svc: Update stack diagnostic checks (#642)

This change updates and extends the diagnostic stack checks that we use
during development. No functional changes.

Author: olix0r

linkerd/app/core/src/svc.rs

@@ -55,10 +55,7 @@ impl<L> Layers<L> {
         Layers(Pair::new(self.0, outer))
     }
 
-    pub fn push_map_target<M: Clone>(
-        self,
-        map_target: M,
-    ) -> Layers<Pair<L, stack::MapTargetLayer<M>>> {
+    pub fn push_map_target<M>(self, map_target: M) -> Layers<Pair<L, stack::MapTargetLayer<M>>> {
         self.push(stack::MapTargetLayer::new(map_target))
     }
 
@@ -280,25 +277,43 @@ impl<S> Stack<S> {
     }
 
     /// Validates that this stack serves T-typed targets.
-    pub fn check_new_service<T>(self) -> Self
+    pub fn check_new<T>(self) -> Self
     where
         S: NewService<T>,
     {
         self
     }
 
-    /// Validates that this stack can be cloned
-    pub fn check_clone(self) -> Self
+    pub fn check_new_clone<T>(self) -> Self
     where
-        S: Clone,
+        S: NewService<T>,
+        S::Service: Clone,
     {
         self
     }
 
-    pub fn check_new_clone_service<T>(self) -> Self
+    /// Validates that this stack serves T-typed targets.
+    pub fn check_new_service<T, Req>(self) -> Self
     where
         S: NewService<T>,
-        S::Service: Clone,
+        S::Service: Service<Req>,
+    {
+        self
+    }
+
+    /// Validates that this stack serves T-typed targets.
+    pub fn check_clone_new_service<T, Req>(self) -> Self
+    where
+        S: NewService<T> + Clone,
+        S::Service: Service<Req>,
+    {
+        self
+    }
+
+    /// Validates that this stack can be cloned
+    pub fn check_clone(self) -> Self
+    where
+        S: Clone,
     {
         self
     }
@@ -327,15 +342,6 @@ impl<S> Stack<S> {
         self
     }
 
-    /// Validates that this stack serves T-typed targets.
-    pub fn check_new_service_routes<T, Req>(self) -> Self
-    where
-        S: NewService<T>,
-        S::Service: Service<Req>,
-    {
-        self
-    }
-
     /// Validates that this stack serves T-typed targets.
     pub fn check_make_service<T, U>(self) -> Self
     where

linkerd/app/inbound/src/lib.rs

@@ -206,7 +206,7 @@ impl Config {
             // Sets the per-route response classifier as a request
             // extension.
             .push(classify::Layer::new())
-            .check_new_clone_service::<dst::Route>();
+            .check_new_clone::<dst::Route>();
 
         // An HTTP client is created for each target via the endpoint stack.
         let http_target_cache = http_endpoint
@@ -245,7 +245,7 @@ impl Config {
             ))
             .into_new_service()
             // Caches profile stacks.
-            .check_new_service_routes::<Profile, Target>()
+            .check_new_service::<Profile, Target>()
             .cache(
                 svc::layers().push_on_response(
                     svc::layers()
@@ -261,7 +261,7 @@ impl Config {
             .instrument(|p: &Profile| info_span!("profile", addr = %p.addr()))
             .check_make_service::<Profile, Target>()
             .push(router::Layer::new(|()| ProfileTarget))
-            .check_new_service_routes::<(), Target>()
+            .check_new_service::<(), Target>()
             .new_service(());
 
         svc::stack(http_profile_cache)
@@ -359,7 +359,7 @@ impl Config {
             .push(router::Layer::new(RequestTarget::from))
             // Used by tap.
             .push_http_insert_target()
-            .check_new_service::<tls::accept::Meta>()
+            .check_new_service::<tls::accept::Meta, http::Request<_>>()
             .push_on_response(
                 svc::layers()
                     .push(http_admit_request)
@@ -368,7 +368,7 @@ impl Config {
                     .box_http_request()
                     .box_http_response(),
             )
-            .check_new_service::<tls::accept::Meta>()
+            .check_new_service::<tls::accept::Meta, http::Request<_>>()
             .instrument(|src: &tls::accept::Meta| {
                 info_span!(
                     "source",

linkerd/app/outbound/src/lib.rs

@@ -334,21 +334,17 @@ impl Config {
             .check_service::<Concrete<HttpEndpoint>>();
 
         let http_profile_route_proxy = svc::proxies()
-            .check_new_clone_service::<dst::Route>()
             .push(metrics.http_route_actual.into_layer::<classify::Response>())
             // Sets an optional retry policy.
             .push(retry::layer(metrics.http_route_retry))
-            .check_new_clone_service::<dst::Route>()
             // Sets an optional request timeout.
             .push(http::MakeTimeoutLayer::default())
-            .check_new_clone_service::<dst::Route>()
             // Records per-route metrics.
             .push(metrics.http_route.into_layer::<classify::Response>())
-            .check_new_clone_service::<dst::Route>()
             // Sets the per-route response classifier as a request
             // extension.
             .push(classify::Layer::new())
-            .check_new_clone_service::<dst::Route>();
+            .check_new_clone::<dst::Route>();
 
         // Routes `Logical` targets to a cached `Profile` stack, i.e. so that profile
         // resolutions are shared even as the type of request may vary.
@@ -388,7 +384,7 @@ impl Config {
             .instrument(|_: &Profile| info_span!("profile"))
             .check_make_service::<Profile, Logical<HttpEndpoint>>()
             .push(router::Layer::new(|()| ProfilePerTarget))
-            .check_new_service_routes::<(), Logical<HttpEndpoint>>()
+            .check_new_service::<(), Logical<HttpEndpoint>>()
             .new_service(());
 
         // Routes requests to their logical target.
@@ -487,7 +483,7 @@ impl Config {
             .push_make_ready()
             .push_timeout(dispatch_timeout)
             .push(router::Layer::new(LogicalPerRequest::from))
-            .check_new_service::<listen::Addrs>()
+            .check_new_service::<listen::Addrs, http::Request<_>>()
             // Used by tap.
             .push_http_insert_target()
             .push_on_response(
@@ -500,7 +496,7 @@ impl Config {
             .instrument(
                 |addrs: &listen::Addrs| info_span!("source", target.addr = %addrs.target_addr()),
             )
-            .check_new_service::<listen::Addrs>()
+            .check_new_service::<listen::Addrs, http::Request<_>>()
             .into_inner()
             .into_make_service();