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

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/endpoint/v3.ClusterLoadAssignment 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/endpoint/v3.ClusterLoadAssignment

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:sha256:2bbd2a16a101d08d15f8ab89cd540f586b121bf50a408359856354224523ff9b","contract":["ClusterLoadAssignment initializes with specified cluster name and endpoints","ClusterLoadAssignment provides access to configured locality lb endpoints and policy"],"goal":"verify github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3.ClusterLoadAssignment 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/endpoint/v3.ClusterLoadAssignment"]},"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/endpoint/v3.ClusterLoadAssignment"],"verifierAdapter":"golang@1"}

module sample

go 1.25.0

require github.com/envoyproxy/go-control-plane/envoy v1.37.0

require (
	cel.dev/expr v0.25.1 // indirect
	github.com/cncf/xds/go v0.0.0-20260202195803-dba9d589def2 // indirect
	github.com/envoyproxy/go-control-plane v0.14.0 // indirect
	github.com/envoyproxy/protoc-gen-validate v1.3.3 // indirect
	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 // indirect
	golang.org/x/net v0.49.0 // indirect
	golang.org/x/sys v0.40.0 // indirect
	golang.org/x/text v0.33.0 // indirect
	google.golang.org/genproto/googleapis/api v0.0.0-20251029180050-ab9386a59fda // indirect
	google.golang.org/genproto/googleapis/rpc v0.0.0-20251029180050-ab9386a59fda // indirect
	google.golang.org/grpc v1.78.0 // indirect
	google.golang.org/protobuf v1.36.11 // indirect
)

cel.dev/expr v0.25.1 h1:1KrZg61W6TWSxuNZ37Xy49ps13NUovb66QLprthtwi4=
cel.dev/expr v0.25.1/go.mod h1:hrXvqGP6G6gyx8UAHSHJ5RGk//1Oj5nXQ2NI02Nrsg4=
github.com/cncf/xds/go v0.0.0-20260202195803-dba9d589def2 h1:aBangftG7EVZoUb69Os8IaYg++6uMOdKK83QtkkvJik=
github.com/cncf/xds/go v0.0.0-20260202195803-dba9d589def2/go.mod h1:qwXFYgsP6T7XnJtbKlf1HP8AjxZZyzxMmc+Lq5GjlU4=
github.com/envoyproxy/go-control-plane v0.14.0 h1:hbG2kr4RuFj222B6+7T83thSPqLjwBIfQawTkC++2HA=
github.com/envoyproxy/go-control-plane v0.14.0/go.mod h1:NcS5X47pLl/hfqxU70yPwL9ZMkUlwlKxtAohpi2wBEU=
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/go-control-plane/envoy v1.39.0 h1:1uwRDYPYG8BIBU9Mj1sUAebNmlM6beu/ZKKweSLDxk8=
github.com/envoyproxy/go-control-plane/envoy v1.39.0/go.mod h1:5e4ylfTZO723MEEFsCpSW4ZEBWR8mwkEyXfwJBTCZ9c=
github.com/envoyproxy/protoc-gen-validate v1.3.3 h1:MVQghNeW+LZcmXe7SY1V36Z+WFMDjpqGAGacLe2T0ds=
github.com/envoyproxy/protoc-gen-validate v1.3.3/go.mod h1:TsndJ/ngyIdQRhMcVVGDDHINPLWB7C82oDArY51KfB0=
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=
golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
google.golang.org/genproto/googleapis/api v0.0.0-20251029180050-ab9386a59fda h1:+2XxjfsAu6vqFxwGBRcHiMaDCuZiqXGDUDVWVtrFAnE=
google.golang.org/genproto/googleapis/api v0.0.0-20251029180050-ab9386a59fda/go.mod h1:fDMmzKV90WSg1NbozdqrE64fkuTv6mlq2zxo9ad+3yo=
google.golang.org/genproto/googleapis/rpc v0.0.0-20251029180050-ab9386a59fda h1:i/Q+bfisr7gq6feoJnS/DlpdwEL4ihp41fvRiM3Ork0=
google.golang.org/genproto/googleapis/rpc v0.0.0-20251029180050-ab9386a59fda/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
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/endpoint/v3.ClusterLoadAssignment 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/endpoint/v3.ClusterLoadAssignment"
  ]
}

package main

import (
	"fmt"
	"os"

	corev3 "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
	endpointv3 "github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3"
)

func main() {
	cla := &endpointv3.ClusterLoadAssignment{
		ClusterName: "service_cluster",
		Endpoints: []*endpointv3.LocalityLbEndpoints{
			{
				Locality: &corev3.Locality{
					Region: "us-west-1",
					Zone:   "us-west-1a",
				},
				LbEndpoints: []*endpointv3.LbEndpoint{
					{
						HostIdentifier: &endpointv3.LbEndpoint_Endpoint{
							Endpoint: &endpointv3.Endpoint{
								Address: &corev3.Address{
									Address: &corev3.Address_SocketAddress{
										SocketAddress: &corev3.SocketAddress{
											Protocol: corev3.SocketAddress_TCP,
											Address:  "127.0.0.1",
											PortSpecifier: &corev3.SocketAddress_PortValue{
												PortValue: 8080,
											},
										},
									},
								},
							},
						},
					},
				},
			},
		},
		Policy: &endpointv3.ClusterLoadAssignment_Policy{},
	}

	// Assertion 1: ClusterLoadAssignment initializes with specified cluster name and endpoints
	if cla.GetClusterName() != "service_cluster" {
		fmt.Fprintf(os.Stderr, "expected cluster name 'service_cluster', got %q\n", cla.GetClusterName())
		os.Exit(1)
	}
	if len(cla.GetEndpoints()) != 1 {
		fmt.Fprintf(os.Stderr, "expected 1 LocalityLbEndpoints, got %d\n", len(cla.GetEndpoints()))
		os.Exit(1)
	}

	// Assertion 2: ClusterLoadAssignment provides access to configured locality lb endpoints and policy
	locality := cla.GetEndpoints()[0].GetLocality()
	if locality == nil || locality.GetRegion() != "us-west-1" || locality.GetZone() != "us-west-1a" {
		fmt.Fprintf(os.Stderr, "expected locality us-west-1/us-west-1a, got %v\n", locality)
		os.Exit(1)
	}

	if cla.GetPolicy() == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil policy\n")
		os.Exit(1)
	}

	fmt.Println("PASS: ClusterLoadAssignment contract passed")
}