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package main
import (
"fmt"
"io"
"log"
"os"
"path/filepath"
"sync"
"flag"
"github.com/mpolden/zdns"
"github.com/mpolden/zdns/cache"
"github.com/mpolden/zdns/dns"
"github.com/mpolden/zdns/dns/dnsutil"
"github.com/mpolden/zdns/http"
"github.com/mpolden/zdns/signal"
"github.com/mpolden/zdns/sql"
)
const (
name = "zdns"
logPrefix = name + ": "
configName = "." + name + "rc"
)
type server interface{ ListenAndServe() error }
type cli struct {
servers []server
wg sync.WaitGroup
}
func defaultConfigFile() string { return filepath.Join(os.Getenv("HOME"), configName) }
func readConfig(file string) (zdns.Config, error) {
f, err := os.Open(file)
if err != nil {
return zdns.Config{}, err
}
defer f.Close()
return zdns.ReadConfig(f)
}
func fatal(err error) {
if err == nil {
return
}
fmt.Fprintf(os.Stderr, "%s: %s\n", logPrefix, err)
os.Exit(1)
}
func (c *cli) runServer(server server) {
c.wg.Add(1)
go func() {
defer c.wg.Done()
if err := server.ListenAndServe(); err != nil {
fatal(err)
}
}()
}
func newCli(out io.Writer, args []string, configFile string, sig chan os.Signal) (*cli, error) {
cl := flag.CommandLine
cl.SetOutput(out)
confFile := cl.String("f", configFile, "config file `path`")
help := cl.Bool("h", false, "print usage")
cl.Parse(args)
if *help {
cl.Usage()
return nil, fmt.Errorf("usage option given")
}
// Config
config, err := readConfig(*confFile)
fatal(err)
// Logging and signal handling
log.SetOutput(out)
log.SetPrefix(logPrefix)
log.SetFlags(log.Lshortfile)
sigHandler := signal.NewHandler(sig)
// SQL backends
var (
sqlLogger *sql.Logger
sqlCache *sql.Cache
)
if config.DNS.Database != "" {
sqlClient, err := sql.New(config.DNS.Database)
fatal(err)
// Logger
sqlLogger = sql.NewLogger(sqlClient, config.DNS.LogMode, config.DNS.LogTTL)
sigHandler.OnClose(sqlLogger)
// Cache
sqlCache = sql.NewCache(sqlClient)
sigHandler.OnClose(sqlCache)
}
// DNS client
dnsClient := dnsutil.NewClient(config.Resolver.Protocol, config.Resolver.Timeout, config.DNS.Resolvers...)
// Cache
var dnsCache *cache.Cache
var cacheDNS *dnsutil.Client
if config.DNS.CachePrefetch {
cacheDNS = dnsClient
}
if sqlCache != nil && config.DNS.CachePersist {
dnsCache = cache.NewWithBackend(config.DNS.CacheSize, cacheDNS, sqlCache)
} else {
dnsCache = cache.New(config.DNS.CacheSize, cacheDNS)
}
sigHandler.OnClose(dnsCache)
// DNS server
proxy, err := dns.NewProxy(dnsCache, dnsClient, sqlLogger)
fatal(err)
sigHandler.OnClose(proxy)
dnsSrv, err := zdns.NewServer(proxy, config)
fatal(err)
sigHandler.OnReload(dnsSrv)
sigHandler.OnClose(dnsSrv)
servers := []server{dnsSrv}
// HTTP server
if config.DNS.ListenHTTP != "" {
httpSrv := http.NewServer(dnsCache, sqlLogger, sqlCache, config.DNS.ListenHTTP)
sigHandler.OnClose(httpSrv)
servers = append(servers, httpSrv)
}
return &cli{servers: servers}, nil
}
func (c *cli) run() {
for _, s := range c.servers {
c.runServer(s)
}
c.wg.Wait()
}
func main() {
c, err := newCli(os.Stderr, os.Args[1:], defaultConfigFile(), make(chan os.Signal, 1))
if err == nil {
c.run()
}
}
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