You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: srv.go
    path of file: ./repos/goldfish/vendor/github.com/coreos/etcd/pkg/srv
    
    the code of the file until where you have to start completion: // Copyright 2015 The etcd Authors
//
// 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
//
//     http://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 srv looks up DNS SRV records.
package srv

import (
	"fmt"
	"net"
	"net/url"
	"strings"

	"github.com/coreos/etcd/pkg/types"
)

var (
	// indirection for testing
	lookupSRV      = net.LookupSRV // net.DefaultResolver.LookupSRV when ctxs don't conflict
	resolveTCPAddr = net.ResolveTCPAddr
)

// GetCluster gets the cluster information via DNS discovery.
// Also sees each entry as a separate instance.
func GetCluster(service, name, dns string, apurls types.URLs) ([]string, error) {
	tempName := int(0)
	tcp2ap := make(map[string]url.URL)

	// First, resolve the apurls
	for _, url := range apurls {
		tcpAddr, err := resolveTCPAddr("tcp", url.Host)
		if err != nil {
			return nil, err
		}
		tcp2ap[tcpAddr.String()] = url
	}

	stringParts := []s
    
func GetCluster(service, name, dns string, apurls types.URLs) ([]string, error) {
	tempName := int(0)
	tcp2ap := make(map[string]url.URL)

	// First, resolve the apurls
	for _, url := range apurls {
		tcpAddr, err := resolveTCPAddr("tcp", url.Host)
		if err != nil {
			return nil, err
		}
		tcp2ap[tcpAddr.String()] = url
	}

	stringParts := []string{}
	updateNodeMap := func(service, scheme string) error {
		_, addrs, err := lookupSRV(service, "tcp", dns)
		if err != nil {
			return err
		}
		for _, srv := range addrs {
			port := fmt.Sprintf("%d", srv.Port)
			host := net.JoinHostPort(srv.Target, port)
			tcpAddr, terr := resolveTCPAddr("tcp", host)
			if terr != nil {
				err = terr
				continue
			}
			n := ""
			url, ok := tcp2ap[tcpAddr.String()]
			if ok {
				n = name
			}
			if n == "" {
				n = fmt.Sprintf("%d", tempName)
				tempName++
			}
			// SRV records have a trailing dot but URL shouldn't.
			shortHost := strings.TrimSuffix(srv.Target, ".")
			urlHost := net.JoinHostPort(shortHost, port)
			stringParts = append(stringParts, fmt.Sprintf("%s=%s://%s", n, scheme, urlHost))
			if ok && url.Scheme != scheme {
				err = fmt.Errorf("bootstrap at %s from DNS for %s has scheme mismatch with expected peer %s", scheme+"://"+urlHost, service, url.String())
			}
		}
		if len(stringParts) == 0 {
			return err
		}
		return nil
	}

	failCount := 0
	err := updateNodeMap(service+"-ssl", "https")
	srvErr := make([]string, 2)
	if err != nil {
		srvErr[0] = fmt.Sprintf("error querying DNS SRV records for _%s-ssl %s", service, err)
		failCount++
	}
	err = updateNodeMap(service, "http")
	if err != nil {
		srvErr[1] = fmt.Sprintf("error querying DNS SRV records for _%s %s", service, err)
		failCount++
	}
	if failCount == 2 {
		return nil, fmt.Errorf("srv: too many errors querying DNS SRV records (%q, %q)", srvErr[0], srvErr[1])
	}
	return stringParts, nil
}