if err != nil {
		t.Fatalf("loadcert: %v", err)
	}

	config := tls.Config{Certificates: []tls.Certificate{cert}}

	ln, err := tls.Listen("tcp", "127.0.0.1:0", &config)
	if err != nil {
		ln, err = tls.Listen("tcp", "[::1]:0", &config)
		if err != nil {
			t.Fatalf("server: listen: %v", err)
		}
	}

	go func() {
		conn, err := ln.Accept()
		if err != nil {
			t.Errorf("server: accept: %v", err)

	registry.MustRegister(metrics.RuntimeOperations)
	registry.MustRegister(metrics.RuntimeOperationsDuration)
	registry.MustRegister(metrics.RuntimeOperationsErrors)

	registry.Reset()

	l, err := net.Listen("tcp", "127.0.0.1:0")
	assert.NoError(t, err)
	defer l.Close()

	prometheusURL := "http://" + l.Addr().String() + "/metrics"
	mux := http.NewServeMux()

		}
	}
	if e.Err == nil {
		return fmt.Errorf("OpError.Err is empty: %v", e)
	}
	return nil
}

// parseDialError parses nestedErr and reports whether it is a valid
// error value from Dial, Listen functions.
// It returns nil when nestedErr is valid.
func parseDialError(nestedErr error) error {
	if nestedErr == nil {
		return nil
	}

	switch err := nestedErr.(type) {
	case *OpError:

 * {@link #armWatchProbe(File)} is called.
 *
 * When the probe is armed, a probe file is created (or re-created) under the hierarchy.
 * This should cause a file system event to be produced by the operating system.
 * We listen to those events specifically in {@link FileWatcherRegistry}.
 * Once the event arrives, {@link #triggerWatchProbe(String)} is called with the path,
 * and the probe becomes triggered (or proven).
 *

	if len(network) == 0 {
		network = "tcp"
	}

	ln, err := config.Listen(context.TODO(), network, addr)
	if err != nil {
		return nil, 0, fmt.Errorf("failed to listen on %v: %v", addr, err)
	}

	// get port
	tcpAddr, ok := ln.Addr().(*net.TCPAddr)
	if !ok {
		ln.Close()
		return nil, 0, fmt.Errorf("invalid listen address: %q", ln.Addr().String())
	}

	return ln, tcpAddr.Port, nil
}

package net_test

import (
	"context"
	"fmt"
	"io"
	"log"
	"net"
	"time"
)

func ExampleListener() {
	// Listen on TCP port 2000 on all available unicast and
	// anycast IP addresses of the local system.
	l, err := net.Listen("tcp", ":2000")
	if err != nil {
		log.Fatal(err)
	}
	defer l.Close()
	for {
		// Wait for a connection.
		conn, err := l.Accept()
		if err != nil {

	// which Dial("tcp", addr1, addr2) run on the machine at addr1 can
	// connect to a simultaneous Dial("tcp", addr2, addr1) run on the machine
	// at addr2, without either machine executing Listen. If laddr == nil,
	// it means we want the kernel to pick an appropriate originating local
	// address. Some Linux kernels cycle blindly through a fixed range of
	// local ports, regardless of destination port. If a kernel happens to

		"The identity provider for credential. Currently default supported identity provider is GoogleComputeEngine").Get()
	proxyXDSDebugViaAgent = env.Register("PROXY_XDS_DEBUG_VIA_AGENT", true,
		"If set to true, the agent will listen on tap port and offer pilot's XDS istio.io/debug debug API there.").Get()
	proxyXDSDebugViaAgentPort = env.Register("PROXY_XDS_DEBUG_VIA_AGENT_PORT", 15004,
		"Agent debugging port.").Get()

		Service:           ExternalSvc,
		Namespace:         e.Namespace,
		DefaultHostHeader: ExternalHostname,
		Ports:             ports.All(),
		// Set up TLS certs on the server. This will make the server listen with these credentials.
		TLSSettings: &common.TLSSettings{
			// Echo has these test certs baked into the docker image
			RootCert:   file.MustAsString(path.Join(env.IstioSrc, "tests/testdata/certs/dns/root-cert.pem")),

# The base path of dex and the external name of the OpenID Connect service.
# This is the canonical URL that all clients MUST use to refer to dex. If a
# path is provided, dex's HTTP service will listen at a non-root URL.
issuer: http://127.0.0.1:5556/dex

# The storage configuration determines where dex stores its state. Supported
# options include SQL flavors and Kubernetes third party resources.
#