nice control flags

crates/service/web/storyteller_web/src/http_server/middleware/error_alerting_middleware/error_alerting_middleware.rs

@@ -7,6 +7,7 @@ use actix_web::Error;
 use pager::client::pager::Pager;
 
 use crate::http_server::common_responses::common_web_error::CommonWebError;
+use crate::state::flags::paging_flags::PagingFlags;
 use super::check_common_web_error::check_common_web_error;
 use super::check_status_code_fallback::check_status_code_fallback;
 
@@ -18,16 +19,20 @@ use super::check_status_code_fallback::check_status_code_fallback;
 /// 1. **Typed error matching** via downcast (e.g. `CommonWebError::ServerError`)
 /// 2. **Status code fallback** for untyped 500s that slip through
 ///
+/// Both `PagingFlags.is_paging_enabled` and `PagingFlags.is_paging_for_500s_enabled`
+/// must be true for any alerting to fire. Otherwise the middleware is a passthrough.
+///
 /// To add new error types, create a new `check_*.rs` matcher module and
 /// add a downcast branch in `check_ok_response_for_alerts` / `check_err_for_alerts`.
 #[derive(Clone)]
 pub struct ErrorAlertingMiddleware {
   pager: Pager,
+  paging_flags: PagingFlags,
 }
 
 impl ErrorAlertingMiddleware {
-  pub fn new(pager: Pager) -> Self {
-    Self { pager }
+  pub fn new(pager: Pager, paging_flags: PagingFlags) -> Self {
+    Self { pager, paging_flags }
   }
 }
 
@@ -47,6 +52,7 @@ impl<S, B> Transform<S, ServiceRequest> for ErrorAlertingMiddleware
     ready(Ok(ErrorAlertingService {
       service,
       pager: self.pager.clone(),
+      paging_flags: self.paging_flags.clone(),
     }))
   }
 }
@@ -56,6 +62,7 @@ impl<S, B> Transform<S, ServiceRequest> for ErrorAlertingMiddleware
 pub struct ErrorAlertingService<S> {
   service: S,
   pager: Pager,
+  paging_flags: PagingFlags,
 }
 
 impl<S, B> Service<ServiceRequest> for ErrorAlertingService<S>
@@ -71,6 +78,11 @@ impl<S, B> Service<ServiceRequest> for ErrorAlertingService<S>
   actix_service::forward_ready!(service);
 
   fn call(&self, req: ServiceRequest) -> Self::Future {
+    // Fast path: if paging is disabled, skip all inspection.
+    if !self.paging_flags.is_paging_enabled || !self.paging_flags.is_paging_for_500s_enabled {
+      return Box::pin(self.service.call(req));
+    }
+
     let method = req.method().to_string();
     let path = req.path().to_string();
     let pager = self.pager.clone();

crates/service/web/storyteller_web/src/main.rs

@@ -339,7 +339,7 @@ async fn main() -> AnyhowResult<()> {
     ServerEnvironment::Development => server_environment::ServerEnvironment::Development,
   };
 
-  let (pager, pager_worker) = build_pager(server_environment_typed);
+  let (pager, pager_worker, paging_flags) = build_pager(server_environment_typed);
 
   info!("Spawning pager worker thread.");
 
@@ -392,6 +392,9 @@ async fn main() -> AnyhowResult<()> {
     // Disable voice features
     disable_tts: easyenv::get_env_bool_or_default("DISABLE_TTS", false),
     disable_voice_conversion: easyenv::get_env_bool_or_default("DISABLE_VOICE_CONVERSION", false),
+
+    // Paging
+    paging: paging_flags,
   };
 
   let third_party_url_redirector = ThirdPartyUrlRedirector::new(server_environment);
@@ -626,11 +629,13 @@ pub async fn serve(server_state: ServerState) -> AnyhowResult<()>
     ServerEnvironment::Production => server_environment::ServerEnvironment::Production,
   };
 
-  let enable_error_alerting = easyenv::get_env_bool_or_default("ENABLE_ERROR_ALERTING_MIDDLEWARE", false);
+  let paging_flags_for_middleware = server_state.flags.paging.clone();
   let pager_for_middleware = server_state.pager.clone();
+  let enable_error_alerting = paging_flags_for_middleware.is_paging_enabled
+    && paging_flags_for_middleware.is_paging_for_500s_enabled;
 
   if enable_error_alerting {
-    info!("Error alerting middleware is ENABLED.");
+    info!("Error alerting middleware is ENABLED (ENABLE_PAGING=true, ENABLE_PAGING_FOR_500S=true).");
   }
 
   let server_state_arc = web::Data::new(Arc::new(server_state));
@@ -692,7 +697,7 @@ pub async fn serve(server_state: ServerState) -> AnyhowResult<()>
         .header("X-Build-Sha", server_state_arc.server_info.build_sha.clone()))
       .wrap(middleware::Condition::new(
         enable_error_alerting,
-        ErrorAlertingMiddleware::new(pager_for_middleware.clone()),
+        ErrorAlertingMiddleware::new(pager_for_middleware.clone(), paging_flags_for_middleware.clone()),
       ))
       .wrap(PushbackFilter::new(&server_state_arc.flags.clone()))
       .wrap(DisabledEndpointFilter::new(disabled_endpoints.clone()))

crates/service/web/storyteller_web/src/startup/build_pager.rs

@@ -4,20 +4,38 @@ use pager::client::pager_builder::PagerBuilder;
 use pager::worker::pager_worker::PagerWorker;
 use rootly_client::creds::rootly_api_key::RootlyApiKey;
 
-pub fn build_pager(server_environment: server_environment::ServerEnvironment) -> (Pager, PagerWorker) {
+use crate::state::flags::paging_flags::PagingFlags;
+
+pub fn build_pager(
+  server_environment: server_environment::ServerEnvironment,
+) -> (Pager, PagerWorker, PagingFlags) {
+  let paging_flags = PagingFlags::from_env();
+
+  info!("Paging flags: {:?}", paging_flags);
+
   let environment = if server_environment.is_deployed_in_production() {
     "production"
   } else {
     "development"
   };
 
+  // If paging is globally disabled, use a NoOp pager regardless of API key.
+  if !paging_flags.is_paging_enabled {
+    warn!("ENABLE_PAGING is false. Pager will be NoOp.");
+    let (pager, worker) = PagerBuilder::new()
+      .application_name("storyteller-web".to_string())
+      .environment(environment.to_string())
+      .build_with_worker();
+    return (pager, worker, paging_flags);
+  }
+
   let maybe_api_key = easyenv::get_env_string_optional("ROOTLY_API_KEY");
 
   let builder = PagerBuilder::new()
       .application_name("storyteller-web".to_string())
       .environment(environment.to_string());
 
-  match maybe_api_key {
+  let (pager, worker) = match maybe_api_key {
     Some(api_key) => {
       info!("Rootly API key found. Configuring pager with Rootly backend.");
       build_rootly_pager(builder, api_key)
@@ -26,10 +44,12 @@ pub fn build_pager(server_environment: server_environment::ServerEnvironment) ->
       warn!("ROOTLY_API_KEY not set. Pager will not send real pages.");
       builder.build_with_worker()
     }
-  }
+  };
+
+  (pager, worker, paging_flags)
 }
 
-fn build_rootly_pager(mut builder: PagerBuilder, api_key: String) -> (Pager, PagerWorker) {
+fn build_rootly_pager(builder: PagerBuilder, api_key: String) -> (Pager, PagerWorker) {
   let mut rootly_builder = builder
       .rootly(RootlyApiKey::new(api_key));
 

crates/service/web/storyteller_web/src/state/flags/mod.rs

@@ -0,0 +1 @@
+pub mod paging_flags;

crates/service/web/storyteller_web/src/state/flags/paging_flags.rs

@@ -0,0 +1,21 @@
+/// Flags controlling the pager system.
+#[derive(Clone, Debug)]
+pub struct PagingFlags {
+  /// Master switch for paging. If false, no pages are sent.
+  /// Env var: ENABLE_PAGING (default: false)
+  pub is_paging_enabled: bool,
+
+  /// If true, the error alerting middleware will enqueue pages for HTTP 500s.
+  /// Requires `is_paging_enabled` to also be true.
+  /// Env var: ENABLE_PAGING_FOR_500S (default: false)
+  pub is_paging_for_500s_enabled: bool,
+}
+
+impl PagingFlags {
+  pub fn from_env() -> Self {
+    Self {
+      is_paging_enabled: easyenv::get_env_bool_or_default("ENABLE_PAGING", false),
+      is_paging_for_500s_enabled: easyenv::get_env_bool_or_default("ENABLE_PAGING_FOR_500S", false),
+    }
+  }
+}

crates/service/web/storyteller_web/src/state/mod.rs

@@ -1,4 +1,5 @@
 pub mod cached_queries;
+pub mod flags;
 pub mod certs;
 pub mod memory_cache;
 pub mod server_state;

crates/service/web/storyteller_web/src/state/server_state.rs

@@ -33,6 +33,7 @@ use crate::http_server::endpoints::stats::result_transformer::CacheableQueueStat
 use crate::http_server::endpoints::tts::list_tts_models::TtsModelRecordForResponse;
 use crate::http_server::endpoints::voice_conversion::list_voice_conversion_models_handler::VoiceConversionModel;
 use crate::http_server::session::session_checker::SessionChecker;
+use crate::state::flags::paging_flags::PagingFlags;
 use crate::http_server::web_utils::redis_rate_limiter::RedisRateLimiter;
 use crate::http_server::web_utils::scoped_temp_dir_creator::ScopedTempDirCreator;
 use crate::state::certs::google_sign_in_cert::GoogleSignInCert;
@@ -298,6 +299,9 @@ pub struct StaticFeatureFlags {
   /// Disable voice conversion endpoints
   /// If true, respond with 429.
   pub disable_voice_conversion: bool,
+
+  /// Paging system flags.
+  pub paging: PagingFlags,
 }
 
 /// Instead of top level service denial, these are bans against entities that instead return