refactor: convert the Hyper server setup to use Tower

Cargo.toml

@@ -14,31 +14,33 @@ exclude = [
 ]
 
 [dependencies]
-clap = { version = "4.2.1", features = ["env", "std", "cargo"] }
-serde = "1.0.137"
-serde_json = "1.0.81"
+anyhow = "1.0.71"
+base64 = "0.21.1"
+clap = { version = "4.3.0", features = ["env", "std", "cargo"] }
+futures = "0.3.28"
+http = "0.2.9"
+hyper = { version = "0.14.26", features = ["full"] }
+itertools = "0.10.5"
+maplit = "1.0.2"
 pact_matching = "~1.1.0"
 pact_verifier = "~1.0.0"
 pact_models = "~1.1.2"
-maplit = "1.0.2"
-itertools = "0.10.5"
-hyper = { version = "0.14.25", features = ["full"] }
-http = "0.2.9"
-tokio = { version = "1.27.0", features = ["full"] }
-futures = "0.3.28"
-base64 = "0.21.0"
-regex = "1.7.3"
-reqwest = { version = "0.11.16", default-features = false, features = ["json", "rustls-tls-native-roots"] }
-tower-service = "0.3.2"
-anyhow = "1.0.70"
+regex = "1.8.2"
+reqwest = { version = "0.11.18", default-features = false, features = ["json", "rustls-tls-native-roots"] }
+serde = "1.0.163"
+serde_json = "1.0.96"
+tokio = { version = "1.28.1", features = ["full"] }
+tower = { version = "0.4.13", features = [ "full" ] }
+tower-service = { version = "0.3.2" }
+tower-http = { version = "0.4.0", features = [ "full" ] }
 tracing = { version = "0.1.37", features = [ "log" ] }
-tracing-core = "0.1.30"
-tracing-subscriber = "0.3.16"
+tracing-core = "0.1.31"
+tracing-subscriber = "0.3.17"
 
 [dev-dependencies]
 expectest = "0.12.0"
 rand = "0.8.5"
 pretty_assertions = "1.3.0"
 test-log = "0.2.11"
 env_logger = "0.10.0"
-trycmd = "0.14.13"
+trycmd = "0.14.16"

src/server.rs

@@ -1,3 +1,4 @@
+use std::future::{Ready, ready};
 use std::pin::Pin;
 use std::process::ExitCode;
 
@@ -8,15 +9,18 @@ use futures::stream::StreamExt;
 use futures::task::{Context, Poll};
 use http::{Error, StatusCode};
 use hyper::{Body, Request as HyperRequest, Response as HyperResponse, Server};
+use hyper::server::conn::AddrStream;
 use itertools::Itertools;
-use maplit::*;
+use maplit::hashmap;
 use pact_matching::{CoreMatchingContext, DiffConfig, Mismatch};
 use pact_models::generators::GeneratorTestMode;
 use pact_models::prelude::*;
 use pact_models::prelude::v4::*;
 use pact_models::v4::http_parts::{HttpRequest, HttpResponse};
 use pact_models::v4::V4InteractionType;
 use regex::Regex;
+use tower::ServiceBuilder;
+use tower_http::trace::TraceLayer;
 use tower_service::Service;
 use tracing::{debug, error, info, warn};
 
@@ -32,6 +36,38 @@ pub struct ServerHandler {
   empty_provider_states: bool
 }
 
+#[derive(Clone)]
+struct ServerHandlerFactory {
+  inner: ServerHandler
+}
+
+impl ServerHandlerFactory {
+  pub fn new(handler: ServerHandler) -> Self {
+    ServerHandlerFactory {
+      inner: handler
+    }
+  }
+}
+
+impl Service<&AddrStream> for ServerHandlerFactory {
+  type Response = ServerHandler;
+  type Error = anyhow::Error;
+  type Future = Ready<Result<Self::Response, Self::Error>>;
+
+  fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    Poll::Ready(Ok(()))
+  }
+
+  fn call(&mut self, req: &AddrStream) -> Self::Future {
+    debug!("Accepting a new connection from {}", req.remote_addr());
+    let service = ServiceBuilder::new()
+      .layer(TraceLayer::new_for_http())
+      .service(self.inner.clone())
+      .into_inner();
+    ready(Ok(service))
+  }
+}
+
 impl ServerHandler {
   pub fn new(
     sources: Vec<(V4Pact, PactSource)>,
@@ -55,13 +91,7 @@ impl ServerHandler {
     let addr = ([0, 0, 0, 0], port).into();
     match Server::try_bind(&addr) {
       Ok(builder) => {
-        let server = builder
-          .serve(hyper::service::make_service_fn(|_| {
-            let inner = self.clone();
-            async {
-              Ok::<_, hyper::Error>(inner)
-            }
-          }));
+        let server = builder.serve(ServerHandlerFactory::new(self));
         info!("Server started on port {}", server.local_addr().port());
         block_on(server).map_err(|err| {
           error!("error occurred scheduling server future on Tokio runtime: {}", err);