github.com/envoyproxy/go-control-plane/envoy v1.37.0: v3.GrpcService_EnvoyGrpc

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/envoyproxy/go-control-plane/envoy/config/core/v3.GrpcService_EnvoyGrpc in pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0
Demonstrate these symbols/APIs:
  - github.com/envoyproxy/go-control-plane/envoy/config/core/v3.GrpcService_EnvoyGrpc

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:20ffe442da6e2ef5afe83e5cff11d8bc20d3b1eb6261d34682c476b9d41c5174","contract":["GrpcService_EnvoyGrpc initializes with cluster name, authority, retry policy, and max receive message length, validates fields, and integrates into GrpcService"],"goal":"verify github.com/envoyproxy/go-control-plane/envoy/config/core/v3.GrpcService_EnvoyGrpc in pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0","kind":"HOW","packages":["pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0"],"schemaVersion":1,"symbols":["github.com/envoyproxy/go-control-plane/envoy/config/core/v3.GrpcService_EnvoyGrpc"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0","symbols":["github.com/envoyproxy/go-control-plane/envoy/config/core/v3.GrpcService_EnvoyGrpc"],"verifierAdapter":"golang@1"}

module sample

go 1.24.0

require (
	github.com/envoyproxy/go-control-plane/envoy v1.37.0
	google.golang.org/protobuf v1.36.11
)

require (
	github.com/cncf/xds/go v0.0.0-20251110193048-8bfbf64dc13e // indirect
	github.com/envoyproxy/protoc-gen-validate v1.3.0 // indirect
	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 // indirect
)

github.com/cncf/xds/go v0.0.0-20251110193048-8bfbf64dc13e h1:gt7U1Igw0xbJdyaCM5H2CnlAlPSkzrhsebQB6WQWjLA=
github.com/cncf/xds/go v0.0.0-20251110193048-8bfbf64dc13e/go.mod h1:KdCmV+x/BuvyMxRnYBlmVaq4OLiKW6iRQfvC62cvdkI=
github.com/envoyproxy/go-control-plane/envoy v1.37.0 h1:u3riX6BoYRfF4Dr7dwSOroNfdSbEPe9Yyl09/B6wBrQ=
github.com/envoyproxy/go-control-plane/envoy v1.37.0/go.mod h1:DReE9MMrmecPy+YvQOAOHNYMALuowAnbjjEMkkWOi6A=
github.com/envoyproxy/protoc-gen-validate v1.3.0 h1:TvGH1wof4H33rezVKWSpqKz5NXWg5VPuZ0uONDT6eb4=
github.com/envoyproxy/protoc-gen-validate v1.3.0/go.mod h1:HvYl7zwPa5mffgyeTUHA9zHIH36nmrm7oCbo4YKoSWA=
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/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 h1:GFCKgmp0tecUJ0sJuv4pzYCqS9+RGSn52M3FUwPs+uo=
github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10/go.mod h1:t/avpk3KcrXxUnYOhZhMXJlSEyie6gQbtLq5NM3loB8=
google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=

{
  "schemaVersion": 1,
  "goal": "verify github.com/envoyproxy/go-control-plane/envoy/config/core/v3.GrpcService_EnvoyGrpc in pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/envoyproxy/go-control-plane/envoy@v1.37.0"
  ],
  "symbols": [
    "github.com/envoyproxy/go-control-plane/envoy/config/core/v3.GrpcService_EnvoyGrpc"
  ]
}

package main

import (
	"fmt"
	"time"

	corev3 "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
	"google.golang.org/protobuf/types/known/durationpb"
	"google.golang.org/protobuf/types/known/wrapperspb"
)

func main() {
	retryPolicy := &corev3.RetryPolicy{
		RetryBackOff: &corev3.BackoffStrategy{
			BaseInterval: durationpb.New(200 * time.Millisecond),
			MaxInterval:  durationpb.New(2 * time.Second),
		},
		NumRetries: wrapperspb.UInt32(3),
	}

	envoyGrpc := &corev3.GrpcService_EnvoyGrpc{
		ClusterName:             "backend_grpc_cluster",
		Authority:               "backend.example.com",
		RetryPolicy:             retryPolicy,
		MaxReceiveMessageLength: wrapperspb.UInt32(4 * 1024 * 1024),
		SkipEnvoyHeaders:        true,
	}

	if err := envoyGrpc.Validate(); err != nil {
		panic(fmt.Sprintf("validation failed: %v", err))
	}

	if envoyGrpc.GetClusterName() != "backend_grpc_cluster" {
		panic("unexpected cluster name")
	}

	if envoyGrpc.GetAuthority() != "backend.example.com" {
		panic("unexpected authority")
	}

	if !envoyGrpc.GetSkipEnvoyHeaders() {
		panic("unexpected skip envoy headers value")
	}

	if envoyGrpc.GetMaxReceiveMessageLength().GetValue() != 4*1024*1024 {
		panic("unexpected max receive message length")
	}

	if envoyGrpc.GetRetryPolicy().GetNumRetries().GetValue() != 3 {
		panic("unexpected retry policy num retries")
	}

	grpcService := &corev3.GrpcService{
		TargetSpecifier: &corev3.GrpcService_EnvoyGrpc_{
			EnvoyGrpc: envoyGrpc,
		},
		Timeout: durationpb.New(5 * time.Second),
	}

	if err := grpcService.Validate(); err != nil {
		panic(fmt.Sprintf("grpcService validation failed: %v", err))
	}

	extracted := grpcService.GetEnvoyGrpc()
	if extracted == nil {
		panic("expected non-nil EnvoyGrpc from GrpcService")
	}

	if extracted.GetClusterName() != "backend_grpc_cluster" {
		panic("unexpected cluster name from extracted EnvoyGrpc")
	}

	// Verify empty ClusterName validation failure if proto rules require cluster_name min_len: 1
	invalidEnvoyGrpc := &corev3.GrpcService_EnvoyGrpc{
		ClusterName: "",
	}
	if err := invalidEnvoyGrpc.Validate(); err == nil {
		panic("expected validation error for empty cluster_name")
	}

	fmt.Println("PASS: GrpcService_EnvoyGrpc verification successful")
}