cmd/k8s-operator: support setting a custom hostname.

Updates #502

Signed-off-by: David Anderson <danderson@tailscale.com>
This commit is contained in:
David Anderson 2023-01-25 10:16:59 -08:00
parent 2adbb48632
commit 06f1192d3d
5 changed files with 183 additions and 11 deletions

View File

@ -13,6 +13,7 @@
// variables. All configuration is optional.
//
// - TS_AUTHKEY: the authkey to use for login.
// - TS_HOSTNAME: the hostname to request for the node.
// - TS_ROUTES: subnet routes to advertise.
// - TS_DEST_IP: proxy all incoming Tailscale traffic to the given
// destination.
@ -74,6 +75,7 @@ func main() {
cfg := &settings{
AuthKey: defaultEnvs([]string{"TS_AUTHKEY", "TS_AUTH_KEY"}, ""),
Hostname: defaultEnv("TS_HOSTNAME", ""),
Routes: defaultEnv("TS_ROUTES", ""),
ProxyTo: defaultEnv("TS_DEST_IP", ""),
DaemonExtraArgs: defaultEnv("TS_TAILSCALED_EXTRA_ARGS", ""),
@ -394,6 +396,9 @@ func tailscaleUp(ctx context.Context, cfg *settings) error {
if cfg.Routes != "" {
args = append(args, "--advertise-routes="+cfg.Routes)
}
if cfg.Hostname != "" {
args = append(args, "--hostname="+cfg.Hostname)
}
if cfg.ExtraArgs != "" {
args = append(args, strings.Fields(cfg.ExtraArgs)...)
}
@ -522,6 +527,7 @@ func installIPTablesRule(ctx context.Context, dstStr string, tsIPs []netip.Prefi
// settings is all the configuration for containerboot.
type settings struct {
AuthKey string
Hostname string
Routes string
ProxyTo string
DaemonExtraArgs string

View File

@ -550,6 +550,22 @@ type phase struct {
},
},
},
{
Name: "hostname",
Env: map[string]string{
"TS_HOSTNAME": "my-server",
},
Phases: []phase{
{
WantCmds: []string{
"/usr/bin/tailscaled --socket=/tmp/tailscaled.sock --state=mem: --statedir=/tmp --tun=userspace-networking",
"/usr/bin/tailscale --socket=/tmp/tailscaled.sock up --accept-dns=false --hostname=my-server",
},
}, {
Notify: runningNotify,
},
},
},
}
for _, test := range tests {

View File

@ -43,6 +43,7 @@
"tailscale.com/ipn/store/kubestore"
"tailscale.com/tsnet"
"tailscale.com/types/logger"
"tailscale.com/util/dnsname"
)
func main() {
@ -235,8 +236,9 @@ func main() {
FinalizerName = "tailscale.com/finalizer"
AnnotationExpose = "tailscale.com/expose"
AnnotationTags = "tailscale.com/tags"
AnnotationExpose = "tailscale.com/expose"
AnnotationTags = "tailscale.com/tags"
AnnotationHostname = "tailscale.com/hostname"
)
// ServiceReconciler is a simple ControllerManagedBy example implementation.
@ -370,6 +372,11 @@ func (a *ServiceReconciler) maybeCleanup(ctx context.Context, logger *zap.Sugare
// This function adds a finalizer to svc, ensuring that we can handle orderly
// deprovisioning later.
func (a *ServiceReconciler) maybeProvision(ctx context.Context, logger *zap.SugaredLogger, svc *corev1.Service) error {
hostname, err := nameForService(svc)
if err != nil {
return err
}
if !slices.Contains(svc.Finalizers, FinalizerName) {
// This log line is printed exactly once during initial provisioning,
// because once the finalizer is in place this block gets skipped. So,
@ -396,7 +403,7 @@ func (a *ServiceReconciler) maybeProvision(ctx context.Context, logger *zap.Suga
if err != nil {
return fmt.Errorf("failed to create or get API key secret: %w", err)
}
_, err = a.reconcileSTS(ctx, logger, svc, hsvc, secretName)
_, err = a.reconcileSTS(ctx, logger, svc, hsvc, secretName, hostname)
if err != nil {
return fmt.Errorf("failed to reconcile statefulset: %w", err)
}
@ -558,7 +565,7 @@ func (a *ServiceReconciler) newAuthKey(ctx context.Context, tags []string) (stri
//go:embed manifests/proxy.yaml
var proxyYaml []byte
func (a *ServiceReconciler) reconcileSTS(ctx context.Context, logger *zap.SugaredLogger, parentSvc, headlessSvc *corev1.Service, authKeySecret string) (*appsv1.StatefulSet, error) {
func (a *ServiceReconciler) reconcileSTS(ctx context.Context, logger *zap.SugaredLogger, parentSvc, headlessSvc *corev1.Service, authKeySecret, hostname string) (*appsv1.StatefulSet, error) {
var ss appsv1.StatefulSet
if err := yaml.Unmarshal(proxyYaml, &ss); err != nil {
return nil, fmt.Errorf("failed to unmarshal proxy spec: %w", err)
@ -573,6 +580,10 @@ func (a *ServiceReconciler) reconcileSTS(ctx context.Context, logger *zap.Sugare
corev1.EnvVar{
Name: "TS_KUBE_SECRET",
Value: authKeySecret,
},
corev1.EnvVar{
Name: "TS_HOSTNAME",
Value: hostname,
})
ss.ObjectMeta = metav1.ObjectMeta{
Name: headlessSvc.Name,
@ -679,3 +690,13 @@ func defaultEnv(envName, defVal string) string {
}
return v
}
func nameForService(svc *corev1.Service) (string, error) {
if h, ok := svc.Annotations[AnnotationHostname]; ok {
if err := dnsname.ValidLabel(h); err != nil {
return "", fmt.Errorf("invalid Tailscale hostname %q: %w", h, err)
}
return h, nil
}
return svc.Namespace + "-" + svc.Name, nil
}

View File

@ -66,7 +66,7 @@ func TestLoadBalancerClass(t *testing.T) {
expectEqual(t, fc, expectedSecret(fullName))
expectEqual(t, fc, expectedHeadlessService(shortName))
expectEqual(t, fc, expectedSTS(shortName, fullName))
expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
// Normally the Tailscale proxy pod would come up here and write its info
// into the secret. Simulate that, then verify reconcile again and verify
@ -187,7 +187,7 @@ func TestAnnotations(t *testing.T) {
expectEqual(t, fc, expectedSecret(fullName))
expectEqual(t, fc, expectedHeadlessService(shortName))
expectEqual(t, fc, expectedSTS(shortName, fullName))
expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
want := &corev1.Service{
TypeMeta: metav1.TypeMeta{
Kind: "Service",
@ -284,7 +284,7 @@ func TestAnnotationIntoLB(t *testing.T) {
expectEqual(t, fc, expectedSecret(fullName))
expectEqual(t, fc, expectedHeadlessService(shortName))
expectEqual(t, fc, expectedSTS(shortName, fullName))
expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
// Normally the Tailscale proxy pod would come up here and write its info
// into the secret. Simulate that, since it would have normally happened at
@ -328,7 +328,7 @@ func TestAnnotationIntoLB(t *testing.T) {
expectReconciled(t, sr, "default", "test")
// None of the proxy machinery should have changed...
expectEqual(t, fc, expectedHeadlessService(shortName))
expectEqual(t, fc, expectedSTS(shortName, fullName))
expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
// ... but the service should have a LoadBalancer status.
want = &corev1.Service{
@ -400,7 +400,7 @@ func TestLBIntoAnnotation(t *testing.T) {
expectEqual(t, fc, expectedSecret(fullName))
expectEqual(t, fc, expectedHeadlessService(shortName))
expectEqual(t, fc, expectedSTS(shortName, fullName))
expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
// Normally the Tailscale proxy pod would come up here and write its info
// into the secret. Simulate that, then verify reconcile again and verify
@ -457,7 +457,7 @@ func TestLBIntoAnnotation(t *testing.T) {
expectReconciled(t, sr, "default", "test")
expectEqual(t, fc, expectedHeadlessService(shortName))
expectEqual(t, fc, expectedSTS(shortName, fullName))
expectEqual(t, fc, expectedSTS(shortName, fullName, "default-test"))
want = &corev1.Service{
TypeMeta: metav1.TypeMeta{
@ -481,6 +481,108 @@ func TestLBIntoAnnotation(t *testing.T) {
expectEqual(t, fc, want)
}
func TestCustomHostname(t *testing.T) {
fc := fake.NewFakeClient()
ft := &fakeTSClient{}
zl, err := zap.NewDevelopment()
if err != nil {
t.Fatal(err)
}
sr := &ServiceReconciler{
Client: fc,
tsClient: ft,
defaultTags: []string{"tag:k8s"},
operatorNamespace: "operator-ns",
proxyImage: "tailscale/tailscale",
logger: zl.Sugar(),
}
// Create a service that we should manage, and check that the initial round
// of objects looks right.
mustCreate(t, fc, &corev1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: "test",
Namespace: "default",
// The apiserver is supposed to set the UID, but the fake client
// doesn't. So, set it explicitly because other code later depends
// on it being set.
UID: types.UID("1234-UID"),
Annotations: map[string]string{
"tailscale.com/expose": "true",
"tailscale.com/hostname": "reindeer-flotilla",
},
},
Spec: corev1.ServiceSpec{
ClusterIP: "10.20.30.40",
Type: corev1.ServiceTypeClusterIP,
},
})
expectReconciled(t, sr, "default", "test")
fullName, shortName := findGenName(t, fc, "default", "test")
expectEqual(t, fc, expectedSecret(fullName))
expectEqual(t, fc, expectedHeadlessService(shortName))
expectEqual(t, fc, expectedSTS(shortName, fullName, "reindeer-flotilla"))
want := &corev1.Service{
TypeMeta: metav1.TypeMeta{
Kind: "Service",
APIVersion: "v1",
},
ObjectMeta: metav1.ObjectMeta{
Name: "test",
Namespace: "default",
Finalizers: []string{"tailscale.com/finalizer"},
UID: types.UID("1234-UID"),
Annotations: map[string]string{
"tailscale.com/expose": "true",
"tailscale.com/hostname": "reindeer-flotilla",
},
},
Spec: corev1.ServiceSpec{
ClusterIP: "10.20.30.40",
Type: corev1.ServiceTypeClusterIP,
},
}
expectEqual(t, fc, want)
// Turn the service back into a ClusterIP service, which should make the
// operator clean up.
mustUpdate(t, fc, "default", "test", func(s *corev1.Service) {
delete(s.ObjectMeta.Annotations, "tailscale.com/expose")
})
// synchronous StatefulSet deletion triggers a requeue. But, the StatefulSet
// didn't create any child resources since this is all faked, so the
// deletion goes through immediately.
expectReconciled(t, sr, "default", "test")
expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
// Second time around, the rest of cleanup happens.
expectReconciled(t, sr, "default", "test")
expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
expectMissing[corev1.Service](t, fc, "operator-ns", shortName)
expectMissing[corev1.Secret](t, fc, "operator-ns", fullName)
want = &corev1.Service{
TypeMeta: metav1.TypeMeta{
Kind: "Service",
APIVersion: "v1",
},
ObjectMeta: metav1.ObjectMeta{
Name: "test",
Namespace: "default",
UID: types.UID("1234-UID"),
Annotations: map[string]string{
"tailscale.com/hostname": "reindeer-flotilla",
},
},
Spec: corev1.ServiceSpec{
ClusterIP: "10.20.30.40",
Type: corev1.ServiceTypeClusterIP,
},
}
expectEqual(t, fc, want)
}
func expectedSecret(name string) *corev1.Secret {
return &corev1.Secret{
TypeMeta: metav1.TypeMeta{
@ -529,7 +631,7 @@ func expectedHeadlessService(name string) *corev1.Service {
}
}
func expectedSTS(stsName, secretName string) *appsv1.StatefulSet {
func expectedSTS(stsName, secretName, hostname string) *appsv1.StatefulSet {
return &appsv1.StatefulSet{
TypeMeta: metav1.TypeMeta{
Kind: "StatefulSet",
@ -578,6 +680,7 @@ func expectedSTS(stsName, secretName string) *appsv1.StatefulSet {
{Name: "TS_AUTH_ONCE", Value: "true"},
{Name: "TS_DEST_IP", Value: "10.20.30.40"},
{Name: "TS_KUBE_SECRET", Value: secretName},
{Name: "TS_HOSTNAME", Value: hostname},
},
SecurityContext: &corev1.SecurityContext{
Capabilities: &corev1.Capabilities{

View File

@ -6,6 +6,7 @@
package dnsname
import (
"errors"
"fmt"
"strings"
)
@ -94,6 +95,31 @@ func (f FQDN) Contains(other FQDN) bool {
return strings.HasSuffix(other.WithTrailingDot(), cmp)
}
// ValidLabel reports whether label is a valid DNS label.
func ValidLabel(label string) error {
if len(label) == 0 {
return errors.New("empty DNS label")
}
if len(label) > maxLabelLength {
return fmt.Errorf("%q is too long, max length is %d bytes", label, maxLabelLength)
}
if !isalphanum(label[0]) {
return fmt.Errorf("%q is not a valid DNS label: must start with a letter or number", label)
}
if !isalphanum(label[len(label)-1]) {
return fmt.Errorf("%q is not a valid DNS label: must end with a letter or number", label)
}
if len(label) < 2 {
return nil
}
for i := 1; i < len(label)-1; i++ {
if !isdnschar(label[i]) {
return fmt.Errorf("%q is not a valid DNS label: contains invalid character %q", label, label[i])
}
}
return nil
}
// SanitizeLabel takes a string intended to be a DNS name label
// and turns it into a valid name label according to RFC 1035.
func SanitizeLabel(label string) string {