feat: wire config, component loading, and axum serve in main

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/server/Cargo.toml

@@ -5,6 +5,7 @@ edition.workspace = true
 authors.workspace = true
 
 [dependencies]
+anyhow = "1"
 async-trait = "0.1"
 axum = "0.8"
 futures = "0.3"
@@ -15,6 +16,7 @@ serde_json = "1"
 thiserror = "2"
 tokio = { version = "1", features = ["full"] }
 tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 wasmtime = { version = "45", features = ["component-model"] }
 wasmtime-wasi = "45"
 

crates/server/src/config.rs

@@ -0,0 +1,111 @@
+use std::net::SocketAddr;
+use std::path::PathBuf;
+use std::time::Duration;
+
+use crate::error::ConfigError;
+
+#[derive(Debug)]
+pub struct AppConfig {
+    pub listen: SocketAddr,
+    pub components_dir: PathBuf,
+    pub cache_ttl: Duration,
+    pub fetch_timeout: Duration,
+}
+
+impl AppConfig {
+    pub fn from_env() -> Result<Self, ConfigError> {
+        Self::from_lookup(|key| std::env::var(key).ok())
+    }
+
+    pub fn from_lookup(get: impl Fn(&str) -> Option<String>) -> Result<Self, ConfigError> {
+        let listen = match get("WHOAREYOU_LISTEN") {
+            Some(value) => value.parse().map_err(|err| ConfigError::Invalid {
+                key: "WHOAREYOU_LISTEN".to_string(),
+                message: format!("{err}"),
+            })?,
+            None => SocketAddr::from(([127, 0, 0, 1], 8080)),
+        };
+
+        let components_dir = get("WHOAREYOU_COMPONENTS_DIR")
+            .map(PathBuf::from)
+            .unwrap_or_else(|| PathBuf::from("components"));
+
+        let cache_ttl_hours: u64 = parse_or("WHOAREYOU_CACHE_TTL_HOURS", &get, 24)?;
+        let fetch_timeout_secs: u64 = parse_or("WHOAREYOU_FETCH_TIMEOUT_SECS", &get, 10)?;
+
+        Ok(Self {
+            listen,
+            components_dir,
+            cache_ttl: Duration::from_secs(cache_ttl_hours * 3600),
+            fetch_timeout: Duration::from_secs(fetch_timeout_secs),
+        })
+    }
+}
+
+fn parse_or(
+    key: &str,
+    get: &impl Fn(&str) -> Option<String>,
+    default: u64,
+) -> Result<u64, ConfigError> {
+    match get(key) {
+        Some(value) => value.parse().map_err(|err| ConfigError::Invalid {
+            key: key.to_string(),
+            message: format!("{err}"),
+        }),
+        None => Ok(default),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+
+    use super::*;
+
+    fn env<'a>(pairs: &'a [(&'a str, &'a str)]) -> impl Fn(&str) -> Option<String> + 'a {
+        let map: HashMap<String, String> = pairs
+            .iter()
+            .map(|(k, v)| (k.to_string(), v.to_string()))
+            .collect();
+
+        move |key: &str| map.get(key).cloned()
+    }
+
+    #[test]
+    fn defaults_apply_when_unset() {
+        let config = AppConfig::from_lookup(env(&[])).unwrap();
+
+        assert_eq!(config.listen.to_string(), "127.0.0.1:8080");
+        assert_eq!(
+            config.components_dir,
+            std::path::PathBuf::from("components")
+        );
+        assert_eq!(config.cache_ttl, std::time::Duration::from_secs(24 * 3600));
+        assert_eq!(config.fetch_timeout, std::time::Duration::from_secs(10));
+    }
+
+    #[test]
+    fn env_overrides_apply() {
+        let config = AppConfig::from_lookup(env(&[
+            ("WHOAREYOU_LISTEN", "0.0.0.0:9000"),
+            ("WHOAREYOU_COMPONENTS_DIR", "/opt/providers"),
+            ("WHOAREYOU_CACHE_TTL_HOURS", "1"),
+            ("WHOAREYOU_FETCH_TIMEOUT_SECS", "30"),
+        ]))
+        .unwrap();
+
+        assert_eq!(config.listen.to_string(), "0.0.0.0:9000");
+        assert_eq!(
+            config.components_dir,
+            std::path::PathBuf::from("/opt/providers")
+        );
+        assert_eq!(config.cache_ttl, std::time::Duration::from_secs(3600));
+        assert_eq!(config.fetch_timeout, std::time::Duration::from_secs(30));
+    }
+
+    #[test]
+    fn invalid_values_error() {
+        assert!(AppConfig::from_lookup(env(&[("WHOAREYOU_LISTEN", "not-an-addr")])).is_err());
+        assert!(AppConfig::from_lookup(env(&[("WHOAREYOU_CACHE_TTL_HOURS", "soon")])).is_err());
+    }
+}

crates/server/src/lib.rs

@@ -1,3 +1,4 @@
+pub mod config;
 pub mod error;
 pub mod fetch;
 pub mod http;

crates/server/src/main.rs

@@ -1 +1,67 @@
-fn main() {}
+use std::sync::Arc;
+
+use anyhow::Context;
+use tracing::info;
+use tracing_subscriber::EnvFilter;
+
+use whoareyou_server::config::AppConfig;
+use whoareyou_server::fetch::ReqwestFetcher;
+use whoareyou_server::service::{LookupService, ProviderHandle};
+use whoareyou_server::{http, wasm};
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info")),
+        )
+        .init();
+
+    let config = AppConfig::from_env()?;
+
+    let engine = wasm::engine()?;
+    let linker = wasm::linker(&engine)?;
+
+    wasm::spawn_epoch_thread(&engine);
+
+    let mut providers: Vec<Arc<dyn ProviderHandle>> = Vec::new();
+
+    let dir = std::fs::read_dir(&config.components_dir)
+        .with_context(|| format!("reading components dir {:?}", config.components_dir))?;
+
+    for entry in dir {
+        let path = entry?.path();
+
+        if path.extension().is_some_and(|ext| ext == "wasm") {
+            let provider = wasm::WasmProvider::load(&engine, &linker, &path)
+                .with_context(|| format!("loading component {path:?}"))?;
+
+            info!(
+                name = provider.name(),
+                version = provider.version(),
+                ?path,
+                "loaded provider"
+            );
+
+            providers.push(Arc::new(provider));
+        }
+    }
+
+    anyhow::ensure!(
+        !providers.is_empty(),
+        "no .wasm components found in {:?}",
+        config.components_dir
+    );
+
+    let fetcher = Arc::new(ReqwestFetcher::new(config.fetch_timeout)?);
+    let service = Arc::new(LookupService::new(providers, fetcher, config.cache_ttl));
+    let app = http::router(service);
+
+    let listener = tokio::net::TcpListener::bind(config.listen).await?;
+
+    info!("listening on http://{}", config.listen);
+
+    axum::serve(listener, app).await?;
+
+    Ok(())
+}