feat: add resource limits management and network client integration

- Introduced a new module for managing process resource limits, specifically for raising the open file limit on Unix systems.
- Added a `NetworkClients` struct to handle reusable outbound HTTP clients, improving network request management.
- Updated various components, including `ControlService` and `CursorProxy`, to utilize the new network client structure for better client handling.
- Enhanced the API router to accept network clients, ensuring consistent client usage across different services.
- Added tests to validate the integration of network clients and resource limits functionality.

server/src/api/cursor/handlers.rs

@@ -27,8 +27,11 @@ use crate::{
     Result,
 };
 
-pub fn router(registry: TransportRegistry) -> Result<Router> {
-    let proxy = CursorProxy::cursor(registry.store().clone())?;
+pub fn router(
+    registry: TransportRegistry,
+    clients: crate::network::NetworkClients,
+) -> Result<Router> {
+    let proxy = CursorProxy::cursor(clients);
     let knowledge = knowledge::KnowledgeService::managed()?;
     Ok(router_with_proxy(registry, proxy, knowledge))
 }

server/src/api/cursor/proxy.rs

@@ -14,8 +14,7 @@ pub const UPSTREAM_URL_HEADER: &str = "x-server-upstream-url";
 
 #[derive(Clone)]
 pub struct CursorProxy {
-    client: Option<reqwest::Client>,
-    store: Option<crate::store::Store>,
+    clients: crate::network::NetworkClients,
     upstream: String,
 }
 
@@ -47,23 +46,15 @@ impl BufferedResponse {
 }
 
 impl CursorProxy {
-    pub fn cursor(store: crate::store::Store) -> Result<Self> {
-        Ok(Self {
-            client: None,
-            store: Some(store),
+    pub fn cursor(clients: crate::network::NetworkClients) -> Self {
+        Self {
+            clients,
             upstream: CURSOR_UPSTREAM.into(),
-        })
+        }
     }
 
     async fn client(&self) -> Result<reqwest::Client> {
-        match (&self.client, &self.store) {
-            (Some(client), _) => Ok(client.clone()),
-            (_, Some(store)) => Ok(crate::network::client_builder(store)
-                .await?
-                .redirect(reqwest::redirect::Policy::none())
-                .build()?),
-            _ => unreachable!("Cursor proxy always has a client or store"),
-        }
+        self.clients.cursor_client().await
     }
 }
 

server/src/api/router.rs

@@ -1,7 +1,7 @@
 //! Builds the top-level server router.
 
-use crate::{cursor::transport::TransportRegistry, Result};
+use crate::{cursor::transport::TransportRegistry, network::NetworkClients, Result};
 
-pub fn router(registry: TransportRegistry) -> Result<axum::Router> {
-    super::cursor::router(registry)
+pub fn router(registry: TransportRegistry, clients: NetworkClients) -> Result<axum::Router> {
+    super::cursor::router(registry, clients)
 }

server/src/app.rs

@@ -44,9 +44,11 @@ impl App {
             plugin_runtime.clone(),
             config.app_version.clone(),
         )?;
+        let clients = crate::network::NetworkClients::new(store.clone());
         let provider = std::sync::Arc::new(ProviderRouter::new(
             store.clone(),
             plugins.clone(),
+            clients.clone(),
             config.provider_request_timeout,
             config.provider_stream_idle_timeout,
         ));
@@ -58,10 +60,15 @@ impl App {
             plugins.clone(),
             crate::config::managed_data_dir()?.join("rules"),
         );
-        let control =
-            control::ControlService::new(store.clone(), provider, plugin_runtime, plugins)?;
+        let control = control::ControlService::new(
+            store.clone(),
+            provider,
+            plugin_runtime,
+            plugins,
+            clients.clone(),
+        )?;
         let harness = control.cursor_harness().clone();
-        let mut router = api::router(registry.clone())?;
+        let mut router = api::router(registry.clone(), clients)?;
         router = match &config.console {
             Some(ConsoleSource::Directory(directory)) => {
                 router.merge(control::web_router(control.clone(), directory))

server/src/control/service.rs

@@ -41,6 +41,7 @@ pub struct ControlService {
     provider: Arc<dyn Provider>,
     plugin_runtime: PluginRuntime,
     plugins: PluginRegistry,
+    clients: crate::network::NetworkClients,
     model_tests: Arc<Mutex<BTreeMap<String, CancellationToken>>>,
 }
 
@@ -151,6 +152,7 @@ impl ControlService {
         provider: Arc<dyn Provider>,
         plugin_runtime: PluginRuntime,
         plugins: PluginRegistry,
+        clients: crate::network::NetworkClients,
     ) -> Result<Self> {
         Ok(Self {
             cursor_harness: CursorHarness::new(store.clone())?,
@@ -158,6 +160,7 @@ impl ControlService {
             provider,
             plugin_runtime,
             plugins,
+            clients,
             model_tests: Arc::new(Mutex::new(BTreeMap::new())),
         })
     }
@@ -256,7 +259,7 @@ impl ControlService {
         disabled_ad_ids: Option<&str>,
         language: &str,
     ) -> Result<AdRuntime> {
-        let client = crate::network::client(&self.store).await?;
+        let client = self.clients.default_client().await?;
         let installation_id = self.store.installation_id().await?;
         let mut request = client
             .get(ADS_ENDPOINT)
@@ -281,7 +284,7 @@ impl ControlService {
     }
 
     pub(super) async fn dismiss_ad(&self, ad_id: &str, input: &AdDismissalInput) -> Result<()> {
-        let client = crate::network::client(&self.store).await?;
+        let client = self.clients.default_client().await?;
         let installation_id = self.store.installation_id().await?;
         let mut endpoint = Url::parse(ADS_ENDPOINT).map_err(|error| {
             Error::Config(format!("advertisement endpoint is invalid: {error}"))
@@ -510,7 +513,7 @@ impl ControlService {
     }
 
     pub async fn discover_models(&self, input: &ModelDiscoveryInput) -> Result<DiscoveredModels> {
-        let client = crate::network::client(&self.store).await?;
+        let client = self.clients.default_client().await?;
         let base_url = crate::model::normalize_request_url(&input.base_url)?;
         discover_models_from_endpoint(
             &client,
@@ -677,7 +680,9 @@ impl ControlService {
     }
 
     pub async fn set_proxy_settings(&self, settings: ProxySettingsInput) -> Result<ProxySettings> {
-        self.store.set_proxy_settings(settings).await
+        let settings = self.store.set_proxy_settings(settings).await?;
+        self.clients.invalidate().await;
+        Ok(settings)
     }
 
     pub async fn tab_settings(&self) -> Result<TabSettings> {

server/src/network.rs

@@ -1,8 +1,93 @@
-//! Provides shared network client and transport configuration.
-//! Outbound HTTP clients configured from persisted application proxy settings.
+//! Owns reusable outbound HTTP clients configured from persisted proxy settings.
+
+use std::{sync::Arc, time::Duration};
+
+use tokio::sync::RwLock;
 
 use crate::{store::Store, Result};
 
+#[derive(Clone)]
+pub struct NetworkClients {
+    store: Store,
+    cache: Arc<RwLock<ClientCache>>,
+}
+
+#[derive(Default)]
+struct ClientCache {
+    default: Option<reqwest::Client>,
+    cursor: Option<reqwest::Client>,
+    provider: Option<(Duration, reqwest::Client)>,
+}
+
+impl NetworkClients {
+    pub fn new(store: Store) -> Self {
+        Self {
+            store,
+            cache: Arc::new(RwLock::new(ClientCache::default())),
+        }
+    }
+
+    pub async fn default_client(&self) -> Result<reqwest::Client> {
+        if let Some(client) = self.cache.read().await.default.clone() {
+            return Ok(client);
+        }
+        let mut cache = self.cache.write().await;
+        if let Some(client) = cache.default.clone() {
+            return Ok(client);
+        }
+        let client = client_builder(&self.store).await?.build()?;
+        cache.default = Some(client.clone());
+        Ok(client)
+    }
+
+    pub async fn cursor_client(&self) -> Result<reqwest::Client> {
+        if let Some(client) = self.cache.read().await.cursor.clone() {
+            return Ok(client);
+        }
+        let mut cache = self.cache.write().await;
+        if let Some(client) = cache.cursor.clone() {
+            return Ok(client);
+        }
+        let client = client_builder(&self.store)
+            .await?
+            .redirect(reqwest::redirect::Policy::none())
+            .build()?;
+        cache.cursor = Some(client.clone());
+        Ok(client)
+    }
+
+    pub async fn provider_client(&self, timeout: Duration) -> Result<reqwest::Client> {
+        if let Some((_, client)) = self
+            .cache
+            .read()
+            .await
+            .provider
+            .as_ref()
+            .filter(|(cached_timeout, _)| *cached_timeout == timeout)
+        {
+            return Ok(client.clone());
+        }
+        let mut cache = self.cache.write().await;
+        if let Some((_, client)) = cache
+            .provider
+            .as_ref()
+            .filter(|(cached_timeout, _)| *cached_timeout == timeout)
+        {
+            return Ok(client.clone());
+        }
+        let client = client_builder(&self.store)
+            .await?
+            .timeout(timeout)
+            .build()?;
+        cache.provider = Some((timeout, client.clone()));
+        Ok(client)
+    }
+
+    pub async fn invalidate(&self) {
+        *self.cache.write().await = ClientCache::default();
+    }
+}
+
 pub async fn client_builder(store: &Store) -> Result<reqwest::ClientBuilder> {
     let settings = store.proxy_settings_secret().await?;
     // Use the platform TLS stack for compatibility with provider gateways that

server/src/provider/router.rs

@@ -21,6 +21,7 @@ use super::{
 pub struct ProviderRouter {
     store: Store,
     plugins: PluginRegistry,
+    clients: crate::network::NetworkClients,
     request_timeout: Duration,
     stream_idle_timeout: Duration,
 }
@@ -29,12 +30,14 @@ impl ProviderRouter {
     pub fn new(
         store: Store,
         plugins: PluginRegistry,
+        clients: crate::network::NetworkClients,
         request_timeout: Duration,
         stream_idle_timeout: Duration,
     ) -> Self {
         Self {
             store,
             plugins,
+            clients,
             request_timeout,
             stream_idle_timeout,
         }
@@ -49,6 +52,7 @@ impl Provider for ProviderRouter {
     ) -> ProviderStream {
         let store = self.store.clone();
         let plugins = self.plugins.clone();
+        let clients = self.clients.clone();
         let request_timeout = self.request_timeout;
         let stream_idle_timeout = self.stream_idle_timeout;
         Box::pin(try_stream! {
@@ -91,7 +95,7 @@ impl Provider for ProviderRouter {
                         request_timeout,
                         allowed_body_fields: None,
                     };
-                    let client = crate::network::client_builder(&store).await?.timeout(request_timeout).build()?;
+                    let client = clients.provider_client(request_timeout).await?;
                     let provider = build_observed(&config, recorder.clone(), client)?;
                     (recorder, guard, provider.stream(routed, cancellation.clone()))
                 };

server/tests/knowledge_rules.rs

@@ -106,7 +106,7 @@ async fn decode<M: Message + Default>(response: Response<Body>) -> M {
 #[tokio::test]
 async fn offline_crud_round_trip_persists_markdown() {
     let (_store_dir, store) = fixtures::temp_store().await;
-    let upstream = CursorProxy::cursor(store).unwrap();
+    let upstream = CursorProxy::cursor(cursor_server::network::NetworkClients::new(store));
     let rules_dir = tempfile::tempdir().unwrap();
     let rules_root = rules_dir.path().join("rules");
     let service = KnowledgeService::with_root(rules_root.clone()).unwrap();
@@ -193,7 +193,7 @@ async fn offline_crud_round_trip_persists_markdown() {
 #[tokio::test]
 async fn updating_missing_rule_reports_failure() {
     let (_store_dir, store) = fixtures::temp_store().await;
-    let upstream = CursorProxy::cursor(store).unwrap();
+    let upstream = CursorProxy::cursor(cursor_server::network::NetworkClients::new(store));
     let rules_dir = tempfile::tempdir().unwrap();
     let service = KnowledgeService::with_root(rules_dir.path().join("rules")).unwrap();