Implement Ingress Service

src/ingress_grpc/Cargo.toml

@@ -52,6 +52,7 @@ drain = { workspace = true }
 arc-swap = { workspace = true }
 thiserror = { workspace = true }
 schemars = { workspace = true, optional = true }
+once_cell = "1.18"
 
 [dev-dependencies]
 hyper = { workspace = true, features = ["client"] }

src/ingress_grpc/build.rs

@@ -12,9 +12,14 @@ fn main() -> std::io::Result<()> {
         .compile_protos(
             &[
                 "proto/grpc/reflection/v1alpha/reflection.proto",
+                "proto/dev/restate/services.proto",
                 "tests/proto/greeter.proto",
             ],
-            &["proto/grpc/reflection/v1alpha", "tests/proto"],
+            &[
+                "proto/grpc/reflection/v1alpha",
+                "proto/dev/restate",
+                "tests/proto",
+            ],
         )?;
     Ok(())
 }

src/ingress_grpc/proto/dev/restate/services.proto

@@ -0,0 +1,35 @@
+/*
+  This package provides interfaces for built-in services
+ */
+syntax = "proto3";
+
+package dev.restate;
+
+option java_multiple_files = true;
+option java_package = "dev.restate.generated";
+option go_package = "restate.dev/sdk-go/pb";
+
+service Ingress {
+  // Invoke a service and don't wait for the response.
+  // It is guaranteed that the service will be invoked after this method returns.
+  rpc Invoke(InvokeRequest) returns (InvokeResponse);
+}
+
+message InvokeRequest {
+  // Fully qualified name of the service, e.g. `counter.Counter`
+  string service = 1;
+  // Method name of the service to invoke, e.g. `Add`
+  string method = 2;
+  // Argument of the invocation.
+  // When executing requests to the ingress using Protobuf,
+  // this field must contain the serialized Protobuf matching the argument type of the target method.
+  // When executing requests to the ingress using JSON,
+  // this field must contain the JSON object representing the argument type of the target method.
+  bytes argument = 3;
+}
+
+message InvokeResponse {
+  // Generated unique invocation identifier.
+  // It can be used to retrieve the status of the invocation and cancel it.
+  string sid = 1;
+}

src/ingress_grpc/src/handler.rs

@@ -1,6 +1,8 @@
 use super::options::JsonOptions;
+use super::pb::grpc::reflection::{
+    server_reflection_server::ServerReflection, server_reflection_server::ServerReflectionServer,
+};
 use super::protocol::{BoxBody, Protocol};
-use super::reflection::{ServerReflection, ServerReflectionServer};
 use super::*;
 
 use std::sync::Arc;
@@ -12,6 +14,7 @@ use http::{Request, Response, StatusCode};
 use http_body::Body;
 use hyper::Body as HyperBody;
 use opentelemetry::trace::{SpanContext, TraceContextExt};
+use prost::Message;
 use restate_common::types::{IngressId, ServiceInvocationResponseSink, SpanRelation};
 use restate_service_metadata::MethodDescriptorRegistry;
 use tokio::sync::Semaphore;
@@ -87,7 +90,7 @@ impl<InvocationFactory, MethodRegistry, ReflectionService> Service<Request<Hyper
     for Handler<InvocationFactory, MethodRegistry, ReflectionService>
 where
     InvocationFactory: ServiceInvocationFactory + Clone + Send + 'static,
-    MethodRegistry: MethodDescriptorRegistry,
+    MethodRegistry: MethodDescriptorRegistry + Clone + Send + 'static,
     ReflectionService: ServerReflection,
 {
     type Response = Response<BoxBody>;
@@ -144,6 +147,8 @@ where
         let method_name = path_parts.remove(2).to_string();
         let service_name = path_parts.remove(1).to_string();
 
+        // --- Special Restate services
+        // Reflections
         if ServerReflectionServer::<ReflectionService>::NAME == service_name {
             return self
                 .reflection_server
@@ -155,20 +160,6 @@ where
                 .boxed();
         }
 
-        // Find the service method descriptor
-        let descriptor = if let Some(desc) = self
-            .method_registry
-            .resolve_method_descriptor(&service_name, &method_name)
-        {
-            desc
-        } else {
-            debug!("{}/{} not found", service_name, method_name);
-            return ok(protocol.encode_status(Status::not_found(format!(
-                "{service_name}/{method_name} not found"
-            ))))
-            .boxed();
-        };
-
         // Encapsulate in this closure the remaining part of the processing
         let ingress_id = self.ingress_id;
         let invocation_factory = self.invocation_factory.clone();
@@ -197,12 +188,30 @@ where
             let ingress_span_context = ingress_span.context().span().span_context().clone();
 
             async move {
+                let mut service_name = req_headers.service_name;
+                let mut method_name = req_headers.method_name;
+                let mut req_payload = req_payload;
+                let mut response_sink = Some(ServiceInvocationResponseSink::Ingress(ingress_id));
+                let mut wait_response = true;
+
+                // Ingress built-in service
+                if is_ingress_invoke(&service_name, &method_name) {
+                    let invoke_request = pb::restate::services::InvokeRequest::decode(req_payload)
+                        .map_err(|e| Status::invalid_argument(e.to_string()))?;
+
+                    service_name = invoke_request.service;
+                    method_name = invoke_request.method;
+                    req_payload = invoke_request.argument;
+                    response_sink = None;
+                    wait_response = false;
+                }
+
                 // Create the service_invocation
                 let (service_invocation, service_invocation_span) = match invocation_factory.create(
-                    &req_headers.service_name,
-                    &req_headers.method_name,
+                    &service_name,
+                    &method_name,
                     req_payload,
-                    Some(ServiceInvocationResponseSink::Ingress(ingress_id)),
+                    response_sink,
                     SpanRelation::Parent(ingress_span_context)
                 ) {
                     Ok(i) => i,
@@ -222,8 +231,22 @@ where
                 // https://docs.rs/tracing/latest/tracing/struct.Span.html#in-asynchronous-code
                 let enter_service_invocation_span = service_invocation_span.enter();
 
-                // More trace info
-                trace!(restate.invocation.request_headers = ?req_headers);
+                // Ingress built-in service just sends a fire and forget and closes
+                if !wait_response {
+                    let sid = service_invocation.id.to_string();
+
+                    if dispatcher_command_sender.send(Command::fire_and_forget(
+                        service_invocation
+                    )).is_err() {
+                        debug!("Ingress dispatcher is closed while there is still an invocation in flight.");
+                        return Err(Status::unavailable("Unavailable"));
+                    }
+                    return Ok(
+                        pb::restate::services::InvokeResponse {
+                            sid,
+                        }.encode_to_vec().into()
+                    )
+                }
 
                 // Send the service invocation
                 let (service_invocation_command, response_rx) =
@@ -259,7 +282,7 @@ where
         let result_fut = protocol.handle_request(
             service_name,
             method_name,
-            descriptor,
+            self.method_registry.clone(),
             self.json.clone(),
             req,
             ingress_request_handler,
@@ -283,3 +306,7 @@ fn span_relation(request_span: &SpanContext) -> SpanRelation {
         SpanRelation::None
     }
 }
+
+fn is_ingress_invoke(service_name: &str, method_name: &str) -> bool {
+    "dev.restate.Ingress" == service_name && "Invoke" == method_name
+}

src/ingress_grpc/src/lib.rs

@@ -1,12 +1,14 @@
 mod dispatcher;
 mod handler;
 mod options;
+mod pb;
 mod protocol;
 mod reflection;
 mod server;
 
 pub use dispatcher::{IngressDispatcherLoop, IngressDispatcherLoopError};
 pub use options::Options;
+pub use pb::MethodDescriptorRegistryWithIngressService;
 pub use reflection::{ReflectionRegistry, RegistrationError};
 pub use server::{HyperServerIngress, IngressServerError, StartSignal};
 
@@ -203,9 +205,23 @@ mod mocks {
     pub(super) fn test_descriptor_registry() -> InMemoryMethodDescriptorRegistry {
         let registry = InMemoryMethodDescriptorRegistry::default();
         registry.register(greeter_service_descriptor());
+        registry.register(ingress_service_descriptor());
         registry
     }
 
+    pub(super) fn ingress_service_descriptor() -> ServiceDescriptor {
+        crate::pb::DEV_RESTATE_DESCRIPTOR_POOL
+            .get_service_by_name("dev.restate.Ingress")
+            .unwrap()
+    }
+
+    pub(super) fn ingress_invoke_method_descriptor() -> MethodDescriptor {
+        ingress_service_descriptor()
+            .methods()
+            .find(|m| m.name() == "Invoke")
+            .unwrap()
+    }
+
     pub(super) fn greeter_service_descriptor() -> ServiceDescriptor {
         test_descriptor_pool()
             .services()

src/ingress_grpc/src/options.rs

@@ -1,7 +1,8 @@
-use super::reflection::ServerReflection;
+use super::pb::grpc::reflection::server_reflection_server::ServerReflection;
 use super::HyperServerIngress;
 use super::*;
 
+use crate::pb::MethodDescriptorRegistryWithIngressService;
 use prost_reflect::{DeserializeOptions, SerializeOptions};
 use restate_common::types::IngressId;
 use restate_service_metadata::MethodDescriptorRegistry;
@@ -169,7 +170,11 @@ impl Options {
         channel_size: usize,
     ) -> (
         IngressDispatcherLoop,
-        HyperServerIngress<DescriptorRegistry, InvocationFactory, ReflectionService>,
+        HyperServerIngress<
+            MethodDescriptorRegistryWithIngressService<DescriptorRegistry>,
+            InvocationFactory,
+            ReflectionService,
+        >,
     )
     where
         DescriptorRegistry: MethodDescriptorRegistry + Clone + Send + 'static,
@@ -189,7 +194,7 @@ impl Options {
             concurrency_limit,
             json,
             ingress_id,
-            descriptor_registry,
+            MethodDescriptorRegistryWithIngressService::new(descriptor_registry),
             invocation_factory,
             reflection_service,
             ingress_dispatcher_loop.create_command_sender(),

src/ingress_grpc/src/pb.rs

@@ -0,0 +1,71 @@
+use once_cell::sync::Lazy;
+use prost_reflect::{DescriptorPool, MethodDescriptor};
+use restate_service_metadata::MethodDescriptorRegistry;
+use std::collections::HashMap;
+use std::convert::AsRef;
+
+pub(crate) mod grpc {
+    pub(crate) mod reflection {
+        #![allow(warnings)]
+        #![allow(clippy::all)]
+        #![allow(unknown_lints)]
+        include!(concat!(env!("OUT_DIR"), "/grpc.reflection.v1alpha.rs"));
+    }
+}
+pub(crate) mod restate {
+    pub(crate) mod services {
+        #![allow(warnings)]
+        #![allow(clippy::all)]
+        #![allow(unknown_lints)]
+        include!(concat!(env!("OUT_DIR"), "/dev.restate.rs"));
+    }
+}
+
+pub(crate) static DEV_RESTATE_DESCRIPTOR_POOL: Lazy<DescriptorPool> = Lazy::new(|| {
+    DescriptorPool::decode(
+        include_bytes!(concat!(env!("OUT_DIR"), "/file_descriptor_set.bin")).as_ref(),
+    )
+    .expect("The built-in descriptor pool should be valid")
+});
+
+// TODO this is a temporary solution until we have a schema registry where we can distinguish between ingress only services
+//  see https://github.com/restatedev/restate/issues/43#issuecomment-1597174972
+#[derive(Clone)]
+pub struct MethodDescriptorRegistryWithIngressService<MDR> {
+    method_descriptor_registry: MDR,
+}
+
+impl<MDR> MethodDescriptorRegistryWithIngressService<MDR> {
+    pub(crate) fn new(method_descriptor_registry: MDR) -> Self {
+        Self {
+            method_descriptor_registry,
+        }
+    }
+}
+
+impl<MDR: MethodDescriptorRegistry> MethodDescriptorRegistry
+    for MethodDescriptorRegistryWithIngressService<MDR>
+{
+    fn resolve_method_descriptor(
+        &self,
+        svc_name: &str,
+        method_name: &str,
+    ) -> Option<MethodDescriptor> {
+        if svc_name.starts_with("dev.restate") {
+            return DEV_RESTATE_DESCRIPTOR_POOL
+                .get_service_by_name(svc_name)
+                .and_then(|s| s.methods().find(|m| m.name() == method_name));
+        }
+        self.method_descriptor_registry
+            .resolve_method_descriptor(svc_name, method_name)
+    }
+
+    fn list_methods(&self, svc_name: &str) -> Option<HashMap<String, MethodDescriptor>> {
+        if svc_name.starts_with("dev.restate") {
+            return DEV_RESTATE_DESCRIPTOR_POOL
+                .get_service_by_name(svc_name)
+                .map(|s| s.methods().map(|m| (m.name().to_string(), m)).collect());
+        }
+        self.method_descriptor_registry.list_methods(svc_name)
+    }
+}