examples: Simple logging interceptor and filter

examples/json/client/logger.go

@@ -0,0 +1,37 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/yarpc/yarpc-go/transport"
+
+	"golang.org/x/net/context"
+)
+
+type requestLogFilter struct{}
+
+func (requestLogFilter) Apply(
+	ctx context.Context, request *transport.Request, out transport.Outbound) (*transport.Response, error) {
+	fmt.Printf("sending a request to %q\n", request.Procedure)
+	return out.Call(ctx, request)
+}

examples/json/client/main.go

@@ -109,6 +109,7 @@ func main() {
 	rpc := yarpc.New(yarpc.Config{
 		Name:      "keyvalue-client",
 		Outbounds: transport.Outbounds{"keyvalue": outbound},
+		Filters:   yarpc.Filters{requestLogFilter{}},
 	})
 
 	client := json.New(rpc.Channel("keyvalue"))

examples/json/json.t

@@ -17,6 +17,16 @@ Test code:
   > set baz qux
   > get baz
   > INPUT
+  sending a request to "get"
+  received a request to "get"
   foo = 
+  sending a request to "set"
+  received a request to "set"
+  sending a request to "get"
+  received a request to "get"
   foo = bar
+  sending a request to "set"
+  received a request to "set"
+  sending a request to "get"
+  received a request to "get"
   baz = qux

examples/json/server/logger.go

@@ -0,0 +1,37 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/yarpc/yarpc-go/transport"
+
+	"golang.org/x/net/context"
+)
+
+type requestLogInterceptor struct{}
+
+func (requestLogInterceptor) Apply(
+	ctx context.Context, req *transport.Request, resw transport.ResponseWriter, handler transport.Handler) error {
+	fmt.Printf("received a request to %q\n", req.Procedure)
+	return handler.Handle(ctx, req, resw)
+}

examples/json/server/main.go

@@ -83,6 +83,7 @@ func main() {
 			tch.NewInbound(channel, tch.ListenAddr(":28941")),
 			http.NewInbound(":24034"),
 		},
+		Interceptors: yarpc.Interceptors{requestLogInterceptor{}},
 	})
 
 	handler := handler{items: make(map[string]string)}

rpc.go

@@ -51,14 +51,20 @@ type RPC interface {
 	Stop() error
 }
 
+// Filters is a collection of transport-level Filters.
+type Filters []transport.Filter
+
+// Interceptors is a collection of transport-level Interceptors.
+type Interceptors []transport.Interceptor
+
 // Config specifies the parameters of a new RPC constructed via New.
 type Config struct {
 	Name      string
 	Inbounds  []transport.Inbound
 	Outbounds transport.Outbounds
 
-	Filters      []transport.Filter
-	Interceptors []transport.Interceptor
+	Filters      Filters
+	Interceptors Interceptors
 
 	// TODO FallbackHandler for catch-all endpoints
 }
@@ -69,13 +75,15 @@ func New(cfg Config) RPC {
 		panic("a service name is required")
 	}
 
+	filters := []transport.Filter(cfg.Filters)
+	interceptors := []transport.Interceptor(cfg.Interceptors)
 	return rpc{
 		Name:        cfg.Name,
 		Registry:    transport.NewMapRegistry(cfg.Name),
 		Inbounds:    cfg.Inbounds,
 		Outbounds:   cfg.Outbounds,
-		Filter:      transport.ChainFilters(cfg.Filters...),
-		Interceptor: transport.ChainInterceptors(cfg.Interceptors...),
+		Filter:      transport.ChainFilters(filters...),
+		Interceptor: transport.ChainInterceptors(interceptors...),
 	}
 }