Add gRPC Filter

CHANGELOG.md

@@ -8,6 +8,10 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Added
+
+- Add gRPC trace `Filter` to the `go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc` package to provide the way to filter the traces automatically generated in interceptors. (#2572)
+
 ### Changed
 
 - Upgraded all `semconv` package use to `v1.12.0`. (#2589)

instrumentation/google.golang.org/grpc/otelgrpc/filters.go

@@ -0,0 +1,204 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelgrpc // import "go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
+
+import (
+	"path"
+	"strings"
+)
+
+// Filter is a predicate used to determine whether a given request in
+// interceptor info should be traced. A Filter must return true if
+// the request should be traced.
+type Filter func(*interceptorInfo) bool
+
+type gRPCPath struct {
+	service string
+	method  string
+}
+
+// splitFullMethod splits path defined in gRPC protocol
+// and returns as gRPCPath object that has divided service and method names
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md
+// If name is not FullMethod, returned gRPCPath has empty service field.
+func splitFullMethod(name string) gRPCPath {
+	s, m := path.Split(name)
+	if s != "" {
+		s = path.Clean(s)
+		s = strings.TrimLeft(s, "/")
+	}
+	return gRPCPath{
+		service: s,
+		method:  m,
+	}
+}
+
+// Any takes a list of Filters and returns a Filter that
+// returns true if any Filter in the list returns true.
+func Any(fs ...Filter) Filter {
+	return func(i *interceptorInfo) bool {
+		for _, f := range fs {
+			if f(i) {
+				return true
+			}
+		}
+		return false
+	}
+}
+
+// All takes a list of Filters and returns a Filter that
+// returns true only if all Filters in the list return true.
+func All(fs ...Filter) Filter {
+	return func(i *interceptorInfo) bool {
+		for _, f := range fs {
+			if !f(i) {
+				return false
+			}
+		}
+		return true
+	}
+}
+
+// None takes a list of Filters and returns a Filter that returns
+// true only if none of the Filters in the list return true.
+func None(fs ...Filter) Filter {
+	return func(i *interceptorInfo) bool {
+		for _, f := range fs {
+			if f(i) {
+				return false
+			}
+		}
+		return true
+	}
+}
+
+// Not provides a convenience mechanism for inverting a Filter.
+func Not(f Filter) Filter {
+	return func(i *interceptorInfo) bool {
+		return !f(i)
+	}
+}
+
+// MethodName returns a Filter that returns true if the request's
+// method name matches the provided string n.
+func MethodName(n string) Filter {
+	return func(i *interceptorInfo) bool {
+		var p gRPCPath
+		switch i.typ {
+		case unaryServer:
+			p = splitFullMethod(i.usinfo.FullMethod)
+		case streamServer:
+			p = splitFullMethod(i.ssinfo.FullMethod)
+		case unaryClient, streamClient:
+			p = splitFullMethod(i.method)
+		default:
+			p = gRPCPath{
+				method: i.method,
+			}
+		}
+		return p.method == n
+	}
+}
+
+// MethodPrefix returns a Filter that returns true if the request's
+// method starts with the provided string pre.
+func MethodPrefix(pre string) Filter {
+	return func(i *interceptorInfo) bool {
+		var p gRPCPath
+		switch i.typ {
+		case unaryServer:
+			p = splitFullMethod(i.usinfo.FullMethod)
+		case streamServer:
+			p = splitFullMethod(i.ssinfo.FullMethod)
+		case unaryClient, streamClient:
+			p = splitFullMethod(i.method)
+		default:
+			p = gRPCPath{
+				method: i.method,
+			}
+		}
+		return strings.HasPrefix(p.method, pre)
+	}
+}
+
+// FullMethodName returns a Filter that returns true if the request's
+// full RPC method string, i.e. /package.service/method, starts with
+// the provided string n.
+func FullMethodName(n string) Filter {
+	return func(i *interceptorInfo) bool {
+		var fm string
+		switch i.typ {
+		case unaryClient, streamClient:
+			fm = i.method
+		case unaryServer:
+			fm = i.usinfo.FullMethod
+		case streamServer:
+			fm = i.ssinfo.FullMethod
+		default:
+			fm = i.method
+		}
+		return fm == n
+	}
+}
+
+// ServiceName returns a Filter that returns true if the request's
+// service name, i.e. package.service, matches s.
+func ServiceName(s string) Filter {
+	return func(i *interceptorInfo) bool {
+		var p gRPCPath
+		switch i.typ {
+		case unaryServer:
+			p = splitFullMethod(i.usinfo.FullMethod)
+		case streamServer:
+			p = splitFullMethod(i.ssinfo.FullMethod)
+		case unaryClient, streamClient:
+			p = splitFullMethod(i.method)
+		default:
+			p = gRPCPath{
+				method: i.method,
+			}
+		}
+		return p.service == s
+	}
+}
+
+// ServicePrefix returns a Filter that returns true if the request's
+// service name, i.e. package.service, starts with the provided string pre.
+func ServicePrefix(pre string) Filter {
+	return func(i *interceptorInfo) bool {
+		var p gRPCPath
+		switch i.typ {
+		case unaryServer:
+			p = splitFullMethod(i.usinfo.FullMethod)
+		case streamServer:
+			p = splitFullMethod(i.ssinfo.FullMethod)
+		case unaryClient, streamClient:
+			p = splitFullMethod(i.method)
+		default:
+			p = gRPCPath{
+				method: i.method,
+			}
+		}
+		return strings.HasPrefix(p.service, pre)
+	}
+}
+
+// NotHealthCheck returns a Filter that returns true if the request's
+// is not health check defined by gRPC Health Checking Protocol.
+// https://github.com/grpc/grpc/blob/master/doc/health-checking.md
+// This is the short of Not(MethodName("grpc.health.v1.Health/Check")).
+func NotHealthCheck() Filter {
+	return Not(ServicePrefix("grpc.health.v1.Health"))
+}