api: add ingress request throttling

apps/admin-api/src/error.rs

@@ -41,6 +41,11 @@ pub enum ApiError {
         context: Option<Value>,
     },
     #[error("{message}")]
+    RateLimited {
+        message: String,
+        context: Option<Value>,
+    },
+    #[error("{message}")]
     Internal {
         message: String,
         context: Option<Value>,
@@ -76,6 +81,13 @@ impl ApiError {
         }
     }
 
+    pub(crate) fn rate_limited_with_context(message: impl Into<String>, context: Value) -> Self {
+        Self::RateLimited {
+            message: message.into(),
+            context: Some(context),
+        }
+    }
+
     pub(crate) fn validation_with_context(message: impl Into<String>, context: Value) -> Self {
         Self::Validation {
             message: message.into(),
@@ -104,6 +116,7 @@ impl ApiError {
             Self::Validation { .. } => StatusCode::BAD_REQUEST,
             Self::NotFound { .. } => StatusCode::NOT_FOUND,
             Self::Conflict { .. } => StatusCode::CONFLICT,
+            Self::RateLimited { .. } => StatusCode::TOO_MANY_REQUESTS,
             Self::Internal { .. } => StatusCode::INTERNAL_SERVER_ERROR,
         }
     }
@@ -115,6 +128,7 @@ impl ApiError {
             Self::Validation { .. } => "validation_error",
             Self::NotFound { .. } => "not_found",
             Self::Conflict { .. } => "conflict",
+            Self::RateLimited { .. } => "rate_limited",
             Self::Internal { .. } => "internal_error",
         }
     }
@@ -130,7 +144,8 @@ impl IntoResponse for ApiError {
             | Self::Forbidden { message, .. }
             | Self::Validation { message, .. }
             | Self::NotFound { message, .. }
-            | Self::Conflict { message, .. } => {
+            | Self::Conflict { message, .. }
+            | Self::RateLimited { message, .. } => {
                 warn!(error_code = self.code(), error_message = %message)
             }
         }
@@ -159,6 +174,7 @@ impl ApiError {
             | Self::Validation { context, .. }
             | Self::NotFound { context, .. }
             | Self::Conflict { context, .. }
+            | Self::RateLimited { context, .. }
             | Self::Internal { context, .. } => context.clone(),
         }
     }