draft: planner service over http

bin/gateway/src/main.rs

@@ -1,6 +1,7 @@
 mod http_utils;
 mod logger;
 mod pipeline;
+mod planner_service;
 mod shared_state;
 
 use crate::{
@@ -10,12 +11,15 @@ use crate::{
         request_id::{RequestIdGenerator, REQUEST_ID_HEADER_NAME},
     },
     logger::{configure_logging, LoggingFormat},
+    planner_service::{
+        planner_service_handler, supergraph_schema_handler, supergraph_version_handler,
+    },
     shared_state::GatewaySharedState,
 };
 use axum::{
     body::Body,
     http::Method,
-    routing::{any_service, get},
+    routing::{any_service, get, post},
     Router,
 };
 use http::Request;
@@ -78,7 +82,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         )
     });
     let parsed_schema = parse_schema(&supergraph_sdl);
-    let gateway_shared_state = GatewaySharedState::new(parsed_schema);
+    let supergraph_version = env::var("SUPERGRAPH_VERSION").unwrap_or_default();
+    let gateway_shared_state = GatewaySharedState::new(parsed_schema, supergraph_version);
 
     let pipeline = ServiceBuilder::new()
         .layer(Extension(gateway_shared_state.clone()))
@@ -115,7 +120,11 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     let app = Router::new()
         .route("/graphql", any_service(pipeline))
+        .route("/supergraph/version", get(supergraph_version_handler))
+        .route("/supergraph/schema", get(supergraph_schema_handler))
+        .route("/build-query-plan", post(planner_service_handler))
         .route("/health", get(health_check_handler))
+        .layer(Extension(gateway_shared_state.clone()))
         .layer(
             CorsLayer::new()
                 .allow_methods([Method::GET, Method::POST, Method::OPTIONS])

bin/gateway/src/planner_service.rs

@@ -0,0 +1,102 @@
+use std::{collections::HashSet, sync::Arc};
+
+use axum::{response::IntoResponse, Extension, Json};
+use graphql_tools::validation::validate::validate;
+use http::{header::CONTENT_TYPE, StatusCode};
+use query_planner::{
+    ast::{document::NormalizedDocument, normalization::normalize_operation},
+    graph::{PlannerOverrideContext, PERCENTAGE_SCALE_FACTOR},
+    planner::plan_nodes::QueryPlan,
+    utils::parsing::safe_parse_operation,
+};
+use rand::Rng;
+use serde::Deserialize;
+use sonic_rs::json;
+
+use crate::{pipeline::error::PipelineErrorVariant, shared_state::GatewaySharedState};
+
+pub async fn supergraph_version_handler(
+    state: Extension<Arc<GatewaySharedState>>,
+) -> impl IntoResponse {
+    json!({
+        "version": state.supergraph_version
+    })
+    .to_string()
+}
+
+pub async fn supergraph_schema_handler(
+    state: Extension<Arc<GatewaySharedState>>,
+) -> impl IntoResponse {
+    state.sdl.clone()
+}
+
+#[derive(Deserialize)]
+pub struct PlannerServiceJsonInput {
+    #[serde(rename = "operationName")]
+    pub operation_name: Option<String>,
+    pub query: String,
+}
+
+pub async fn planner_service_handler(
+    state: Extension<Arc<GatewaySharedState>>,
+    body: Json<PlannerServiceJsonInput>,
+) -> impl IntoResponse {
+    match plan(&body.0, &state).await {
+        Ok((plan, normalized_document)) => (
+            StatusCode::OK,
+            [(CONTENT_TYPE, "application/json")],
+            json!({
+                "plan": plan,
+                "normalizedOperation": normalized_document.operation.to_string()
+            })
+            .to_string(),
+        ),
+        Err(err) => (
+            err.default_status_code(false),
+            [(CONTENT_TYPE, "application/json")],
+            json!({
+                "error": err.graphql_error_message()
+            })
+            .to_string(),
+        ),
+    }
+}
+
+async fn plan(
+    input: &PlannerServiceJsonInput,
+    state: &GatewaySharedState,
+) -> Result<(QueryPlan, NormalizedDocument), PipelineErrorVariant> {
+    let parsed_operation =
+        safe_parse_operation(&input.query).map_err(PipelineErrorVariant::FailedToParseOperation)?;
+    let consumer_schema_ast = &state.planner.consumer_schema.document;
+    let validation_errors = validate(
+        consumer_schema_ast,
+        &parsed_operation,
+        &state.validation_plan,
+    );
+
+    if !validation_errors.is_empty() {
+        return Err(PipelineErrorVariant::ValidationErrors(Arc::new(
+            validation_errors,
+        )));
+    }
+
+    let normalized_operation = normalize_operation(
+        &state.planner.supergraph,
+        &parsed_operation,
+        input.operation_name.as_deref(),
+    )
+    .map_err(PipelineErrorVariant::NormalizationError)?;
+
+    let request_override_context = PlannerOverrideContext::new(
+        HashSet::new(),
+        rand::rng().random_range(0..=(100 * PERCENTAGE_SCALE_FACTOR)),
+    );
+
+    let plan = state
+        .planner
+        .plan_from_normalized_operation(&normalized_operation.operation, request_override_context)
+        .map_err(PipelineErrorVariant::PlannerError)?;
+
+    Ok((plan, normalized_operation))
+}

bin/gateway/src/shared_state.rs

@@ -25,10 +25,15 @@ pub struct GatewaySharedState {
     pub validate_cache: Cache<u64, Arc<Vec<ValidationError>>>,
     pub parse_cache: Cache<u64, Arc<graphql_parser::query::Document<'static, String>>>,
     pub normalize_cache: Cache<u64, Arc<GraphQLNormalizationPayload>>,
+    pub supergraph_version: String,
+    pub sdl: String,
 }
 
 impl GatewaySharedState {
-    pub fn new(parsed_supergraph_sdl: Document<'static, String>) -> Arc<Self> {
+    pub fn new(
+        parsed_supergraph_sdl: Document<'static, String>,
+        supergraph_version: String,
+    ) -> Arc<Self> {
         let supergraph_state = SupergraphState::new(&parsed_supergraph_sdl);
         let planner =
             Planner::new_from_supergraph(&parsed_supergraph_sdl).expect("failed to create planner");
@@ -52,6 +57,8 @@ impl GatewaySharedState {
             validate_cache: moka::future::Cache::new(1000),
             parse_cache: moka::future::Cache::new(1000),
             normalize_cache: moka::future::Cache::new(1000),
+            supergraph_version,
+            sdl: parsed_supergraph_sdl.to_string(),
         })
     }
 }