feat: Introduce retry mechanism for Email notifier (#282)

Author: isSerge

Cargo.lock

@@ -21,6 +21,7 @@ actix-web = "4"
 alloy = { version = "0.15.6", features = ["full"] }
 anyhow = { version = "1.0.97", features = ["std"] }
 async-trait = "0.1"
+backon = "1.5.1"
 base64 = "0.22"
 byte-unit = "5.1.6"
 chrono = "0.4"
@@ -34,7 +35,7 @@ glob = "0.3"
 hex = "0.4"
 hmac = "0.12.0"
 lazy_static = "1.5"
-lettre = "0.11.11"
+lettre = { version = "0.11.11", features = ["tokio1", "tokio1-native-tls"] }
 libc = "0.2"
 log = "0.4"
 oz-keystore = "0.1.4"

Cargo.toml

@@ -246,6 +246,7 @@ Following notification protocols support retry policies:
 * Discord
 * Telegram
 * Webhook
+* Email
 
 Default retry policy is using exponential backoff with the following parameters:
 [cols="1,1,1"]
@@ -258,7 +259,7 @@ Default retry policy is using exponential backoff with the following parameters:
 | `jitter` | `Full` | Jitter strategy to apply to the backoff duration, currently supports `Full` and `None`
 |===
 
-These parameters can be overridden by providing custom `HttpRetryConfig` struct in `retry_policy` field in trigger configuration.
+These parameters can be overridden by providing custom `RetryConfig` struct in `retry_policy` field in trigger configuration.
 
 ===== Script Security
 

docs/modules/ROOT/pages/index.adoc

@@ -111,7 +111,7 @@ This middleware handles:
 
 * Automatic retries for transient HTTP errors (e.g., 5xx server errors, network timeouts) for requests made to the *currently active RPC URL*.
 * An exponential backoff policy between these retry attempts.
-* Parameters like the number of retries, backoff durations, and jitter are defined in an `HttpRetryConfig` struct (see <<Configuration Options>>).
+* Parameters like the number of retries, backoff durations, and jitter are defined in an `RetryConfig` struct (see <<Configuration Options>>).
 * This same-endpoint retry mechanism is independent of, and operates before, the endpoint rotation logic. If all same-endpoint retries fail for the current URL, the error is then processed by the `EndpointManager`.
 
 ==== Endpoint Rotation (via `EndpointManager`)
@@ -120,26 +120,26 @@ If all same-endpoint retries fail for the currently active RPC URL, or if certai
 
 ==== Configuration Options
 
-The same-endpoint retry behavior is configured via the `HttpRetryConfig` struct, which is used by `create_retryable_http_client` to set up the `ExponentialBackoff` policy for `reqwest-retry`.
+The same-endpoint retry behavior is configured via the `RetryConfig` struct, which is used by `create_retryable_http_client` to set up the `ExponentialBackoff` policy for `reqwest-retry`.
 
-The default settings for `HttpRetryConfig` result in an `ExponentialBackoff` policy approximately equivalent to:
+The default settings for `RetryConfig` result in an `ExponentialBackoff` policy approximately equivalent to:
 [source,rust]
 ----
-// This illustrates the default policy created by HttpRetryConfig::default()
+// This illustrates the default policy created by RetryConfig::default()
 // and create_retryable_http_client.
-let http_retry_config = HttpRetryConfig::default();
+let http_retry_config = RetryConfig::default();
 let retry_policy = ExponentialBackoff::builder()
   .base(http_retry_config.base_for_backoff)
   .retry_bounds(http_retry_config.initial_backoff, http_retry_config.max_backoff)
   .jitter(http_retry_config.jitter)
   .build_with_max_retries(http_retry_config.max_retries);
 ----
 
-The configurable options are defined in the `HttpRetryConfig` struct:
+The configurable options are defined in the `RetryConfig` struct:
 [source,rust]
 ----
 // In utils::http
-pub struct HttpRetryConfig {
+pub struct RetryConfig {
     /// Maximum number of retries for transient errors (after the initial attempt).
     pub max_retries: u32,
     /// Initial backoff duration before the first retry.
@@ -156,7 +156,7 @@ pub struct HttpRetryConfig {
 The client architecture ensures efficient resource use and consistent retry behavior:
 
 1. A single base `reqwest::Client` is created by `HttpTransportClient` with optimized connection pool settings. This base client is shared.
-2. The `create_retryable_http_client` utility takes this base client and an `HttpRetryConfig` to produce a `ClientWithMiddleware`.
+2. The `create_retryable_http_client` utility takes this base client and an `RetryConfig` to produce a `ClientWithMiddleware`.
 3. This `ClientWithMiddleware` (the "retryable client") is then used for all HTTP operations within `HttpTransportClient`, including initial health checks, requests sent via `EndpointManager`, and `try_connect` calls during rotation. This ensures all operations benefit from the configured retry policy and the shared connection pool.
 
 Each transport client may define its own retry policy:
@@ -172,7 +172,7 @@ pub struct HttpTransportClient {
 
 // Example of client creation with retry mechanism
 // Use default retry policy
-let http_retry_config = HttpRetryConfig::default();
+let http_retry_config = RetryConfig::default();
 
 // Create the base HTTP client
 let base_http_client = reqwest::ClientBuilder::new()

docs/modules/ROOT/pages/rpc.adoc

@@ -295,6 +295,7 @@ impl ConfigLoader for Trigger {
 					message,
 					sender,
 					recipients,
+					retry_policy: _,
 				} = &self.config
 				{
 					// Validate host
@@ -703,7 +704,7 @@ mod tests {
 	use crate::models::NotificationMessage;
 	use crate::models::{core::Trigger, ScriptLanguage, SecretString};
 	use crate::utils::tests::builders::trigger::TriggerBuilder;
-	use crate::utils::HttpRetryConfig;
+	use crate::utils::RetryConfig;
 	use std::{fs::File, io::Write, os::unix::fs::PermissionsExt};
 	use tempfile::TempDir;
 	use tracing_test::traced_test;
@@ -1446,7 +1447,7 @@ mod tests {
 					title: "Test".to_string(),
 					body: "x".repeat(TELEGRAM_MAX_BODY_LENGTH + 1), // Exceeds max length
 				},
-				retry_policy: HttpRetryConfig::default(),
+				retry_policy: RetryConfig::default(),
 			},
 		};
 		assert!(max_body_length.validate().is_err());
@@ -1465,7 +1466,7 @@ mod tests {
 					title: "Test".to_string(),
 					body: "z".repeat(DISCORD_MAX_BODY_LENGTH + 1), // Exceeds max length
 				},
-				retry_policy: HttpRetryConfig::default(),
+				retry_policy: RetryConfig::default(),
 			},
 		};
 		assert!(max_body_length.validate().is_err());

src/models/config/trigger_config.rs

@@ -1,6 +1,6 @@
 use crate::{
 	models::{core::ScriptLanguage, SecretValue},
-	utils::HttpRetryConfig,
+	utils::RetryConfig,
 };
 use email_address::EmailAddress;
 use serde::{Deserialize, Serialize};
@@ -61,7 +61,7 @@ pub enum TriggerTypeConfig {
 		message: NotificationMessage,
 		/// Retry policy for HTTP requests
 		#[serde(default)]
-		retry_policy: HttpRetryConfig,
+		retry_policy: RetryConfig,
 	},
 	/// Email notification configuration
 	Email {
@@ -79,6 +79,9 @@ pub enum TriggerTypeConfig {
 		sender: EmailAddress,
 		/// Email recipients
 		recipients: Vec<EmailAddress>,
+		/// Retry policy for SMTP requests
+		#[serde(default)]
+		retry_policy: RetryConfig,
 	},
 	/// Webhook configuration
 	Webhook {
@@ -94,7 +97,7 @@ pub enum TriggerTypeConfig {
 		message: NotificationMessage,
 		/// Retry policy for HTTP requests
 		#[serde(default)]
-		retry_policy: HttpRetryConfig,
+		retry_policy: RetryConfig,
 	},
 	/// Telegram notification configuration
 	Telegram {
@@ -108,7 +111,7 @@ pub enum TriggerTypeConfig {
 		message: NotificationMessage,
 		/// Retry policy for HTTP requests
 		#[serde(default)]
-		retry_policy: HttpRetryConfig,
+		retry_policy: RetryConfig,
 	},
 	/// Discord notification configuration
 	Discord {
@@ -118,7 +121,7 @@ pub enum TriggerTypeConfig {
 		message: NotificationMessage,
 		/// Retry policy for HTTP requests
 		#[serde(default)]
-		retry_policy: HttpRetryConfig,
+		retry_policy: RetryConfig,
 	},
 	/// Script execution configuration
 	Script {
@@ -136,7 +139,7 @@ pub enum TriggerTypeConfig {
 
 impl TriggerTypeConfig {
 	/// Get the retry policy for the trigger type, if applicable.
-	pub fn get_retry_policy(&self) -> Option<HttpRetryConfig> {
+	pub fn get_retry_policy(&self) -> Option<RetryConfig> {
 		match self {
 			Self::Slack { retry_policy, .. } => Some(retry_policy.clone()),
 			Self::Discord { retry_policy, .. } => Some(retry_policy.clone()),

src/models/core/trigger.rs

@@ -22,7 +22,7 @@ use crate::{
 		BlockchainTransport, EndpointManager, RotatingTransport, TransientErrorRetryStrategy,
 		TransportError,
 	},
-	utils::http::{create_retryable_http_client, HttpRetryConfig},
+	utils::http::{create_retryable_http_client, RetryConfig},
 };
 
 /// Basic HTTP transport client for blockchain interactions
@@ -71,7 +71,7 @@ impl HttpTransportClient {
 
 		// Create a retry policy with default settings
 		// Shared config for endpoint manager and test connection
-		let http_retry_config = HttpRetryConfig::default();
+		let http_retry_config = RetryConfig::default();
 
 		// Create the base HTTP client
 		let base_http_client = Arc::new(

src/services/blockchain/transports/http.rs

@@ -185,7 +185,7 @@ impl Notifier for DiscordNotifier {
 mod tests {
 	use crate::{
 		models::{NotificationMessage, SecretString, SecretValue},
-		utils::{tests::create_test_http_client, HttpRetryConfig},
+		utils::{tests::create_test_http_client, RetryConfig},
 	};
 
 	use super::*;
@@ -209,7 +209,7 @@ mod tests {
 				title: "Test Alert".to_string(),
 				body: "Test message ${value}".to_string(),
 			},
-			retry_policy: HttpRetryConfig::default(),
+			retry_policy: RetryConfig::default(),
 		}
 	}