refactor: Add throttle as a global config

Makefile

@@ -0,0 +1,18 @@
+# Run the backend without worker mode, i.e. only enabling single-shot
+# verifications via the /v1/check_email endpoint.
+.PHONY: run
+run:
+	cd backend && cargo run --bin reacher_backend
+
+
+# Run the backend with worker mode on. This enables the /v1/bulk endpoints.
+# Make sure to have a Postgres DB and a RabbitMQ instance running.
+.PHONY: run-with-worker
+run-with-worker: export RCH__WORKER__ENABLE=true
+run-with-worker: export RCH__WORKER__RABBITMQ__URL=amqp://guest:guest@localhost:5672
+run-with-worker: export RCH__STORAGE__POSTGRES__DB_URL=postgresql://localhost/reacherdb
+run-with-worker: run
+
+.PHONY: run-with-commercial-license-trial
+run-with-commercial-license-trial: export RCH__COMMERCIAL_LICENSE_TRIAL__URL=http://localhost:3000/api/v1/commercial_license_trial
+run-with-commercial-license-trial: run

backend/backend_config.toml

@@ -88,12 +88,47 @@ hotmailb2c = "headless"
 # recommended.
 yahoo = "headless"
 
+# Throttle the maximum number of requests per second, per minute, per hour, and
+# per day for this worker.
+# All fields are optional; comment them out to disable the limit.
+#
+# We however recommend setting the throttle for at least the per-minute and
+# per-day limits to prevent the IPs from being blocked by the email providers.
+# The default values are set to 60 requests per minute and 10,000 requests per
+# day.
+#
+# Important: these throttle configurations only apply to /v1/* endpoints, and
+# not to the previous /v0/check_email endpoint. The latter endpoint always
+# executes the verification immediately, regardless of the throttle settings.
+#
+# Env variables:
+# - RCH__THROTTLE__MAX_REQUESTS_PER_SECOND
+# - RCH__THROTTLE__MAX_REQUESTS_PER_MINUTE
+# - RCH__THROTTLE__MAX_REQUESTS_PER_HOUR
+# - RCH__THROTTLE__MAX_REQUESTS_PER_DAY
+[throttle]
+# max_requests_per_second = 20
+max_requests_per_minute = 60
+# max_requests_per_hour = 1000
+max_requests_per_day = 10000
+
+# Configuration for a queue-based architecture for Reacher. This feature is
+# currently in **beta**. The queue-based architecture allows Reacher to scale
+# horizontally by running multiple workers that consume emails from a RabbitMQ
+# queue.
+#
+# To enable the queue-based architecture, set the "enable" field to "true" and
+# configure the RabbitMQ connection below. The "concurrency" field specifies
+# the number of concurrent emails to verify for this worker.
+#
+# For more information, see the documentation at:
+# https://docs.reacher.email/self-hosting/scaling-for-production
 [worker]
 # Enable the worker to consume emails from the RabbitMQ queues. If set, the
 # RabbitMQ configuration below must be set as well.
 #
 # Env variable: RCH__WORKER__ENABLE
-enable = true
+enable = false
 
 # RabbitMQ configuration.
 [worker.rabbitmq]
@@ -105,25 +140,6 @@ url = "amqp://guest:guest@localhost:5672"
 # Env variable: RCH__WORKER__RABBITMQ__CONCURRENCY
 concurrency = 5
 
-# Throttle the maximum number of requests per second, per minute, per hour, and
-# per day for this worker.
-# All fields are optional; comment them out to disable the limit.
-#
-# Important: these throttle configurations only apply to /v1/* endpoints, and
-# not to the previous /v0/check_email endpoint. The latter endpoint always
-# executes the verification immediately, regardless of the throttle settings.
-#
-# Env variables:
-# - RCH__WORKER__THROTTLE__MAX_REQUESTS_PER_SECOND
-# - RCH__WORKER__THROTTLE__MAX_REQUESTS_PER_MINUTE
-# - RCH__WORKER__THROTTLE__MAX_REQUESTS_PER_HOUR
-# - RCH__WORKER__THROTTLE__MAX_REQUESTS_PER_DAY
-[worker.throttle]
-# max_requests_per_second = 20
-# max_requests_per_minute = 100
-# max_requests_per_hour = 1000
-# max_requests_per_day = 20000
-
 # Below are the configurations for the storage of the email verification
 # results. We currently support the following storage backends:
 # - Postgres

backend/openapi.json

@@ -702,7 +702,7 @@
 					"duration": {
 						"$ref": "#/components/schemas/Duration"
 					},
-					"server_name": {
+					"backend_name": {
 						"type": "string",
 						"x-stoplight": {
 							"id": "2jrbdecvqh4t5"
@@ -717,7 +717,7 @@
 					"start_time",
 					"end_time",
 					"duration",
-					"server_name",
+					"backend_name",
 					"smtp"
 				]
 			},

backend/src/config.rs

@@ -15,6 +15,7 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 use crate::storage::{postgres::PostgresStorage, StorageAdapter};
+use crate::throttle::ThrottleManager;
 use crate::worker::do_work::TaskWebhook;
 use crate::worker::setup_rabbit_mq;
 use anyhow::{bail, Context};
@@ -29,7 +30,7 @@ use sqlx::PgPool;
 use std::sync::Arc;
 use tracing::warn;
 
-#[derive(Debug, Default, Serialize, Deserialize)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct BackendConfig {
 	/// Name of the backend.
 	pub backend_name: String,
@@ -65,36 +66,61 @@ pub struct BackendConfig {
 	/// Whether to enable the Commercial License Trial. Setting this to true
 	pub commercial_license_trial: Option<CommercialLicenseTrialConfig>,
 
+	/// Throttle configuration for all requests
+	pub throttle: ThrottleConfig,
+
 	// Internal fields, not part of the configuration.
 	#[serde(skip)]
 	channel: Option<Arc<Channel>>,
 
 	#[serde(skip)]
 	storage_adapter: Arc<StorageAdapter>,
+
+	#[serde(skip)]
+	throttle_manager: Arc<ThrottleManager>,
 }
 
 impl BackendConfig {
+	/// Create an empty BackendConfig. This is useful for testing purposes.
+	pub fn empty() -> Self {
+		Self {
+			backend_name: "".to_string(),
+			from_email: "".to_string(),
+			hello_name: "".to_string(),
+			webdriver_addr: "".to_string(),
+			proxy: None,
+			verif_method: VerifMethodConfig::default(),
+			http_host: "127.0.0.1".to_string(),
+			http_port: 8080,
+			header_secret: None,
+			smtp_timeout: None,
+			sentry_dsn: None,
+			worker: WorkerConfig::default(),
+			storage: Some(StorageConfig::Noop),
+			commercial_license_trial: None,
+			throttle: ThrottleConfig::new_without_throttle(),
+			channel: None,
+			storage_adapter: Arc::new(StorageAdapter::Noop),
+			throttle_manager: Arc::new(
+				ThrottleManager::new(ThrottleConfig::new_without_throttle()),
+			),
+		}
+	}
+
 	/// Get the worker configuration.
 	///
 	/// # Panics
 	///
 	/// Panics if the worker configuration is missing.
 	pub fn must_worker_config(&self) -> Result<MustWorkerConfig, anyhow::Error> {
-		match (
-			self.worker.enable,
-			&self.worker.throttle,
-			&self.worker.rabbitmq,
-			&self.channel,
-		) {
-			(true, Some(throttle), Some(rabbitmq), Some(channel)) => Ok(MustWorkerConfig {
+		match (self.worker.enable, &self.worker.rabbitmq, &self.channel) {
+			(true, Some(rabbitmq), Some(channel)) => Ok(MustWorkerConfig {
 				channel: channel.clone(),
-				throttle: throttle.clone(),
 				rabbitmq: rabbitmq.clone(),
-
 				webhook: self.worker.webhook.clone(),
 			}),
 
-			(true, _, _, _) => bail!("Worker configuration is missing"),
+			(true, _, _) => bail!("Worker configuration is missing"),
 			_ => bail!("Calling must_worker_config on a non-worker backend"),
 		}
 	}
@@ -126,6 +152,9 @@ impl BackendConfig {
 		};
 		self.channel = channel;
 
+		// Initialize throttle manager
+		self.throttle_manager = Arc::new(ThrottleManager::new(self.throttle.clone()));
+
 		Ok(())
 	}
 
@@ -142,6 +171,10 @@ impl BackendConfig {
 			StorageAdapter::Noop => None,
 		}
 	}
+
+	pub fn get_throttle_manager(&self) -> Arc<ThrottleManager> {
+		self.throttle_manager.clone()
+	}
 }
 
 #[derive(Debug, Default, Deserialize, Clone, Serialize)]
@@ -159,9 +192,6 @@ pub struct VerifMethodConfig {
 #[derive(Debug, Default, Deserialize, Clone, Serialize)]
 pub struct WorkerConfig {
 	pub enable: bool,
-
-	/// Throttle configuration for the worker.
-	pub throttle: Option<ThrottleConfig>,
 	pub rabbitmq: Option<RabbitMQConfig>,
 	/// Optional webhook configuration to send email verification results.
 	pub webhook: Option<TaskWebhook>,
@@ -172,8 +202,6 @@ pub struct WorkerConfig {
 #[derive(Debug, Clone)]
 pub struct MustWorkerConfig {
 	pub channel: Arc<Channel>,
-
-	pub throttle: ThrottleConfig,
 	pub rabbitmq: RabbitMQConfig,
 	pub webhook: Option<TaskWebhook>,
 }
@@ -185,7 +213,7 @@ pub struct RabbitMQConfig {
 	pub concurrency: u16,
 }
 
-#[derive(Debug, Deserialize, Clone, Serialize)]
+#[derive(Debug, Default, Deserialize, Clone, Serialize)]
 pub struct ThrottleConfig {
 	pub max_requests_per_second: Option<u32>,
 	pub max_requests_per_minute: Option<u32>,
@@ -236,8 +264,13 @@ pub async fn load_config() -> Result<BackendConfig, anyhow::Error> {
 
 	let cfg = cfg.build()?.try_deserialize::<BackendConfig>()?;
 
-	if !cfg.worker.enable && (cfg.worker.rabbitmq.is_some() || cfg.worker.throttle.is_some()) {
-		warn!(target: LOG_TARGET, "worker.enable is set to false, ignoring throttling and concurrency settings.")
+	if cfg.worker.enable {
+		warn!(target: LOG_TARGET, "The worker feature is currently in beta. Please send any feedback to [email protected].");
+
+		match &cfg.storage {
+			Some(StorageConfig::Postgres(_)) => {}
+			_ => bail!("When worker mode is enabled, a Postgres database must be configured."),
+		}
 	}
 
 	Ok(cfg)

backend/src/http/error.rs

@@ -28,7 +28,7 @@ pub trait DisplayDebug: fmt::Display + Debug + Sync + Send {}
 impl<T: fmt::Display + Debug + Sync + Send> DisplayDebug for T {}
 
 /// Struct describing an error response.
-#[derive(Debug)]
+#[derive(Debug, thiserror::Error)]
 pub struct ReacherResponseError {
 	pub code: StatusCode,
 	pub error: Box<dyn DisplayDebug>,
@@ -121,7 +121,14 @@ impl From<StorageError> for ReacherResponseError {
 
 impl From<reqwest::Error> for ReacherResponseError {
 	fn from(e: reqwest::Error) -> Self {
-		ReacherResponseError::new(StatusCode::INTERNAL_SERVER_ERROR, e)
+		ReacherResponseError::new(
+			e.status()
+				.map(|s| s.as_u16())
+				.map(StatusCode::from_u16)
+				.and_then(Result::ok)
+				.unwrap_or(StatusCode::INTERNAL_SERVER_ERROR),
+			e,
+		)
 	}
 }
 

backend/src/http/mod.rs

@@ -23,14 +23,12 @@ use crate::config::BackendConfig;
 use check_if_email_exists::LOG_TARGET;
 use error::handle_rejection;
 pub use error::ReacherResponseError;
-use sqlx::PgPool;
 use sqlxmq::JobRunnerHandle;
 use std::env;
 use std::net::IpAddr;
 use std::sync::Arc;
 use tracing::info;
 pub use v0::check_email::post::CheckEmailRequest;
-use warp::http::StatusCode;
 use warp::Filter;
 
 pub fn create_routes(
@@ -101,24 +99,6 @@ pub async fn run_warp_server(
 	Ok(runner)
 }
 
-/// Warp filter to add the database pool to the handler. If the pool is not
-/// configured, it will return an error.
-pub fn with_db(
-	pg_pool: Option<PgPool>,
-) -> impl Filter<Extract = (PgPool,), Error = warp::Rejection> + Clone {
-	warp::any().and_then(move || {
-		let pool = pg_pool.clone();
-		async move {
-			pool.ok_or_else(|| {
-				warp::reject::custom(ReacherResponseError::new(
-					StatusCode::SERVICE_UNAVAILABLE,
-					"Please configure a Postgres database on Reacher before calling this endpoint",
-				))
-			})
-		}
-	})
-}
-
 /// The header which holds the Reacher backend secret.
 pub const REACHER_SECRET_HEADER: &str = "x-reacher-secret";
 

backend/src/http/v1/bulk/get_progress.rs

@@ -25,8 +25,9 @@ use sqlx::PgPool;
 use warp::http::StatusCode;
 use warp::Filter;
 
+use super::with_worker_db;
 use crate::config::BackendConfig;
-use crate::http::{with_db, ReacherResponseError};
+use crate::http::ReacherResponseError;
 
 /// NOTE: Type conversions from postgres to rust types
 /// are according to the table given by
@@ -149,7 +150,7 @@ pub fn v1_get_bulk_job_progress(
 ) -> impl Filter<Extract = (impl warp::Reply,), Error = warp::Rejection> + Clone {
 	warp::path!("v1" / "bulk" / i32)
 		.and(warp::get())
-		.and(with_db(config.get_pg_pool()))
+		.and(with_worker_db(config))
 		.and_then(http_handler)
 		// View access logs by setting `RUST_LOG=reacher`.
 		.with(warp::log(LOG_TARGET))

backend/src/http/v1/bulk/get_results/mod.rs

@@ -25,8 +25,9 @@ use std::{convert::TryInto, sync::Arc};
 use warp::http::StatusCode;
 use warp::Filter;
 
+use super::with_worker_db;
 use crate::config::BackendConfig;
-use crate::http::{with_db, ReacherResponseError};
+use crate::http::ReacherResponseError;
 use csv_helper::{CsvResponse, CsvWrapper};
 
 mod csv_helper;
@@ -180,7 +181,7 @@ pub fn v1_get_bulk_job_results(
 ) -> impl Filter<Extract = (impl warp::Reply,), Error = warp::Rejection> + Clone {
 	warp::path!("v1" / "bulk" / i32 / "results")
 		.and(warp::get())
-		.and(with_db(config.get_pg_pool()))
+		.and(with_worker_db(config))
 		.and(warp::query::<Request>())
 		.and_then(http_handler)
 		// View access logs by setting `RUST_LOG=reacher_backend`.