SignalLevel::Low
-            };
+            let new_raw_level = if values[0] { SignalLevel::High } else { SignalLevel::Low };
             let new_state = LocalDoorState::from_raw_level(new_raw_level, active_level);
 
             if new_state != pending_state {
@@ -218,9 +193,7 @@ async fn main() -> Result<()> {
             } else if new_state != current_state && pending_since.elapsed() >= debounce {
                 current_state = new_state;
                 let previous_state = LocalDoorState::from_atomic(
-                    state_for_edges
-                        .door_state
-                        .swap(new_state as u8, Ordering::Relaxed),
+                    state_for_edges.door_state.swap(new_state as u8, Ordering::Relaxed),
                 );
 
                 if previous_state == new_state {
@@ -229,9 +202,7 @@ async fn main() -> Result<()> {
                 }
 
                 let timestamp = unix_timestamp();
-                state_for_edges
-                    .last_changed
-                    .store(timestamp, Ordering::Relaxed);
+                state_for_edges.last_changed.store(timestamp, Ordering::Relaxed);
                 let _ = edge_tx.send((new_state.as_door_status(), timestamp));
             }
 
@@ -252,12 +223,8 @@ async fn main() -> Result<()> {
             let payload = WebhookPayload { status, timestamp };
 
             for attempt in 0..=retry_attempts {
-                let result = client
-                    .post(&endpoint_url)
-                    .bearer_auth(&api_key)
-                    .json(&payload)
-                    .send()
-                    .await;
+                let result =
+                    client.post(&endpoint_url).bearer_auth(&api_key).json(&payload).send().await;
                 match result {
                     Ok(resp) if resp.status().is_success() => break,
                     _ => {
@@ -279,9 +246,7 @@ async fn main() -> Result<()> {
         }
     });
 
-    let app = Router::new()
-        .route("/", get(get_status))
-        .with_state(state);
+    let app = Router::new().route("/", get(get_status)).with_state(state);
 
     let listener = tokio::net::TcpListener::bind((&*bind_address, port))
         .await

remote/README.md

@@ -5,6 +5,7 @@ Cargo workspace with the server-side pieces of Noisebell. Runs on any Linux box.
 | Service | Port | What it does |
 |---------|------|--------------|
 | [`cache-service/`](cache-service/) | 3000 | Polls the Pi, stores the latest state in SQLite, fans out webhooks |
+| [`rss-service/`](rss-service/) | 3002 | Fetches current status from cache and serves RSS/Atom feeds |
 | [`discord-bot/`](discord-bot/) | 3001 | Posts door status to a Discord channel |
 | [`noisebell-common/`](noisebell-common/) | — | Shared types and helpers |
 
@@ -20,6 +21,7 @@ Or with Nix:
 
 ```sh
 nix build .#noisebell-cache
+nix build .#noisebell-rss
 nix build .#noisebell-discord
 ```
 
@@ -42,6 +44,10 @@ The flake exports a NixOS module for the hosted remote machine. It imports `agen
             domain = "cache.noisebell.example.com";
             piAddress = "http://noisebell-pi:80";
           };
+          services.noisebell-rss = {
+            enable = true;
+            domain = "rss.noisebell.example.com";
+          };
           services.noisebell-discord = {
             enable = true;
             domain = "discord.noisebell.example.com";

remote/cache-service/Cargo.toml

@@ -3,6 +3,9 @@ name = "noisebell-cache"
 version = "0.1.0"
 edition = "2021"
 
+[lints]
+workspace = true
+
 [dependencies]
 anyhow = "1.0"
 axum = "0.8"

remote/cache-service/src/api.rs

@@ -30,10 +30,7 @@ pub struct AppState {
 }
 
 fn unix_now() -> u64 {
-    std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .unwrap()
-        .as_secs()
+    std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_secs()
 }
 
 fn format_full_timestamp(ts: u64) -> String {
@@ -43,12 +40,7 @@ fn format_full_timestamp(ts: u64) -> String {
 }
 
 fn format_duration(seconds: u64) -> String {
-    let units = [
-        (86_400, "day"),
-        (3_600, "hour"),
-        (60, "minute"),
-        (1, "second"),
-    ];
+    let units = [(86_400, "day"), (3_600, "hour"), (60, "minute"), (1, "second")];
 
     let mut remaining = seconds;
     let mut parts = Vec::new();
@@ -75,7 +67,12 @@ fn format_duration(seconds: u64) -> String {
     }
 }
 
-fn status_summary(status: DoorStatus, since: Option<u64>, last_checked: Option<u64>, now: u64) -> String {
+fn status_summary(
+    status: DoorStatus,
+    since: Option<u64>,
+    last_checked: Option<u64>,
+    now: u64,
+) -> String {
     let since_text = since
         .map(|ts| {
             format!(
@@ -111,16 +108,10 @@ pub async fn post_webhook(
 
     // Simple rate limiting: reset tokens every window, reject if exhausted.
     let now = unix_now();
-    let last = state
-        .webhook_last_request
-        .load(std::sync::atomic::Ordering::Relaxed);
+    let last = state.webhook_last_request.load(std::sync::atomic::Ordering::Relaxed);
     if now.saturating_sub(last) >= WEBHOOK_RATE_WINDOW_SECS {
-        state
-            .webhook_tokens
-            .store(WEBHOOK_RATE_LIMIT, std::sync::atomic::Ordering::Relaxed);
-        state
-            .webhook_last_request
-            .store(now, std::sync::atomic::Ordering::Relaxed);
+        state.webhook_tokens.store(WEBHOOK_RATE_LIMIT, std::sync::atomic::Ordering::Relaxed);
+        state.webhook_last_request.store(now, std::sync::atomic::Ordering::Relaxed);
     }
     let remaining = state.webhook_tokens.fetch_update(
         std::sync::atomic::Ordering::Relaxed,
@@ -153,10 +144,7 @@ pub async fn post_webhook(
             webhook::forward(
                 &state.client,
                 &state.webhooks,
-                &WebhookPayload {
-                    status,
-                    timestamp: body.timestamp,
-                },
+                &WebhookPayload { status, timestamp: body.timestamp },
                 state.retry_attempts,
                 state.retry_base_delay_secs,
             )
@@ -200,7 +188,8 @@ pub async fn get_status(
         StatusCode::INTERNAL_SERVER_ERROR
     })?;
 
-    status.human_readable = status_summary(status.status, status.since, status.last_checked, unix_now());
+    status.human_readable =
+        status_summary(status.status, status.since, status.last_checked, unix_now());
 
     Ok(Json(status))
 }
@@ -211,30 +200,21 @@ pub async fn health() -> StatusCode {
 
 pub async fn get_image_open() -> impl IntoResponse {
     (
-        [
-            (header::CONTENT_TYPE, "image/png"),
-            (header::CACHE_CONTROL, "public, max-age=86400"),
-        ],
+        [(header::CONTENT_TYPE, "image/png"), (header::CACHE_CONTROL, "public, max-age=86400")],
         OPEN_PNG,
     )
 }
 
 pub async fn get_image_closed() -> impl IntoResponse {
     (
-        [
-            (header::CONTENT_TYPE, "image/png"),
-            (header::CACHE_CONTROL, "public, max-age=86400"),
-        ],
+        [(header::CONTENT_TYPE, "image/png"), (header::CACHE_CONTROL, "public, max-age=86400")],
         CLOSED_PNG,
     )
 }
 
 pub async fn get_image_offline() -> impl IntoResponse {
     (
-        [
-            (header::CONTENT_TYPE, "image/png"),
-            (header::CACHE_CONTROL, "public, max-age=86400"),
-        ],
+        [(header::CONTENT_TYPE, "image/png"), (header::CACHE_CONTROL, "public, max-age=86400")],
         OFFLINE_PNG,
     )
 }
@@ -260,13 +240,7 @@ pub async fn get_image(State(state): State<Arc<AppState>>) -> Response {
         DoorStatus::Closed => CLOSED_PNG,
         DoorStatus::Offline => OFFLINE_PNG,
     };
-    (
-        [
-            (header::CONTENT_TYPE, "image/png"),
-            (header::CACHE_CONTROL, "public, max-age=5"),
-        ],
-        image,
-    )
+    ([(header::CONTENT_TYPE, "image/png"), (header::CACHE_CONTROL, "public, max-age=5")], image)
         .into_response()
 }
 

remote/cache-service/src/db.rs

@@ -1,6 +1,3 @@
-use std::path::Path;
-use std::time::{SystemTime, UNIX_EPOCH};
-
 use anyhow::{Context, Result};
 use noisebell_common::{CacheStatusResponse, DoorStatus};
 use rusqlite::{Connection, OptionalExtension};
@@ -63,9 +60,7 @@ struct CurrentStateRow {
 }
 
 fn parse_status(status: &str, location: &str) -> Result<DoorStatus> {
-    status
-        .parse()
-        .with_context(|| format!("invalid door status {status:?} in {location}"))
+    status.parse().with_context(|| format!("invalid door status {status:?} in {location}"))
 }
 
 pub fn init(path: &str) -> Result<Connection> {
@@ -103,18 +98,12 @@ fn current_state_has_column(conn: &Connection, column: &str) -> Result<bool> {
 
 fn migrate_current_state(conn: &Connection) -> Result<()> {
     if !current_state_has_column(conn, "last_checked")? {
-        conn.execute(
-            "ALTER TABLE current_state ADD COLUMN last_checked INTEGER",
-            [],
-        )
-        .context("failed to add current_state.last_checked")?;
+        conn.execute("ALTER TABLE current_state ADD COLUMN last_checked INTEGER", [])
+            .context("failed to add current_state.last_checked")?;
     }
 
-    conn.execute(
-        "UPDATE current_state SET status = 'offline' WHERE status IS NULL",
-        [],
-    )
-    .context("failed to backfill NULL current_state.status")?;
+    conn.execute("UPDATE current_state SET status = 'offline' WHERE status IS NULL", [])
+        .context("failed to backfill NULL current_state.status")?;
 
     validate_status_values(conn)?;
     Ok(())
@@ -168,14 +157,12 @@ fn current_state_row(conn: &Connection) -> Result<CurrentStateRow> {
     let status = parse_status(&status_str, "current_state.status")?;
 
     let state = match (status, since) {
-        (DoorStatus::Open, Some(since)) => CachedState::Live {
-            status: LiveDoorStatus::Open,
-            since,
-        },
-        (DoorStatus::Closed, Some(since)) => CachedState::Live {
-            status: LiveDoorStatus::Closed,
-            since,
-        },
+        (DoorStatus::Open, Some(since)) => {
+            CachedState::Live { status: LiveDoorStatus::Open, since }
+        }
+        (DoorStatus::Closed, Some(since)) => {
+            CachedState::Live { status: LiveDoorStatus::Closed, since }
+        }
         (DoorStatus::Offline, Some(since)) => CachedState::Offline { since },
         (DoorStatus::Offline, None) => CachedState::Unknown,
         (DoorStatus::Open | DoorStatus::Closed, None) => {
@@ -183,11 +170,7 @@ fn current_state_row(conn: &Connection) -> Result<CurrentStateRow> {
         }
     };
 
-    Ok(CurrentStateRow {
-        state,
-        last_seen,
-        last_checked,
-    })
+    Ok(CurrentStateRow { state, last_seen, last_checked })
 }
 
 pub fn get_status(conn: &Connection) -> Result<CacheStatusResponse> {
@@ -228,10 +211,11 @@ pub fn apply_state(
         CachedState::Offline { since } if timestamp < since => ApplyStateOutcome::Stale,
         CachedState::Offline { .. } => ApplyStateOutcome::Applied,
         CachedState::Live { status: _, since } if timestamp < since => ApplyStateOutcome::Stale,
-        CachedState::Live {
-            status: current_status,
-            since,
-        } if timestamp == since && live_status == current_status => ApplyStateOutcome::Duplicate,
+        CachedState::Live { status: current_status, since }
+            if timestamp == since && live_status == current_status =>
+        {
+            ApplyStateOutcome::Duplicate
+        }
         CachedState::Live { .. } => ApplyStateOutcome::Applied,
     };
 
@@ -244,10 +228,7 @@ pub fn apply_state(
 }
 
 pub fn update_last_seen(conn: &Connection, now: u64) -> Result<()> {
-    conn.execute(
-        "UPDATE current_state SET last_seen = ?1 WHERE id = 1",
-        rusqlite::params![now],
-    )?;
+    conn.execute("UPDATE current_state SET last_seen = ?1 WHERE id = 1", rusqlite::params![now])?;
     Ok(())
 }
 
@@ -275,16 +256,15 @@ pub fn get_current_status(conn: &Connection) -> Result<DoorStatus> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::path::Path;
+    use std::time::{SystemTime, UNIX_EPOCH};
 
     fn test_db() -> Connection {
         init(":memory:").expect("failed to init test db")
     }
 
     fn temp_db_path(label: &str) -> std::path::PathBuf {
-        let nanos = SystemTime::now()
-            .duration_since(UNIX_EPOCH)
-            .unwrap()
-            .as_nanos();
+        let nanos = SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_nanos();
         std::env::temp_dir().join(format!("noisebell-{label}-{nanos}.sqlite"))
     }
 
@@ -464,11 +444,7 @@ mod tests {
         create_legacy_db(&path);
 
         let conn = Connection::open(&path).unwrap();
-        conn.execute(
-            "UPDATE current_state SET status = 'mystery' WHERE id = 1",
-            [],
-        )
-        .unwrap();
+        conn.execute("UPDATE current_state SET status = 'mystery' WHERE id = 1", []).unwrap();
         drop(conn);
 
         let err = init(path.to_str().unwrap()).unwrap_err().to_string();

remote/cache-service/src/poller.rs

@@ -21,10 +21,7 @@ pub struct PollerConfig {
 }
 
 fn unix_now() -> u64 {
-    std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .unwrap()
-        .as_secs()
+    std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_secs()
 }
 
 pub fn spawn_status_poller(
@@ -168,10 +165,7 @@ pub fn spawn_status_poller(
                                 webhook::forward(
                                     &client,
                                     &config.webhooks,
-                                    &WebhookPayload {
-                                        status: DoorStatus::Offline,
-                                        timestamp: now,
-                                    },
+                                    &WebhookPayload { status: DoorStatus::Offline, timestamp: now },
                                     config.retry_attempts,
                                     config.retry_base_delay_secs,
                                 )

remote/discord-bot/Cargo.toml

@@ -3,6 +3,9 @@ name = "noisebell-discord"
 version = "0.1.0"
 edition = "2021"
 
+[lints]
+workspace = true
+
 [dependencies]
 anyhow = "1.0"
 axum = "0.8"

remote/discord-bot/src/main.rs

@@ -87,10 +87,7 @@ async fn post_webhook(
 }
 
 fn unix_now() -> u64 {
-    std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .unwrap()
-        .as_secs()
+    std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_secs()
 }
 
 fn format_timestamp(ts: u64) -> String {
@@ -106,11 +103,9 @@ async fn handle_status(
 
     let embed = match resp {
         Ok(resp) if resp.status().is_success() => match resp.json::<CacheStatusResponse>().await {
-            Ok(data) => build_embed(
-                data.status,
-                data.since.unwrap_or(unix_now()),
-                &state.image_base_url,
-            ),
+            Ok(data) => {
+                build_embed(data.status, data.since.unwrap_or(unix_now()), &state.image_base_url)
+            }
             Err(e) => {
                 error!(error = %e, "failed to parse status response");
                 CreateEmbed::new()
@@ -137,7 +132,8 @@ impl serenity::all::EventHandler for Handler {
     async fn ready(&self, ctx: serenity::all::Context, ready: serenity::model::gateway::Ready) {
         info!(user = %ready.user.name, "Discord bot connected");
 
-        let commands = vec![CreateCommand::new("status").description("Show the current door status")];
+        let commands =
+            vec![CreateCommand::new("status").description("Show the current door status")];
 
         if let Err(e) = serenity::all::Command::set_global_commands(&ctx.http, commands).await {
             error!(error = %e, "failed to register slash commands");

remote/hosted-module.nix

@@ -3,6 +3,7 @@
 
 let
   cfgCache = config.services.noisebell-cache;
+  cfgRss = config.services.noisebell-rss;
   cfgDiscord = config.services.noisebell-discord;
 in
 {
@@ -11,6 +12,7 @@ in
   users.groups.noisebell = { };
 
   users.users.noisebell-cache.extraGroups = lib.mkIf cfgCache.enable [ "noisebell" ];
+  users.users.noisebell-rss.extraGroups = lib.mkIf cfgRss.enable [ "noisebell" ];
   users.users.noisebell-discord.extraGroups = lib.mkIf cfgDiscord.enable [ "noisebell" ];
 
   age.secrets.noisebell-pi-to-cache-key = {
@@ -48,6 +50,12 @@ in
     );
   };
 
+  services.noisebell-rss = lib.mkIf cfgRss.enable (
+    lib.optionalAttrs cfgCache.enable {
+      cacheUrl = lib.mkDefault "http://127.0.0.1:${toString cfgCache.port}";
+    }
+  );
+
   services.noisebell-discord = lib.mkIf cfgDiscord.enable (
     {
       discordTokenFile = lib.mkDefault config.age.secrets.noisebell-discord-token.path;

remote/noisebell-common/Cargo.toml

@@ -3,6 +3,9 @@ name = "noisebell-common"
 version = "0.1.0"
 edition = "2021"
 
+[lints]
+workspace = true
+
 [dependencies]
 axum = "0.8"
 serde = { version = "1.0", features = ["derive"] }

remote/noisebell-common/src/lib.rs

@@ -148,10 +148,7 @@ mod tests {
     fn door_status_round_trips() {
         for status in DoorStatus::ALL {
             assert_eq!(status.as_str().parse::<DoorStatus>().unwrap(), status);
-            assert_eq!(
-                serde_json::to_string(&status).unwrap(),
-                format!("\"{status}\"")
-            );
+            assert_eq!(serde_json::to_string(&status).unwrap(), format!("\"{status}\""));
         }
     }
 
@@ -163,10 +160,7 @@ mod tests {
 
     #[test]
     fn webhook_payload_round_trips() {
-        let payload = WebhookPayload {
-            status: DoorStatus::Open,
-            timestamp: 1234567890,
-        };
+        let payload = WebhookPayload { status: DoorStatus::Open, timestamp: 1234567890 };
         let json = serde_json::to_string(&payload).unwrap();
         let deserialized: WebhookPayload = serde_json::from_str(&json).unwrap();
         assert_eq!(deserialized.status, DoorStatus::Open);

remote/rss-service/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "noisebell-rss"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+anyhow = "1.0"
+axum = "0.8"
+chrono = "0.4"
+noisebell-common = { path = "../noisebell-common" }
+reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
+tokio = { version = "1", features = ["rt-multi-thread", "macros", "net", "signal", "time"] }
+tower-http = { version = "0.6", features = ["trace"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }

remote/rss-service/README.md

@@ -0,0 +1,74 @@
+# RSS Service
+
+Serves public feed endpoints for Noisebell.
+
+This service does not store history. On each request it fetches the current state from `cache-service` and renders that one current state as RSS or Atom.
+
+## States
+
+- `open`: Noisebridge is open right now.
+- `closed`: Noisebridge is closed right now.
+- `offline`: the cache cannot currently confirm the Pi state.
+
+## Feed behavior
+
+- Feeds are current-state only, not historical archives.
+- Each feed emits either one item or zero items.
+- The item `guid` changes when the current status event changes, so feed readers can treat it as new.
+- Filtered feeds omit the item when the current state does not match that feed.
+
+## Endpoints
+
+| Format | Purpose | Path |
+|--------|---------|------|
+| JSON | Current status passthrough | `/status` |
+| RSS | All states | `/all/rss.xml` |
+| Atom | All states | `/all/atom.xml` |
+| RSS | Open + closed only | `/door/rss.xml` |
+| Atom | Open + closed only | `/door/atom.xml` |
+| RSS | Open only | `/open/rss.xml` |
+| Atom | Open only | `/open/atom.xml` |
+| HTTP | Health check | `/health` |
+| HTTP | Redirect to docs | `/` |
+
+Current aliases:
+
+- `/rss.xml` currently serves the same feed as `/all/rss.xml`.
+- `/atom.xml` currently serves the same feed as `/all/atom.xml`.
+- `/` redirects to the repo README for this module.
+
+## Feed text
+
+Items use custom titles:
+
+- `Noisebridge opened`
+- `Noisebridge closed`
+- `Noisebridge sensor went offline`
+
+Descriptions include:
+
+- the current state
+- when that state began, if known
+- when the cache last confirmed the state
+
+## Caching and polling hints
+
+- RSS includes `<ttl>1`, which suggests a 1-minute polling interval.
+- HTTP responses include `Cache-Control: public, max-age=60`.
+- HTTP responses also include `ETag` and `Last-Modified` so clients can revalidate cheaply.
+
+## Atom vs RSS
+
+RSS and Atom are both XML feed formats.
+
+- RSS is older and very widely supported.
+- Atom is newer and has a more regular structure.
+- For this service they contain the same information in two different standard formats.
+
+## Configuration
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `NOISEBELL_RSS_CACHE_URL` | required | Base URL of `cache-service` |
+| `NOISEBELL_RSS_PORT` | `3002` | Listen port |
+| `NOISEBELL_RSS_HTTP_TIMEOUT_SECS` | `10` | Timeout when requesting cache status |

remote/rss-service/module.nix

@@ -0,0 +1,75 @@
+pkg:
+{ config, lib, ... }:
+
+let
+  cfg = config.services.noisebell-rss;
+  bin = "${pkg}/bin/noisebell-rss";
+in
+{
+  options.services.noisebell-rss = {
+    enable = lib.mkEnableOption "noisebell RSS service";
+
+    domain = lib.mkOption {
+      type = lib.types.str;
+      description = "Domain for the Caddy virtual host.";
+    };
+
+    port = lib.mkOption {
+      type = lib.types.port;
+      default = 3002;
+    };
+
+    cacheUrl = lib.mkOption {
+      type = lib.types.str;
+      description = "URL of the cache service (e.g. http://localhost:3000).";
+    };
+
+    httpTimeoutSecs = lib.mkOption {
+      type = lib.types.ints.positive;
+      default = 10;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    users.users.noisebell-rss = {
+      isSystemUser = true;
+      group = "noisebell-rss";
+    };
+    users.groups.noisebell-rss = { };
+
+    services.caddy.virtualHosts.${cfg.domain}.extraConfig = ''
+      reverse_proxy localhost:${toString cfg.port}
+    '';
+
+    systemd.services.noisebell-rss = {
+      description = "Noisebell RSS service";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network-online.target" ];
+      wants = [ "network-online.target" ];
+      environment = {
+        NOISEBELL_RSS_PORT = toString cfg.port;
+        NOISEBELL_RSS_CACHE_URL = cfg.cacheUrl;
+        NOISEBELL_RSS_HTTP_TIMEOUT_SECS = toString cfg.httpTimeoutSecs;
+        RUST_LOG = "info";
+      };
+      script = ''
+        exec ${bin}
+      '';
+      serviceConfig = {
+        Type = "simple";
+        Restart = "on-failure";
+        RestartSec = 5;
+        User = "noisebell-rss";
+        Group = "noisebell-rss";
+        NoNewPrivileges = true;
+        ProtectSystem = "strict";
+        ProtectHome = true;
+        PrivateTmp = true;
+        ProtectKernelTunables = true;
+        ProtectKernelModules = true;
+        ProtectControlGroups = true;
+        RestrictSUIDSGID = true;
+      };
+    };
+  };
+}

remote/rss-service/src/main.rs

@@ -0,0 +1,677 @@
+use std::sync::Arc;
+use std::time::Duration;
+
+use anyhow::{Context, Result};
+use axum::extract::State;
+use axum::http::{header, HeaderMap, HeaderValue, StatusCode};
+use axum::response::{IntoResponse, Redirect, Response};
+use axum::routing::get;
+use axum::{Json, Router};
+use chrono::{DateTime, Utc};
+use noisebell_common::{CacheStatusResponse, DoorStatus};
+use tower_http::trace::TraceLayer;
+use tracing::{error, info, Level};
+
+const FEED_TTL_MINUTES: u32 = 1;
+const README_URL: &str =
+    "https://git.extremist.software/jet/noisebell/src/branch/main/remote/rss-service/README.md";
+
+struct AppState {
+    cache_url: String,
+    client: reqwest::Client,
+}
+
+#[derive(Clone, Copy)]
+enum FeedFormat {
+    Rss,
+    Atom,
+}
+
+#[derive(Clone, Copy)]
+enum FeedKind {
+    All,
+    Door,
+    Open,
+}
+
+#[derive(Clone, Copy)]
+struct FeedSpec {
+    kind: FeedKind,
+    format: FeedFormat,
+    path: &'static str,
+}
+
+struct FeedDocument {
+    body: String,
+    etag: String,
+    last_modified: String,
+    content_type: &'static str,
+}
+
+fn unix_now() -> u64 {
+    std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap().as_secs()
+}
+
+fn format_full_timestamp(ts: u64) -> String {
+    DateTime::from_timestamp(ts as i64, 0)
+        .map(|dt: DateTime<Utc>| dt.format("%A, %B %-d, %Y at %-I:%M:%S %p UTC").to_string())
+        .unwrap_or_else(|| format!("unix timestamp {ts}"))
+}
+
+fn format_rfc2822_timestamp(ts: u64) -> String {
+    DateTime::from_timestamp(ts as i64, 0)
+        .map(|dt: DateTime<Utc>| dt.to_rfc2822())
+        .unwrap_or_else(|| "Thu, 01 Jan 1970 00:00:00 +0000".to_string())
+}
+
+fn format_rfc3339_timestamp(ts: u64) -> String {
+    DateTime::from_timestamp(ts as i64, 0)
+        .map(|dt: DateTime<Utc>| dt.to_rfc3339())
+        .unwrap_or_else(|| "1970-01-01T00:00:00+00:00".to_string())
+}
+
+fn format_duration(seconds: u64) -> String {
+    let units = [(86_400, "day"), (3_600, "hour"), (60, "minute"), (1, "second")];
+
+    let mut remaining = seconds;
+    let mut parts = Vec::new();
+
+    for (unit_seconds, name) in units {
+        if remaining >= unit_seconds {
+            let count = remaining / unit_seconds;
+            remaining %= unit_seconds;
+            let suffix = if count == 1 { "" } else { "s" };
+            parts.push(format!("{count} {name}{suffix}"));
+        }
+
+        if parts.len() == 2 {
+            break;
+        }
+    }
+
+    if parts.is_empty() {
+        "0 seconds".to_string()
+    } else if parts.len() == 1 {
+        parts.remove(0)
+    } else {
+        format!("{} and {}", parts[0], parts[1])
+    }
+}
+
+fn xml_escape(text: &str) -> String {
+    let mut escaped = String::with_capacity(text.len());
+    for ch in text.chars() {
+        match ch {
+            '&' => escaped.push_str("&amp;"),
+            '<' => escaped.push_str("&lt;"),
+            '>' => escaped.push_str("&gt;"),
+            '"' => escaped.push_str("&quot;"),
+            '\'' => escaped.push_str("&apos;"),
+            _ => escaped.push(ch),
+        }
+    }
+    escaped
+}
+
+fn header_value(headers: &HeaderMap, name: &'static str) -> Option<String> {
+    headers
+        .get(name)
+        .and_then(|value| value.to_str().ok())
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .map(ToOwned::to_owned)
+}
+
+fn public_base_url(headers: &HeaderMap) -> String {
+    let host = header_value(headers, "x-forwarded-host")
+        .or_else(|| header_value(headers, "host"))
+        .unwrap_or_else(|| "localhost:3002".to_string());
+    let scheme = header_value(headers, "x-forwarded-proto").unwrap_or_else(|| "http".to_string());
+    format!("{scheme}://{host}")
+}
+
+fn item_timestamp(status: &CacheStatusResponse) -> u64 {
+    status.since.or(status.last_checked).unwrap_or(0)
+}
+
+fn item_guid(status: &CacheStatusResponse) -> String {
+    let ts = item_timestamp(status);
+    format!("urn:noisebell:status:{}:{ts}", status.status.as_str())
+}
+
+fn feed_kind_slug(kind: FeedKind) -> &'static str {
+    match kind {
+        FeedKind::All => "all",
+        FeedKind::Door => "door",
+        FeedKind::Open => "open",
+    }
+}
+
+fn feed_title(kind: FeedKind) -> &'static str {
+    match kind {
+        FeedKind::All => "Noisebell all status feed",
+        FeedKind::Door => "Noisebell door state feed",
+        FeedKind::Open => "Noisebell open-only feed",
+    }
+}
+
+fn feed_description(kind: FeedKind) -> &'static str {
+    match kind {
+        FeedKind::All => "Current Noisebell state including open, closed, and offline.",
+        FeedKind::Door => "Current Noisebell door state, limited to open and closed.",
+        FeedKind::Open => "Current Noisebell state when the space is open.",
+    }
+}
+
+fn feed_self_path(spec: FeedSpec) -> &'static str {
+    spec.path
+}
+
+fn feed_alt_path(kind: FeedKind, format: FeedFormat) -> &'static str {
+    match (kind, format) {
+        (FeedKind::All, FeedFormat::Rss) => "/all/rss.xml",
+        (FeedKind::All, FeedFormat::Atom) => "/all/atom.xml",
+        (FeedKind::Door, FeedFormat::Rss) => "/door/",
+        (FeedKind::Door, FeedFormat::Atom) => "/door/atom.xml",
+        (FeedKind::Open, FeedFormat::Rss) => "/open/",
+        (FeedKind::Open, FeedFormat::Atom) => "/open/atom.xml",
+    }
+}
+
+fn matches_feed(kind: FeedKind, status: DoorStatus) -> bool {
+    match kind {
+        FeedKind::All => true,
+        FeedKind::Door => matches!(status, DoorStatus::Open | DoorStatus::Closed),
+        FeedKind::Open => status == DoorStatus::Open,
+    }
+}
+
+fn custom_item_title(status: DoorStatus) -> &'static str {
+    match status {
+        DoorStatus::Open => "Noisebridge opened",
+        DoorStatus::Closed => "Noisebridge closed",
+        DoorStatus::Offline => "Noisebridge sensor went offline",
+    }
+}
+
+fn richer_item_text(status: &CacheStatusResponse, now: u64) -> String {
+    let since_sentence = status
+        .since
+        .map(|ts| {
+            format!(
+                "The current state became {} at {}, about {} ago.",
+                status.status,
+                format_full_timestamp(ts),
+                format_duration(now.saturating_sub(ts)),
+            )
+        })
+        .unwrap_or_else(|| {
+            format!("The current state is {}, but the start time is unknown.", status.status)
+        });
+
+    let checked_sentence = status
+        .last_checked
+        .map(|ts| {
+            format!(
+                "The cache last confirmed this at {}, about {} ago.",
+                format_full_timestamp(ts),
+                format_duration(now.saturating_sub(ts)),
+            )
+        })
+        .unwrap_or_else(|| "The cache has no recorded last-checked time yet.".to_string());
+
+    let lead = match status.status {
+        DoorStatus::Open => "Noisebridge is open right now.",
+        DoorStatus::Closed => "Noisebridge is closed right now.",
+        DoorStatus::Offline => "Noisebridge is currently offline right now.",
+    };
+
+    format!("{lead} {since_sentence} {checked_sentence}")
+}
+
+fn effective_human_readable(status: &CacheStatusResponse, now: u64) -> String {
+    if status.human_readable.is_empty() {
+        richer_item_text(status, now)
+    } else {
+        status.human_readable.clone()
+    }
+}
+
+fn build_rss_item(base_url: &str, status: &CacheStatusResponse, now: u64) -> String {
+    let ts = item_timestamp(status);
+    let pub_date = format_rfc2822_timestamp(ts);
+    let link = format!("{base_url}/status");
+    let guid = item_guid(status);
+    let title = custom_item_title(status.status);
+    let description = richer_item_text(status, now);
+
+    format!(
+        concat!(
+            "    <item>\n",
+            "      <title>{title}</title>\n",
+            "      <link>{link}</link>\n",
+            "      <guid isPermaLink=\"false\">{guid}</guid>\n",
+            "      <pubDate>{pub_date}</pubDate>\n",
+            "      <description>{description}</description>\n",
+            "    </item>\n"
+        ),
+        title = xml_escape(title),
+        link = xml_escape(&link),
+        guid = xml_escape(&guid),
+        pub_date = xml_escape(&pub_date),
+        description = xml_escape(&description),
+    )
+}
+
+fn build_rss_feed(
+    base_url: &str,
+    spec: FeedSpec,
+    status: &CacheStatusResponse,
+    now: u64,
+) -> FeedDocument {
+    let ts = item_timestamp(status);
+    let pub_date = format_rfc2822_timestamp(ts);
+    let self_url = format!("{base_url}{}", feed_self_path(spec));
+    let atom_alt_url = format!("{base_url}{}", feed_alt_path(spec.kind, FeedFormat::Atom));
+    let item = if matches_feed(spec.kind, status.status) {
+        build_rss_item(base_url, status, now)
+    } else {
+        String::new()
+    };
+    let etag = format!("\"rss:{}:{}:{}\"", feed_kind_slug(spec.kind), status.status.as_str(), ts);
+    let body = format!(
+        concat!(
+            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n",
+            "<rss version=\"2.0\" xmlns:atom=\"http://www.w3.org/2005/Atom\">\n",
+            "  <channel>\n",
+            "    <title>{title}</title>\n",
+            "    <link>{self_url}</link>\n",
+            "    <description>{description}</description>\n",
+            "    <lastBuildDate>{pub_date}</lastBuildDate>\n",
+            "    <ttl>{ttl}</ttl>\n",
+            "    <atom:link href=\"{self_url_attr}\" rel=\"self\" type=\"application/rss+xml\" />\n",
+            "    <atom:link href=\"{atom_url_attr}\" rel=\"alternate\" type=\"application/atom+xml\" />\n",
+            "{item}",
+            "  </channel>\n",
+            "</rss>\n"
+        ),
+        title = xml_escape(feed_title(spec.kind)),
+        self_url = xml_escape(&self_url),
+        description = xml_escape(feed_description(spec.kind)),
+        pub_date = xml_escape(&pub_date),
+        ttl = FEED_TTL_MINUTES,
+        self_url_attr = xml_escape(&self_url),
+        atom_url_attr = xml_escape(&atom_alt_url),
+        item = item,
+    );
+
+    FeedDocument {
+        body,
+        etag,
+        last_modified: pub_date,
+        content_type: "application/rss+xml; charset=utf-8",
+    }
+}
+
+fn build_atom_entry(base_url: &str, status: &CacheStatusResponse, now: u64) -> String {
+    let ts = item_timestamp(status);
+    let updated = format_rfc3339_timestamp(ts);
+    let link = format!("{base_url}/status");
+    let guid = item_guid(status);
+    let title = custom_item_title(status.status);
+    let description = richer_item_text(status, now);
+
+    format!(
+        concat!(
+            "  <entry>\n",
+            "    <title>{title}</title>\n",
+            "    <id>{guid}</id>\n",
+            "    <updated>{updated}</updated>\n",
+            "    <link href=\"{link_attr}\" />\n",
+            "    <summary>{description}</summary>\n",
+            "  </entry>\n"
+        ),
+        title = xml_escape(title),
+        guid = xml_escape(&guid),
+        updated = xml_escape(&updated),
+        link_attr = xml_escape(&link),
+        description = xml_escape(&description),
+    )
+}
+
+fn build_atom_feed(
+    base_url: &str,
+    spec: FeedSpec,
+    status: &CacheStatusResponse,
+    now: u64,
+) -> FeedDocument {
+    let ts = item_timestamp(status);
+    let updated = format_rfc3339_timestamp(ts);
+    let self_url = format!("{base_url}{}", feed_self_path(spec));
+    let rss_alt_url = format!("{base_url}{}", feed_alt_path(spec.kind, FeedFormat::Rss));
+    let id = format!("urn:noisebell:feed:{}", feed_kind_slug(spec.kind));
+    let entry = if matches_feed(spec.kind, status.status) {
+        build_atom_entry(base_url, status, now)
+    } else {
+        String::new()
+    };
+    let etag = format!("\"atom:{}:{}:{}\"", feed_kind_slug(spec.kind), status.status.as_str(), ts);
+    let body = format!(
+        concat!(
+            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n",
+            "<feed xmlns=\"http://www.w3.org/2005/Atom\">\n",
+            "  <title>{title}</title>\n",
+            "  <id>{id}</id>\n",
+            "  <updated>{updated}</updated>\n",
+            "  <link href=\"{self_url_attr}\" rel=\"self\" />\n",
+            "  <link href=\"{rss_url_attr}\" rel=\"alternate\" type=\"application/rss+xml\" />\n",
+            "  <subtitle>{description}</subtitle>\n",
+            "{entry}",
+            "</feed>\n"
+        ),
+        title = xml_escape(feed_title(spec.kind)),
+        id = xml_escape(&id),
+        updated = xml_escape(&updated),
+        self_url_attr = xml_escape(&self_url),
+        rss_url_attr = xml_escape(&rss_alt_url),
+        description = xml_escape(feed_description(spec.kind)),
+        entry = entry,
+    );
+
+    FeedDocument {
+        body,
+        etag,
+        last_modified: format_rfc2822_timestamp(ts),
+        content_type: "application/atom+xml; charset=utf-8",
+    }
+}
+
+fn build_feed_document(
+    base_url: &str,
+    spec: FeedSpec,
+    status: &CacheStatusResponse,
+    now: u64,
+) -> FeedDocument {
+    match spec.format {
+        FeedFormat::Rss => build_rss_feed(base_url, spec, status, now),
+        FeedFormat::Atom => build_atom_feed(base_url, spec, status, now),
+    }
+}
+
+fn header_matches(headers: &HeaderMap, name: &'static str, expected: &str) -> bool {
+    headers
+        .get(name)
+        .and_then(|value| value.to_str().ok())
+        .map(str::trim)
+        .map(|value| value == expected)
+        .unwrap_or(false)
+}
+
+fn response_with_cache(headers: &HeaderMap, document: FeedDocument) -> Response {
+    if header_matches(headers, "if-none-match", &document.etag) {
+        return (
+            StatusCode::NOT_MODIFIED,
+            [
+                (header::ETAG, document.etag),
+                (header::LAST_MODIFIED, document.last_modified),
+                (header::CACHE_CONTROL, "public, max-age=60".to_string()),
+            ],
+        )
+            .into_response();
+    }
+
+    let mut response = document.body.into_response();
+    response
+        .headers_mut()
+        .insert(header::CONTENT_TYPE, HeaderValue::from_static(document.content_type));
+    response
+        .headers_mut()
+        .insert(header::CACHE_CONTROL, HeaderValue::from_static("public, max-age=60"));
+    response
+        .headers_mut()
+        .insert(header::ETAG, HeaderValue::from_str(&document.etag).expect("etag is always valid"));
+    response.headers_mut().insert(
+        header::LAST_MODIFIED,
+        HeaderValue::from_str(&document.last_modified).expect("last-modified is always valid"),
+    );
+    response
+}
+
+async fn fetch_status(state: &AppState) -> Result<CacheStatusResponse, StatusCode> {
+    let url = format!("{}/status", state.cache_url);
+    let response = state.client.get(&url).send().await.map_err(|e| {
+        error!(error = %e, %url, "failed to reach cache service");
+        StatusCode::BAD_GATEWAY
+    })?;
+
+    if !response.status().is_success() {
+        error!(status = %response.status(), %url, "cache service returned non-success status");
+        return Err(StatusCode::BAD_GATEWAY);
+    }
+
+    response.json::<CacheStatusResponse>().await.map_err(|e| {
+        error!(error = %e, %url, "failed to parse cache status response");
+        StatusCode::BAD_GATEWAY
+    })
+}
+
+async fn health() -> StatusCode {
+    StatusCode::OK
+}
+
+async fn root_redirect() -> Redirect {
+    Redirect::temporary(README_URL)
+}
+
+async fn get_status(
+    State(state): State<Arc<AppState>>,
+) -> Result<Json<CacheStatusResponse>, StatusCode> {
+    let mut status = fetch_status(&state).await?;
+    status.human_readable = effective_human_readable(&status, unix_now());
+    Ok(Json(status))
+}
+
+async fn serve_feed(
+    State(state): State<Arc<AppState>>,
+    headers: HeaderMap,
+    spec: FeedSpec,
+) -> Result<Response, StatusCode> {
+    let mut status = fetch_status(&state).await?;
+    let now = unix_now();
+    status.human_readable = effective_human_readable(&status, now);
+    let base_url = public_base_url(&headers);
+    let document = build_feed_document(&base_url, spec, &status, now);
+    Ok(response_with_cache(&headers, document))
+}
+
+async fn get_all_rss(
+    state: State<Arc<AppState>>,
+    headers: HeaderMap,
+) -> Result<Response, StatusCode> {
+    serve_feed(state, headers, FeedSpec { kind: FeedKind::All, format: FeedFormat::Rss, path: "/" })
+        .await
+}
+
+async fn get_all_atom(
+    state: State<Arc<AppState>>,
+    headers: HeaderMap,
+) -> Result<Response, StatusCode> {
+    serve_feed(
+        state,
+        headers,
+        FeedSpec { kind: FeedKind::All, format: FeedFormat::Atom, path: "/atom.xml" },
+    )
+    .await
+}
+
+async fn get_door_rss(
+    state: State<Arc<AppState>>,
+    headers: HeaderMap,
+) -> Result<Response, StatusCode> {
+    serve_feed(
+        state,
+        headers,
+        FeedSpec { kind: FeedKind::Door, format: FeedFormat::Rss, path: "/door/" },
+    )
+    .await
+}
+
+async fn get_door_atom(
+    state: State<Arc<AppState>>,
+    headers: HeaderMap,
+) -> Result<Response, StatusCode> {
+    serve_feed(
+        state,
+        headers,
+        FeedSpec { kind: FeedKind::Door, format: FeedFormat::Atom, path: "/door/atom.xml" },
+    )
+    .await
+}
+
+async fn get_open_rss(
+    state: State<Arc<AppState>>,
+    headers: HeaderMap,
+) -> Result<Response, StatusCode> {
+    serve_feed(
+        state,
+        headers,
+        FeedSpec { kind: FeedKind::Open, format: FeedFormat::Rss, path: "/open/" },
+    )
+    .await
+}
+
+async fn get_open_atom(
+    state: State<Arc<AppState>>,
+    headers: HeaderMap,
+) -> Result<Response, StatusCode> {
+    serve_feed(
+        state,
+        headers,
+        FeedSpec { kind: FeedKind::Open, format: FeedFormat::Atom, path: "/open/atom.xml" },
+    )
+    .await
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    tracing_subscriber::fmt()
+        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
+        .init();
+
+    let port: u16 = std::env::var("NOISEBELL_RSS_PORT")
+        .unwrap_or_else(|_| "3002".into())
+        .parse()
+        .context("NOISEBELL_RSS_PORT must be a valid u16")?;
+
+    let cache_url = std::env::var("NOISEBELL_RSS_CACHE_URL")
+        .context("NOISEBELL_RSS_CACHE_URL is required")?
+        .trim_end_matches('/')
+        .to_string();
+
+    let http_timeout_secs: u64 = std::env::var("NOISEBELL_RSS_HTTP_TIMEOUT_SECS")
+        .unwrap_or_else(|_| "10".into())
+        .parse()
+        .context("NOISEBELL_RSS_HTTP_TIMEOUT_SECS must be a valid u64")?;
+
+    info!(port, %cache_url, ttl_minutes = FEED_TTL_MINUTES, "starting noisebell-rss");
+
+    let client = reqwest::Client::builder()
+        .timeout(Duration::from_secs(http_timeout_secs))
+        .build()
+        .context("failed to build HTTP client")?;
+
+    let app_state = Arc::new(AppState { cache_url, client });
+
+    let app = Router::new()
+        .route("/health", get(health))
+        .route("/status", get(get_status))
+        .route("/", get(root_redirect))
+        .route("/rss.xml", get(get_all_rss))
+        .route("/atom.xml", get(get_all_atom))
+        .route("/all/rss.xml", get(get_all_rss))
+        .route("/all/atom.xml", get(get_all_atom))
+        .route("/door/", get(get_door_rss))
+        .route("/door/rss.xml", get(get_door_rss))
+        .route("/door/atom.xml", get(get_door_atom))
+        .route("/open/", get(get_open_rss))
+        .route("/open/rss.xml", get(get_open_rss))
+        .route("/open/atom.xml", get(get_open_atom))
+        .layer(
+            TraceLayer::new_for_http()
+                .make_span_with(tower_http::trace::DefaultMakeSpan::new().level(Level::INFO))
+                .on_response(tower_http::trace::DefaultOnResponse::new().level(Level::INFO)),
+        )
+        .with_state(app_state);
+
+    let listener = tokio::net::TcpListener::bind(("0.0.0.0", port))
+        .await
+        .context(format!("failed to bind to 0.0.0.0:{port}"))?;
+
+    info!(port, "listening");
+
+    let mut sigterm = tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
+        .context("failed to register SIGTERM handler")?;
+    axum::serve(listener, app)
+        .with_graceful_shutdown(async move {
+            sigterm.recv().await;
+        })
+        .await
+        .context("server error")?;
+
+    info!("shutdown complete");
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn sample_status(status: DoorStatus) -> CacheStatusResponse {
+        CacheStatusResponse {
+            status,
+            since: Some(1_700_000_000),
+            last_checked: Some(1_700_000_120),
+            human_readable: String::new(),
+        }
+    }
+
+    #[test]
+    fn open_feed_omits_closed_item() {
+        let feed = build_rss_feed(
+            "https://rss.example.com",
+            FeedSpec { kind: FeedKind::Open, format: FeedFormat::Rss, path: "/open/" },
+            &sample_status(DoorStatus::Closed),
+            1_700_000_200,
+        );
+
+        assert_eq!(feed.body.matches("<item>").count(), 0);
+    }
+
+    #[test]
+    fn all_rss_feed_contains_custom_title() {
+        let feed = build_rss_feed(
+            "https://rss.example.com",
+            FeedSpec { kind: FeedKind::All, format: FeedFormat::Rss, path: "/" },
+            &sample_status(DoorStatus::Open),
+            1_700_000_200,
+        );
+
+        assert!(feed.body.contains("<title>Noisebridge opened</title>"));
+        assert!(feed.body.contains("<ttl>1</ttl>"));
+        assert!(feed.body.contains("/atom.xml"));
+    }
+
+    #[test]
+    fn atom_feed_contains_entry() {
+        let feed = build_atom_feed(
+            "https://rss.example.com",
+            FeedSpec { kind: FeedKind::Door, format: FeedFormat::Atom, path: "/door/atom.xml" },
+            &sample_status(DoorStatus::Closed),
+            1_700_000_200,
+        );
+
+        assert!(feed.body.contains("<feed xmlns=\"http://www.w3.org/2005/Atom\">"));
+        assert!(feed.body.contains("<entry>"));
+        assert!(feed.body.contains("Noisebridge closed"));
+    }
+}

rustfmt.toml

@@ -0,0 +1,2 @@
+max_width = 100
+use_small_heuristics = "Max"