// ListenAndServe starts a DNS server that exposes services and values stored in etcd (if etcdclient
// is not nil). It will block until the server exits.
// TODO: hoist the service accessor out of this package so it can be reused.
func ListenAndServe(config *server.Config, client *client.Client, etcdclient *etcd.Client) error {
stop := make(chan struct{})
accessor := NewCachedServiceAccessor(client, stop)
resolver := NewServiceResolver(config, accessor, client, openshiftFallback)
resolvers := server.FirstBackend{resolver}
if etcdclient != nil {
resolvers = append(resolvers, backendetcd.NewBackend(etcdclient, &backendetcd.Config{
Ttl: config.Ttl,
Priority: config.Priority,
}))
}
s := server.New(resolvers, config)
defer close(stop)
return s.Run()
}
func newTestServer(t *testing.T, c bool) *server {
Port += 10
StrPort = strconv.Itoa(Port)
s := new(server)
client := etcd.NewClient([]string{"http://127.0.0.1:4001"})
// TODO(miek): why don't I use NewServer??
s.group = new(sync.WaitGroup)
s.scache = cache.New(100, 0)
s.rcache = cache.New(100, 0)
if c {
s.rcache = cache.New(100, 60) // 100 items, 60s ttl
}
s.config = new(Config)
s.config.Domain = "skydns.test."
s.config.DnsAddr = "127.0.0.1:" + StrPort
s.config.Nameservers = []string{"8.8.4.4:53"}
SetDefaults(s.config)
s.config.Local = "104.server1.development.region1.skydns.test."
s.config.Priority = 10
s.config.RCacheTtl = RCacheTtl
s.config.Ttl = 3600
s.config.Ndots = 2
prometheusPort = "12300"
prometheusSubsystem = "test"
prometheusNamespace = "test"
if !metricsDone {
metricsDone = true
Metrics()
}
s.dnsUDPclient = &dns.Client{Net: "udp", ReadTimeout: 2 * s.config.ReadTimeout, WriteTimeout: 2 * s.config.ReadTimeout, SingleInflight: true}
s.dnsTCPclient = &dns.Client{Net: "tcp", ReadTimeout: 2 * s.config.ReadTimeout, WriteTimeout: 2 * s.config.ReadTimeout, SingleInflight: true}
s.backend = backendetcd.NewBackend(client, &backendetcd.Config{
Ttl: s.config.Ttl,
Priority: s.config.Priority,
})
go s.Run()
// Yeah, yeah, should do a proper fix.
time.Sleep(500 * time.Millisecond)
return s
}
func newTestServer(t *testing.T, c bool) *server {
Port += 10
StrPort = strconv.Itoa(Port)
s := new(server)
client, _ := etcd.New(etcd.Config{
Endpoints: []string{"http://127.0.0.1:2379/"},
Transport: etcd.DefaultTransport,
})
kapi := etcd.NewKeysAPI(client)
// TODO(miek): why don't I use NewServer??
s.group = new(sync.WaitGroup)
s.scache = cache.New(100, 0)
s.rcache = cache.New(100, 0)
if c {
s.rcache = cache.New(100, 60) // 100 items, 60s ttl
}
s.config = new(Config)
s.config.Domain = "skydns.test."
s.config.DnsAddr = "127.0.0.1:" + StrPort
s.config.Nameservers = []string{"8.8.4.4:53"}
SetDefaults(s.config)
s.config.Local = "104.server1.development.region1.skydns.test."
s.config.Priority = 10
s.config.RCacheTtl = RCacheTtl
s.config.Ttl = 3600
s.config.Ndots = 2
s.dnsUDPclient = &dns.Client{Net: "udp", ReadTimeout: 2 * s.config.ReadTimeout, WriteTimeout: 2 * s.config.ReadTimeout, SingleInflight: true}
s.dnsTCPclient = &dns.Client{Net: "tcp", ReadTimeout: 2 * s.config.ReadTimeout, WriteTimeout: 2 * s.config.ReadTimeout, SingleInflight: true}
s.backend = backendetcd.NewBackend(kapi, ctx, &backendetcd.Config{
Ttl: s.config.Ttl,
Priority: s.config.Priority,
})
go s.Run()
time.Sleep(500 * time.Millisecond) // Yeah, yeah, should do a proper fix
return s
}
func main() {
flag.Parse()
machines := strings.Split(machine, ",")
client := newClient(machines, tlspem, tlskey, cacert)
if nameserver != "" {
for _, hostPort := range strings.Split(nameserver, ",") {
if err := validateHostPort(hostPort); err != nil {
log.Fatalf("skydns: nameserver is invalid: %s", err)
}
config.Nameservers = append(config.Nameservers, hostPort)
}
}
if err := validateHostPort(config.DnsAddr); err != nil {
log.Fatalf("skydns: addr is invalid: %s", err)
}
if err := loadConfig(client, config); err != nil {
log.Fatalf("skydns: %s", err)
}
if err := server.SetDefaults(config); err != nil {
log.Fatalf("skydns defaults could not be set from /etc/resolv.conf: %v", err)
}
if config.Local != "" {
config.Local = dns.Fqdn(config.Local)
}
backend := backendetcd.NewBackend(client, &backendetcd.Config{
Ttl: config.Ttl,
Priority: config.Priority,
})
s := server.New(backend, config)
if discover {
go func() {
recv := make(chan *etcd.Response)
go client.Watch("/_etcd/machines/", 0, true, recv, nil)
duration := 1 * time.Second
for {
select {
case n := <-recv:
if n != nil {
if client := updateClient(n, tlskey, tlspem, cacert); client != nil {
backend.UpdateClient(client)
}
duration = 1 * time.Second // reset
} else {
// we can see an n == nil, probably when we can't connect to etcd.
log.Printf("skydns: etcd machine cluster update failed, sleeping %s + ~3s", duration)
time.Sleep(duration + (time.Duration(rand.Float32() * 3e9))) // Add some random.
duration *= 2
if duration > 32*time.Second {
duration = 32 * time.Second
}
}
}
}
}()
}
if stub {
s.UpdateStubZones()
go func() {
recv := make(chan *etcd.Response)
go client.Watch(msg.Path(config.Domain)+"/dns/stub/", 0, true, recv, nil)
duration := 1 * time.Second
for {
select {
case n := <-recv:
if n != nil {
s.UpdateStubZones()
log.Printf("skydns: stubzone update")
duration = 1 * time.Second // reset
} else {
// we can see an n == nil, probably when we can't connect to etcd.
log.Printf("skydns: stubzone update failed, sleeping %s + ~3s", duration)
time.Sleep(duration + (time.Duration(rand.Float32() * 3e9))) // Add some random.
duration *= 2
if duration > 32*time.Second {
duration = 32 * time.Second
}
}
}
}
}()
}
stats.Collect() // Graphite
server.Metrics() // Prometheus
if err := s.Run(); err != nil {
log.Fatalf("skydns: %s", err)
}
}
func (lk LocalkubeServer) NewDNSServer(rootDomain, clusterIP, kubeAPIServer string) (*DNSServer, error) {
// setup backing etcd store
peerURLs := []string{"http://localhost:9256"}
DNSEtcdURLs := []string{"http://localhost:49090"}
publicIP, err := lk.GetHostIP()
if err != nil {
return nil, err
}
serverAddress := fmt.Sprintf("%s:%d", publicIP.String(), 53)
etcdServer, err := lk.NewEtcd(DNSEtcdURLs, peerURLs, DNSName, lk.GetDNSDataDirectory())
if err != nil {
return nil, err
}
// setup skydns
cfg := etcd.Config{
Endpoints: DNSEtcdURLs,
Transport: etcd.DefaultTransport,
}
etcdClient, err := etcd.New(cfg)
if err != nil {
return nil, err
}
keysApi := etcd.NewKeysAPI(etcdClient)
skyConfig := &skydns.Config{
DnsAddr: serverAddress,
Domain: rootDomain,
}
dnsAddress, err := net.ResolveUDPAddr("udp", serverAddress)
if err != nil {
return nil, err
}
skydns.SetDefaults(skyConfig)
backend := backendetcd.NewBackend(
keysApi,
context.Background(),
&backendetcd.Config{
Ttl: skyConfig.Ttl,
Priority: skyConfig.Priority,
})
skyServer := skydns.New(backend, skyConfig)
// setup so prometheus doesn't run into nil
metrics.Metrics()
// setup kube2sky
k2s := kube2sky.NewKube2Sky(rootDomain, DNSEtcdURLs[0], "", kubeAPIServer, 10*time.Second, 8081)
return &DNSServer{
etcd: etcdServer,
sky: skyServer,
kube2sky: k2s,
dnsServerAddr: dnsAddress,
clusterIP: clusterIP,
}, nil
}
func main() {
flag.Parse()
machines := strings.Split(machine, ",")
client, err := newEtcdClient(machines, tlspem, tlskey, cacert)
if err != nil {
panic(err)
}
if nameserver != "" {
for _, hostPort := range strings.Split(nameserver, ",") {
if err := validateHostPort(hostPort); err != nil {
log.Fatalf("skydns: nameserver is invalid: %s", err)
}
config.Nameservers = append(config.Nameservers, hostPort)
}
}
if err := validateHostPort(config.DnsAddr); err != nil {
log.Fatalf("skydns: addr is invalid: %s", err)
}
if err := loadConfig(client, config); err != nil {
log.Fatalf("skydns: %s", err)
}
if err := server.SetDefaults(config); err != nil {
log.Fatalf("skydns: defaults could not be set from /etc/resolv.conf: %v", err)
}
if config.Local != "" {
config.Local = dns.Fqdn(config.Local)
}
backend := backendetcd.NewBackend(client, ctx, &backendetcd.Config{
Ttl: config.Ttl,
Priority: config.Priority,
})
s := server.New(backend, config)
if stub {
s.UpdateStubZones()
go func() {
duration := 1 * time.Second
var watcher etcd.Watcher
watcher = client.Watcher(msg.Path(config.Domain)+"/dns/stub/", &etcd.WatcherOptions{AfterIndex: 0, Recursive: true})
for {
_, err := watcher.Next(ctx)
if err != nil {
//
log.Printf("skydns: stubzone update failed, sleeping %s + ~3s", duration)
time.Sleep(duration + (time.Duration(rand.Float32() * 3e9))) // Add some random.
duration *= 2
if duration > 32*time.Second {
duration = 32 * time.Second
}
} else {
s.UpdateStubZones()
log.Printf("skydns: stubzone update")
duration = 1 * time.Second // reset
}
}
}()
}
if err := metrics.Metrics(); err != nil {
log.Fatalf("skydns: %s", err)
} else {
log.Printf("skydns: metrics enabled on :%s%s", metrics.Port, metrics.Path)
}
if err := s.Run(); err != nil {
log.Fatalf("skydns: %s", err)
}
}
func main() {
flag.Parse()
if config.Version {
fmt.Printf("skydns server version: %s\n", server.Version)
os.Exit(0)
}
machines := strings.Split(machine, ",")
var clientptr *etcdv3.Client
var err error
var clientv3 etcdv3.Client
var clientv2 etcd.KeysAPI
if config.Etcd3 {
clientptr, err = newEtcdV3Client(machines, tlspem, tlskey, cacert)
clientv3 = *clientptr
} else {
clientv2, err = newEtcdV2Client(machines, tlspem, tlskey, cacert, username, password)
}
if err != nil {
panic(err)
}
if nameserver != "" {
for _, hostPort := range strings.Split(nameserver, ",") {
if err := validateHostPort(hostPort); err != nil {
log.Fatalf("skydns: nameserver is invalid: %s", err)
}
config.Nameservers = append(config.Nameservers, hostPort)
}
}
if err := validateHostPort(config.DnsAddr); err != nil {
log.Fatalf("skydns: addr is invalid: %s", err)
}
if config.Etcd3 {
if err := loadEtcdV3Config(clientv3, config); err != nil {
log.Fatalf("skydns: %s", err)
}
} else {
if err := loadEtcdV2Config(clientv2, config); err != nil {
log.Fatalf("skydns: %s", err)
}
}
if err := server.SetDefaults(config); err != nil {
log.Fatalf("skydns: defaults could not be set from /etc/resolv.conf: %v", err)
}
if config.Local != "" {
config.Local = dns.Fqdn(config.Local)
}
var backend server.Backend
if config.Etcd3 {
backend = backendetcdv3.NewBackendv3(clientv3, ctx, &backendetcdv3.Config{
Ttl: config.Ttl,
Priority: config.Priority,
})
} else {
backend = backendetcd.NewBackend(clientv2, ctx, &backendetcd.Config{
Ttl: config.Ttl,
Priority: config.Priority,
})
}
s := server.New(backend, config)
if stub {
s.UpdateStubZones()
go func() {
duration := 1 * time.Second
if config.Etcd3 {
var watcher etcdv3.WatchChan
watcher = clientv3.Watch(ctx, msg.Path(config.Domain)+"/dns/stub/", etcdv3.WithPrefix())
for wresp := range watcher {
if wresp.Err() != nil {
log.Printf("skydns: stubzone update failed, sleeping %s + ~3s", duration)
time.Sleep(duration + (time.Duration(rand.Float32() * 3e9)))
duration *= 2
if duration > 32*time.Second {
duration = 32 * time.Second
}
} else {
s.UpdateStubZones()
log.Printf("skydns: stubzone update")
duration = 1 * time.Second //reset
}
}
} else {
var watcher etcd.Watcher
watcher = clientv2.Watcher(msg.Path(config.Domain)+"/dns/stub/", &etcd.WatcherOptions{AfterIndex: 0, Recursive: true})
for {
_, err := watcher.Next(ctx)
if err != nil {
//
log.Printf("skydns: stubzone update failed, sleeping %s + ~3s", duration)
time.Sleep(duration + (time.Duration(rand.Float32() * 3e9))) // Add some random.
duration *= 2
if duration > 32*time.Second {
duration = 32 * time.Second
}
} else {
s.UpdateStubZones()
log.Printf("skydns: stubzone update")
duration = 1 * time.Second // reset
}
}
}
}()
}
if err := metrics.Metrics(); err != nil {
log.Fatalf("skydns: %s", err)
} else {
log.Printf("skydns: metrics enabled on :%s%s", metrics.Port, metrics.Path)
}
if err := s.Run(); err != nil {
log.Fatalf("skydns: %s", err)
}
}