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

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.ConfigSource 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.ConfigSource

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:b8af1a0cbc3f5a1b0114deacaad97f53e9879458eec968f3835be351ddd23543","contract":["ConfigSource with ConfigSource_Path configures filesystem-based configuration source and validates","ConfigSource with ConfigSource_Ads configures Aggregated Discovery Service source and validates","ConfigSource with ConfigSource_ApiConfigSource configures dynamic gRPC API configuration source and validates"],"goal":"verify github.com/envoyproxy/go-control-plane/envoy/config/core/v3.ConfigSource 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.ConfigSource"]},"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.ConfigSource"],"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=

package main

import (
	"fmt"
	"time"

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

func main() {
	configSource := &corev3.ConfigSource{
		ConfigSourceSpecifier: &corev3.ConfigSource_Ads{
			Ads: &corev3.AggregatedConfigSource{},
		},
		ResourceApiVersion:  corev3.ApiVersion_V3,
		InitialFetchTimeout: durationpb.New(15 * time.Second),
	}

	if err := configSource.ValidateAll(); err != nil {
		panic(err)
	}

	fmt.Printf("ConfigSource configured with ADS, API version: %v\n", configSource.GetResourceApiVersion())
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/envoyproxy/go-control-plane/envoy/config/core/v3.ConfigSource 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.ConfigSource"
  ]
}

package main

import (
	"fmt"
	"os"
	"time"

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

func main() {
	// Assertion 1: ConfigSource with ConfigSource_Path configures filesystem-based configuration source and validates
	{
		csPath := &corev3.ConfigSource{
			ConfigSourceSpecifier: &corev3.ConfigSource_Path{
				Path: "/etc/envoy/cds.yaml",
			},
			ResourceApiVersion:  corev3.ApiVersion_V3,
			InitialFetchTimeout: durationpb.New(15 * time.Second),
		}

		if err := csPath.ValidateAll(); err != nil {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: ValidateAll error: %v\n", err)
			os.Exit(1)
		}

		if csPath.GetPath() != "/etc/envoy/cds.yaml" {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: expected path /etc/envoy/cds.yaml, got %s\n", csPath.GetPath())
			os.Exit(1)
		}

		pathSpecifier, ok := csPath.GetConfigSourceSpecifier().(*corev3.ConfigSource_Path)
		if !ok || pathSpecifier.Path != "/etc/envoy/cds.yaml" {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: ConfigSourceSpecifier mismatch\n")
			os.Exit(1)
		}

		if csPath.GetResourceApiVersion() != corev3.ApiVersion_V3 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: expected ResourceApiVersion V3, got %v\n", csPath.GetResourceApiVersion())
			os.Exit(1)
		}

		if csPath.GetInitialFetchTimeout().GetSeconds() != 15 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: expected initial fetch timeout 15s, got %d\n", csPath.GetInitialFetchTimeout().GetSeconds())
			os.Exit(1)
		}
	}

	// Assertion 2: ConfigSource with ConfigSource_Ads configures Aggregated Discovery Service source and validates
	{
		csAds := &corev3.ConfigSource{
			ConfigSourceSpecifier: &corev3.ConfigSource_Ads{
				Ads: &corev3.AggregatedConfigSource{},
			},
			ResourceApiVersion: corev3.ApiVersion_V3,
		}

		if err := csAds.ValidateAll(); err != nil {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: ValidateAll error: %v\n", err)
			os.Exit(1)
		}

		if csAds.GetAds() == nil {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: expected non-nil ADS config\n")
			os.Exit(1)
		}

		adsSpecifier, ok := csAds.GetConfigSourceSpecifier().(*corev3.ConfigSource_Ads)
		if !ok || adsSpecifier.Ads == nil {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: ConfigSourceSpecifier Ads mismatch\n")
			os.Exit(1)
		}
	}

	// Assertion 3: ConfigSource with ConfigSource_ApiConfigSource configures dynamic gRPC API configuration source and validates
	{
		csApi := &corev3.ConfigSource{
			ConfigSourceSpecifier: &corev3.ConfigSource_ApiConfigSource{
				ApiConfigSource: &corev3.ApiConfigSource{
					ApiType:             corev3.ApiConfigSource_GRPC,
					TransportApiVersion: corev3.ApiVersion_V3,
					GrpcServices: []*corev3.GrpcService{
						{
							TargetSpecifier: &corev3.GrpcService_EnvoyGrpc_{
								EnvoyGrpc: &corev3.GrpcService_EnvoyGrpc{
									ClusterName: "xds_cluster",
								},
							},
						},
					},
					SetNodeOnFirstMessageOnly: true,
				},
			},
			ResourceApiVersion: corev3.ApiVersion_V3,
		}

		if err := csApi.ValidateAll(); err != nil {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: ValidateAll error: %v\n", err)
			os.Exit(1)
		}

		apiConfig := csApi.GetApiConfigSource()
		if apiConfig == nil {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected non-nil ApiConfigSource\n")
			os.Exit(1)
		}

		if apiConfig.GetApiType() != corev3.ApiConfigSource_GRPC {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected ApiType GRPC, got %v\n", apiConfig.GetApiType())
			os.Exit(1)
		}

		if apiConfig.GetTransportApiVersion() != corev3.ApiVersion_V3 {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected TransportApiVersion V3, got %v\n", apiConfig.GetTransportApiVersion())
			os.Exit(1)
		}

		if len(apiConfig.GetGrpcServices()) != 1 {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected 1 GrpcService\n")
			os.Exit(1)
		}

		envoyGrpc := apiConfig.GetGrpcServices()[0].GetEnvoyGrpc()
		if envoyGrpc == nil || envoyGrpc.GetClusterName() != "xds_cluster" {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected GrpcService cluster xds_cluster\n")
			os.Exit(1)
		}

		if !apiConfig.GetSetNodeOnFirstMessageOnly() {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected SetNodeOnFirstMessageOnly to be true\n")
			os.Exit(1)
		}
	}

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