feat(common): improve how responses are attested to and finalized

common/src/indexer_service/http/indexer_service.rs

@@ -2,7 +2,8 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use std::{
-    collections::HashMap, fmt::Debug, net::SocketAddr, path::PathBuf, sync::Arc, time::Duration,
+    collections::HashMap, error::Error, fmt::Debug, net::SocketAddr, path::PathBuf, sync::Arc,
+    time::Duration,
 };
 
 use alloy_primitives::Address;
@@ -22,7 +23,7 @@ use eventuals::Eventual;
 use reqwest::StatusCode;
 use serde::{de::DeserializeOwned, Serialize};
 use sqlx::postgres::PgPoolOptions;
-use thegraph::types::DeploymentId;
+use thegraph::types::{Attestation, DeploymentId};
 use thiserror::Error;
 use tokio::signal;
 use tower::ServiceBuilder;
@@ -40,15 +41,20 @@ use crate::{
 
 use super::{request_handler::request_handler, IndexerServiceConfig};
 
-pub trait IsAttestable {
+pub trait IndexerServiceResponse {
+    type Data: IntoResponse;
+    type Error: Error;
+
     fn is_attestable(&self) -> bool;
+    fn as_str<'a>(&'a self) -> Result<&'a str, Self::Error>;
+    fn finalize(self, attestation: Option<Attestation>) -> Self::Data;
 }
 
 #[async_trait]
 pub trait IndexerServiceImpl {
     type Error: std::error::Error;
     type Request: DeserializeOwned + Send + Debug + Serialize;
-    type Response: IntoResponse + Serialize + IsAttestable;
+    type Response: IndexerServiceResponse + Sized;
     type State: Send + Sync;
 
     async fn process_request(

common/src/indexer_service/http/mod.rs

@@ -12,5 +12,6 @@ pub use config::{
     SubgraphConfig,
 };
 pub use indexer_service::{
-    IndexerService, IndexerServiceImpl, IndexerServiceOptions, IndexerServiceRelease, IsAttestable,
+    IndexerService, IndexerServiceImpl, IndexerServiceOptions, IndexerServiceRelease,
+    IndexerServiceResponse,
 };

common/src/indexer_service/http/request_handler.rs

@@ -12,7 +12,7 @@ use axum::{
 };
 use reqwest::StatusCode;
 use thegraph::types::DeploymentId;
-use tracing::{info, warn};
+use tracing::trace;
 
 use crate::{indexer_service::http::IndexerServiceResponse, prelude::AttestationSigner};
 
@@ -33,7 +33,7 @@ pub async fn request_handler<I>(
 where
     I: IndexerServiceImpl + Sync + Send + 'static,
 {
-    info!("Handling request for deployment `{manifest_id}`");
+    trace!("Handling request for deployment `{manifest_id}`");
 
     state
         .metrics
@@ -96,20 +96,14 @@ where
         (true, Some(signer)) => {
             let req = serde_json::to_string(&request)
                 .map_err(|_| IndexerServiceError::FailedToSignAttestation)?;
-            let res = serde_json::to_string(&response)
+            let res = response
+                .as_str()
                 .map_err(|_| IndexerServiceError::FailedToSignAttestation)?;
             Some(signer.create_attestation(&req, &res))
         }
     };
 
-    let mut headers = HeaderMap::new();
-    if let Some(attestation) = attestation {
-        let raw_attestation = serde_json::to_string(&attestation)
-            .map_err(|_| IndexerServiceError::FailedToProvideAttestation)?;
-        let header_value = HeaderValue::from_str(&raw_attestation)
-            .map_err(|_| IndexerServiceError::FailedToProvideAttestation)?;
-        headers.insert("graph-attestation", header_value);
-    }
+    let response = response.finalize(attestation);
 
-    Ok((StatusCode::OK, headers, response))
+    Ok((StatusCode::OK, response))
 }