Add a buildable mock server entrypoint

cmd/metric-server/go.mod

@@ -0,0 +1,25 @@
+module github.com/GoogleCloudPlatform/opentelemetry-operations-go/cmd/metric-server
+
+go 1.24.0
+
+replace (
+	github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/cloudmock => ../../internal/cloudmock
+	github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/resourcemapping => ../../../internal/resourcemapping
+)
+
+require github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/cloudmock v0.0.0-00010101000000-000000000000
+
+require (
+	cloud.google.com/go/logging v1.13.0 // indirect
+	cloud.google.com/go/longrunning v0.6.7 // indirect
+	cloud.google.com/go/monitoring v1.24.2 // indirect
+	cloud.google.com/go/trace v1.11.6 // indirect
+	golang.org/x/net v0.44.0 // indirect
+	golang.org/x/sys v0.36.0 // indirect
+	golang.org/x/text v0.29.0 // indirect
+	google.golang.org/genproto v0.0.0-20250922171735-9219d122eba9 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20250922171735-9219d122eba9 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250922171735-9219d122eba9 // indirect
+	google.golang.org/grpc v1.75.1 // indirect
+	google.golang.org/protobuf v1.36.9 // indirect
+)

cmd/metric-server/go.sum

@@ -0,0 +1,48 @@
+cloud.google.com/go/logging v1.13.0 h1:7j0HgAp0B94o1YRDqiqm26w4q1rDMH7XNRU34lJXHYc=
+cloud.google.com/go/logging v1.13.0/go.mod h1:36CoKh6KA/M0PbhPKMq6/qety2DCAErbhXT62TuXALA=
+cloud.google.com/go/longrunning v0.6.7 h1:IGtfDWHhQCgCjwQjV9iiLnUta9LBCo8R9QmAFsS/PrE=
+cloud.google.com/go/longrunning v0.6.7/go.mod h1:EAFV3IZAKmM56TyiE6VAP3VoTzhZzySwI/YI1s/nRsY=
+cloud.google.com/go/monitoring v1.24.2 h1:5OTsoJ1dXYIiMiuL+sYscLc9BumrL3CarVLL7dd7lHM=
+cloud.google.com/go/monitoring v1.24.2/go.mod h1:x7yzPWcgDRnPEv3sI+jJGBkwl5qINf+6qY4eq0I9B4U=
+cloud.google.com/go/trace v1.11.6 h1:2O2zjPzqPYAHrn3OKl029qlqG6W8ZdYaOWRyr8NgMT4=
+cloud.google.com/go/trace v1.11.6/go.mod h1:GA855OeDEBiBMzcckLPE2kDunIpC72N+Pq8WFieFjnI=
+github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
+github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
+github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
+go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
+go.opentelemetry.io/otel v1.37.0 h1:9zhNfelUvx0KBfu/gb+ZgeAfAgtWrfHJZcAqFC228wQ=
+go.opentelemetry.io/otel v1.37.0/go.mod h1:ehE/umFRLnuLa/vSccNq9oS1ErUlkkK71gMcN34UG8I=
+go.opentelemetry.io/otel/metric v1.37.0 h1:mvwbQS5m0tbmqML4NqK+e3aDiO02vsf/WgbsdpcPoZE=
+go.opentelemetry.io/otel/metric v1.37.0/go.mod h1:04wGrZurHYKOc+RKeye86GwKiTb9FKm1WHtO+4EVr2E=
+go.opentelemetry.io/otel/sdk v1.37.0 h1:ItB0QUqnjesGRvNcmAcU0LyvkVyGJ2xftD29bWdDvKI=
+go.opentelemetry.io/otel/sdk v1.37.0/go.mod h1:VredYzxUvuo2q3WRcDnKDjbdvmO0sCzOvVAiY+yUkAg=
+go.opentelemetry.io/otel/sdk/metric v1.37.0 h1:90lI228XrB9jCMuSdA0673aubgRobVZFhbjxHHspCPc=
+go.opentelemetry.io/otel/sdk/metric v1.37.0/go.mod h1:cNen4ZWfiD37l5NhS+Keb5RXVWZWpRE+9WyVCpbo5ps=
+go.opentelemetry.io/otel/trace v1.37.0 h1:HLdcFNbRQBE2imdSEgm/kwqmQj1Or1l/7bW6mxVK7z4=
+go.opentelemetry.io/otel/trace v1.37.0/go.mod h1:TlgrlQ+PtQO5XFerSPUYG0JSgGyryXewPGyayAWSBS0=
+golang.org/x/net v0.44.0 h1:evd8IRDyfNBMBTTY5XRF1vaZlD+EmWx6x8PkhR04H/I=
+golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
+golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=
+gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
+gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
+google.golang.org/genproto v0.0.0-20250922171735-9219d122eba9 h1:LvZVVaPE0JSqL+ZWb6ErZfnEOKIqqFWUJE2D0fObSmc=
+google.golang.org/genproto v0.0.0-20250922171735-9219d122eba9/go.mod h1:QFOrLhdAe2PsTp3vQY4quuLKTi9j3XG3r6JPPaw7MSc=
+google.golang.org/genproto/googleapis/api v0.0.0-20250922171735-9219d122eba9 h1:jm6v6kMRpTYKxBRrDkYAitNJegUeO1Mf3Kt80obv0gg=
+google.golang.org/genproto/googleapis/api v0.0.0-20250922171735-9219d122eba9/go.mod h1:LmwNphe5Afor5V3R5BppOULHOnt2mCIf+NxMd4XiygE=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250922171735-9219d122eba9 h1:V1jCN2HBa8sySkR5vLcCSqJSTMv093Rw9EJefhQGP7M=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250922171735-9219d122eba9/go.mod h1:HSkG/KdJWusxU1F6CNrwNDjBMgisKxGnc5dAZfT0mjQ=
+google.golang.org/grpc v1.75.1 h1:/ODCNEuf9VghjgO3rqLcfg8fiOP0nSluljWFlDxELLI=
+google.golang.org/grpc v1.75.1/go.mod h1:JtPAzKiq4v1xcAB2hydNlWI2RnF85XXcV0mhKXr2ecQ=
+google.golang.org/protobuf v1.36.9 h1:w2gp2mA27hUeUzj9Ex9FBjsBm40zfaDtEWow293U7Iw=
+google.golang.org/protobuf v1.36.9/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=

cmd/metric-server/main.go

@@ -0,0 +1,49 @@
+// Copyright 2025 Google LLC
+//
+// 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
+//
+//      https://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 main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/cloudmock"
+)
+
+var endpoint = flag.String("endpoint", "localhost:8080", "endpoint to host server")
+
+func main() {
+	srv, err := cloudmock.NewMetricTestServerWithEndpoint(*endpoint)
+	if err != nil {
+		log.Fatal(err)
+	}
+	go srv.Serve()
+
+	ticker := time.NewTicker(3 * time.Second)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		reqs := srv.CreateTimeSeriesRequests()
+		for _, req := range reqs {
+			reqBytes, err := json.Marshal(req)
+			if err != nil {
+				log.Fatal(err)
+			}
+			fmt.Println(string(reqBytes))
+		}
+	}
+}

internal/cloudmock/metrics.go

@@ -184,3 +184,23 @@ func NewMetricTestServer() (*MetricsTestServer, error) {
 
 	return testServer, nil
 }
+
+func NewMetricTestServerWithEndpoint(endpoint string) (*MetricsTestServer, error) {
+	srv := grpc.NewServer()
+	lis, err := net.Listen("tcp", endpoint)
+	if err != nil {
+		return nil, err
+	}
+	testServer := &MetricsTestServer{
+		Endpoint: lis.Addr().String(),
+		lis:      lis,
+		srv:      srv,
+	}
+
+	monitoringpb.RegisterMetricServiceServer(
+		srv,
+		&fakeMetricServiceServer{metricsTestServer: testServer},
+	)
+
+	return testServer, nil
+}