cmd/k8s-operator: add support for Ingress resources

Previously, the operator would only monitor Services and create
a Tailscale StatefulSet which acted as a L3 proxy which proxied
traffic inbound to the Tailscale IP onto the services ClusterIP.

This extends that functionality to also monitor Ingress resources
where the `ingressClassName=tailscale` and similarly creates a
Tailscale StatefulSet, acting as a L7 proxy instead.

Users can override the desired hostname by setting:

```
- tls
  hosts:
  - "foo"
```

Hostnames specified under `rules` are ignored as we only create a single
host. This is emitted as an event for users to see.

Fixes #7895

Signed-off-by: Maisem Ali <maisem@tailscale.com>
pull/8826/head
Maisem Ali 9 months ago committed by Maisem Ali
parent 320f77bd24
commit c8dea67cbf

@ -0,0 +1,233 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build !plan9
package main
import (
"context"
"fmt"
"strings"
"go.uber.org/zap"
"golang.org/x/exp/slices"
corev1 "k8s.io/api/core/v1"
networkingv1 "k8s.io/api/networking/v1"
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/types"
"k8s.io/client-go/tools/record"
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/reconcile"
"tailscale.com/ipn"
"tailscale.com/types/opt"
)
type IngressReconciler struct {
client.Client
recorder record.EventRecorder
ssr *tailscaleSTSReconciler
logger *zap.SugaredLogger
}
func (a *IngressReconciler) Reconcile(ctx context.Context, req reconcile.Request) (_ reconcile.Result, err error) {
logger := a.logger.With("ingress-ns", req.Namespace, "ingress-name", req.Name)
logger.Debugf("starting reconcile")
defer logger.Debugf("reconcile finished")
ing := new(networkingv1.Ingress)
err = a.Get(ctx, req.NamespacedName, ing)
if apierrors.IsNotFound(err) {
// Request object not found, could have been deleted after reconcile request.
logger.Debugf("ingress not found, assuming it was deleted")
return reconcile.Result{}, nil
} else if err != nil {
return reconcile.Result{}, fmt.Errorf("failed to get ing: %w", err)
}
if !ing.DeletionTimestamp.IsZero() || !a.shouldExpose(ing) {
logger.Debugf("ingress is being deleted or should not be exposed, cleaning up")
return reconcile.Result{}, a.maybeCleanup(ctx, logger, ing)
}
return reconcile.Result{}, a.maybeProvision(ctx, logger, ing)
}
func (a *IngressReconciler) maybeCleanup(ctx context.Context, logger *zap.SugaredLogger, ing *networkingv1.Ingress) error {
ix := slices.Index(ing.Finalizers, FinalizerName)
if ix < 0 {
logger.Debugf("no finalizer, nothing to do")
return nil
}
if done, err := a.ssr.Cleanup(ctx, logger, childResourceLabels(ing.Name, ing.Namespace, "ingress")); err != nil {
return fmt.Errorf("failed to cleanup: %w", err)
} else if !done {
logger.Debugf("cleanup not done yet, waiting for next reconcile")
return nil
}
ing.Finalizers = append(ing.Finalizers[:ix], ing.Finalizers[ix+1:]...)
if err := a.Update(ctx, ing); err != nil {
return fmt.Errorf("failed to remove finalizer: %w", err)
}
// Unlike most log entries in the reconcile loop, this will get printed
// exactly once at the very end of cleanup, because the final step of
// cleanup removes the tailscale finalizer, which will make all future
// reconciles exit early.
logger.Infof("unexposed ingress from tailnet")
return nil
}
// maybeProvision ensures that ing is exposed over tailscale, taking any actions
// necessary to reach that state.
//
// This function adds a finalizer to ing, ensuring that we can handle orderly
// deprovisioning later.
func (a *IngressReconciler) maybeProvision(ctx context.Context, logger *zap.SugaredLogger, ing *networkingv1.Ingress) error {
if !slices.Contains(ing.Finalizers, FinalizerName) {
// This log line is printed exactly once during initial provisioning,
// because once the finalizer is in place this block gets skipped. So,
// this is a nice place to tell the operator that the high level,
// multi-reconcile operation is underway.
logger.Infof("exposing ingress over tailscale")
ing.Finalizers = append(ing.Finalizers, FinalizerName)
if err := a.Update(ctx, ing); err != nil {
return fmt.Errorf("failed to add finalizer: %w", err)
}
}
// magic443 is a fake hostname that we can use to tell containerboot to swap
// out with the real hostname once it's known.
const magic443 = "${TS_CERT_DOMAIN}:443"
sc := &ipn.ServeConfig{
TCP: map[uint16]*ipn.TCPPortHandler{
443: {
HTTPS: true,
},
},
Web: map[ipn.HostPort]*ipn.WebServerConfig{
magic443: {
Handlers: map[string]*ipn.HTTPHandler{},
},
},
}
if opt.Bool(ing.Annotations[AnnotationFunnel]).EqualBool(true) {
sc.AllowFunnel = map[ipn.HostPort]bool{
magic443: true,
}
}
web := sc.Web[magic443]
addIngressBackend := func(b *networkingv1.IngressBackend, path string) {
if b == nil {
return
}
if b.Service == nil {
a.recorder.Eventf(ing, corev1.EventTypeWarning, "InvalidIngressBackend", "backend for path %q is missing service", path)
return
}
var svc corev1.Service
if err := a.Get(ctx, types.NamespacedName{Namespace: ing.Namespace, Name: b.Service.Name}, &svc); err != nil {
a.recorder.Eventf(ing, corev1.EventTypeWarning, "InvalidIngressBackend", "failed to get service %q for path %q: %v", b.Service.Name, path, err)
return
}
if svc.Spec.ClusterIP == "" || svc.Spec.ClusterIP == "None" {
a.recorder.Eventf(ing, corev1.EventTypeWarning, "InvalidIngressBackend", "backend for path %q has invalid ClusterIP", path)
return
}
var port int32
if b.Service.Port.Name != "" {
for _, p := range svc.Spec.Ports {
if p.Name == b.Service.Port.Name {
port = p.Port
break
}
}
} else {
port = b.Service.Port.Number
}
if port == 0 {
a.recorder.Eventf(ing, corev1.EventTypeWarning, "InvalidIngressBackend", "backend for path %q has invalid port", path)
return
}
proto := "http://"
if port == 443 || b.Service.Port.Name == "https" {
proto = "https+insecure://"
}
web.Handlers[path] = &ipn.HTTPHandler{
Proxy: proto + svc.Spec.ClusterIP + ":" + fmt.Sprint(port) + path,
}
}
addIngressBackend(ing.Spec.DefaultBackend, "/")
for _, rule := range ing.Spec.Rules {
if rule.Host != "" {
a.recorder.Eventf(ing, corev1.EventTypeWarning, "InvalidIngressBackend", "rule with host %q ignored, unsupported", rule.Host)
continue
}
for _, p := range rule.HTTP.Paths {
addIngressBackend(&p.Backend, p.Path)
}
}
crl := childResourceLabels(ing.Name, ing.Namespace, "ingress")
var tags []string
if tstr, ok := ing.Annotations[AnnotationTags]; ok {
tags = strings.Split(tstr, ",")
}
hostname := ing.Namespace + "-" + ing.Name + "-ingress"
if ing.Spec.TLS != nil && len(ing.Spec.TLS) > 0 && len(ing.Spec.TLS[0].Hosts) > 0 {
hostname, _, _ = strings.Cut(ing.Spec.TLS[0].Hosts[0], ".")
}
sts := &tailscaleSTSConfig{
Hostname: hostname,
ParentResourceName: ing.Name,
ParentResourceUID: string(ing.UID),
ServeConfig: sc,
Tags: tags,
ChildResourceLabels: crl,
}
if err := a.ssr.Provision(ctx, logger, sts); err != nil {
return fmt.Errorf("failed to provision: %w", err)
}
_, tsHost, err := a.ssr.DeviceInfo(ctx, crl)
if err != nil {
return fmt.Errorf("failed to get device ID: %w", err)
}
if tsHost == "" {
logger.Debugf("no Tailscale hostname known yet, waiting for proxy pod to finish auth")
// No hostname yet. Wait for the proxy pod to auth.
ing.Status.LoadBalancer.Ingress = nil
if err := a.Status().Update(ctx, ing); err != nil {
return fmt.Errorf("failed to update ingress status: %w", err)
}
return nil
}
logger.Debugf("setting ingress hostname to %q", tsHost)
ing.Status.LoadBalancer.Ingress = []networkingv1.IngressLoadBalancerIngress{
{
Hostname: tsHost,
Ports: []networkingv1.IngressPortStatus{
{
Protocol: "TCP",
Port: 443,
},
},
},
}
if err := a.Status().Update(ctx, ing); err != nil {
return fmt.Errorf("failed to update ingress status: %w", err)
}
return nil
}
func (a *IngressReconciler) shouldExpose(ing *networkingv1.Ingress) bool {
return ing != nil &&
ing.Spec.IngressClassName != nil &&
*ing.Spec.IngressClassName == "tailscale"
}

@ -50,6 +50,9 @@ rules:
- apiGroups: [""]
resources: ["services", "services/status"]
verbs: ["*"]
- apiGroups: ["networking.k8s.io"]
resources: ["ingresses", "ingresses/status"]
verbs: ["*"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding

@ -2,7 +2,7 @@
# at build time and then uses to construct Tailscale proxy pods.
apiVersion: apps/v1
kind: StatefulSet
metadata:
metadata: {}
spec:
replicas: 1
template:

@ -0,0 +1,24 @@
# This file is not a complete manifest, it's a skeleton that the operator embeds
# at build time and then uses to construct Tailscale proxy pods.
apiVersion: apps/v1
kind: StatefulSet
metadata: {}
spec:
replicas: 1
template:
metadata:
deletionGracePeriodSeconds: 10
spec:
serviceAccountName: proxies
resources:
requests:
cpu: 1m
memory: 1Mi
containers:
- name: tailscale
imagePullPolicy: Always
env:
- name: TS_USERSPACE
value: "true"
- name: TS_AUTH_ONCE
value: "true"

@ -19,6 +19,7 @@ import (
"golang.org/x/oauth2/clientcredentials"
appsv1 "k8s.io/api/apps/v1"
corev1 "k8s.io/api/core/v1"
networkingv1 "k8s.io/api/networking/v1"
"k8s.io/apimachinery/pkg/types"
"k8s.io/client-go/rest"
"sigs.k8s.io/controller-runtime/pkg/builder"
@ -209,9 +210,6 @@ func startReconcilers(zlog *zap.SugaredLogger, tsNamespace string, restConfig *r
if ls[LabelManaged] != "true" {
return nil
}
if ls[LabelParentType] != "svc" {
return nil
}
return []reconcile.Request{
{
NamespacedName: types.NamespacedName{
@ -221,26 +219,42 @@ func startReconcilers(zlog *zap.SugaredLogger, tsNamespace string, restConfig *r
},
}
})
eventRecorder := mgr.GetEventRecorderFor("tailscale-operator")
ssr := &tailscaleSTSReconciler{
Client: mgr.GetClient(),
tsClient: tsClient,
defaultTags: strings.Split(tags, ","),
operatorNamespace: tsNamespace,
proxyImage: image,
proxyPriorityClassName: priorityClassName,
}
err = builder.
ControllerManagedBy(mgr).
For(&corev1.Service{}).
Watches(&appsv1.StatefulSet{}, reconcileFilter).
Watches(&corev1.Secret{}, reconcileFilter).
Complete(&ServiceReconciler{
ssr: &tailscaleSTSReconciler{
Client: mgr.GetClient(),
tsClient: tsClient,
defaultTags: strings.Split(tags, ","),
operatorNamespace: tsNamespace,
proxyImage: image,
proxyPriorityClassName: priorityClassName,
},
ssr: ssr,
Client: mgr.GetClient(),
logger: zlog.Named("service-reconciler"),
})
if err != nil {
startlog.Fatalf("could not create controller: %v", err)
}
err = builder.
ControllerManagedBy(mgr).
For(&networkingv1.Ingress{}).
Watches(&appsv1.StatefulSet{}, reconcileFilter).
Watches(&corev1.Secret{}, reconcileFilter).
Complete(&IngressReconciler{
ssr: ssr,
recorder: eventRecorder,
Client: mgr.GetClient(),
logger: zlog.Named("ingress-reconciler"),
})
if err != nil {
startlog.Fatalf("could not create controller: %v", err)
}
startlog.Infof("Startup complete, operator running, version: %s", version.Long())
if err := mgr.Start(signals.SetupSignalHandler()); err != nil {

@ -750,9 +750,9 @@ func expectedSTS(stsName, secretName, hostname, priorityClassName string) *appsv
Env: []corev1.EnvVar{
{Name: "TS_USERSPACE", Value: "false"},
{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},
{Name: "TS_DEST_IP", Value: "10.20.30.40"},
},
SecurityContext: &corev1.SecurityContext{
Capabilities: &corev1.Capabilities{

@ -8,6 +8,7 @@ package main
import (
"context"
_ "embed"
"encoding/json"
"fmt"
"os"
"strings"
@ -21,9 +22,11 @@ import (
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/yaml"
"tailscale.com/client/tailscale"
"tailscale.com/ipn"
"tailscale.com/tailcfg"
"tailscale.com/types/opt"
"tailscale.com/util/dnsname"
"tailscale.com/util/mak"
)
const (
@ -39,6 +42,9 @@ const (
AnnotationTags = "tailscale.com/tags"
AnnotationHostname = "tailscale.com/hostname"
// Annotations settable by users on ingresses.
AnnotationFunnel = "tailscale.com/funnel"
// Annotations set by the operator on pods to trigger restarts when the
// hostname or IP changes.
podAnnotationLastSetIP = "tailscale.com/operator-last-set-ip"
@ -50,7 +56,8 @@ type tailscaleSTSConfig struct {
ParentResourceUID string
ChildResourceLabels map[string]string
TargetIP string
ServeConfig *ipn.ServeConfig
TargetIP string
Hostname string
Tags []string // if empty, use defaultTags
@ -168,43 +175,57 @@ func (a *tailscaleSTSReconciler) createOrGetSecret(ctx context.Context, logger *
Labels: stsC.ChildResourceLabels,
},
}
alreadyExists := false
if err := a.Get(ctx, client.ObjectKeyFromObject(secret), secret); err == nil {
logger.Debugf("secret %s/%s already exists", secret.GetNamespace(), secret.GetName())
return secret.Name, nil
alreadyExists = true
} else if !apierrors.IsNotFound(err) {
return "", err
}
// Secret doesn't exist yet, create one. Initially it contains
// only the Tailscale authkey, but once Tailscale starts it'll
// also store the daemon state.
sts, err := getSingleObject[appsv1.StatefulSet](ctx, a.Client, a.operatorNamespace, stsC.ChildResourceLabels)
if err != nil {
return "", err
}
if sts != nil {
// StatefulSet exists, so we have already created the secret.
// If the secret is missing, they should delete the StatefulSet.
logger.Errorf("Tailscale proxy secret doesn't exist, but the corresponding StatefulSet %s/%s already does. Something is wrong, please delete the StatefulSet.", sts.GetNamespace(), sts.GetName())
return "", nil
}
// Create API Key secret which is going to be used by the statefulset
// to authenticate with Tailscale.
logger.Debugf("creating authkey for new tailscale proxy")
tags := stsC.Tags
if len(tags) == 0 {
tags = a.defaultTags
}
authKey, err := a.newAuthKey(ctx, tags)
if err != nil {
return "", err
}
if !alreadyExists {
// Secret doesn't exist yet, create one. Initially it contains
// only the Tailscale authkey, but once Tailscale starts it'll
// also store the daemon state.
sts, err := getSingleObject[appsv1.StatefulSet](ctx, a.Client, a.operatorNamespace, stsC.ChildResourceLabels)
if err != nil {
return "", err
}
if sts != nil {
// StatefulSet exists, so we have already created the secret.
// If the secret is missing, they should delete the StatefulSet.
logger.Errorf("Tailscale proxy secret doesn't exist, but the corresponding StatefulSet %s/%s already does. Something is wrong, please delete the StatefulSet.", sts.GetNamespace(), sts.GetName())
return "", nil
}
// Create API Key secret which is going to be used by the statefulset
// to authenticate with Tailscale.
logger.Debugf("creating authkey for new tailscale proxy")
tags := stsC.Tags
if len(tags) == 0 {
tags = a.defaultTags
}
authKey, err := a.newAuthKey(ctx, tags)
if err != nil {
return "", err
}
secret.StringData = map[string]string{
"authkey": authKey,
mak.Set(&secret.StringData, "authkey", authKey)
}
if err := a.Create(ctx, secret); err != nil {
return "", err
if stsC.ServeConfig != nil {
j, err := json.Marshal(stsC.ServeConfig)
if err != nil {
return "", err
}
mak.Set(&secret.StringData, "serve-config", string(j))
}
if alreadyExists {
if err := a.Update(ctx, secret); err != nil {
return "", err
}
} else {
if err := a.Create(ctx, secret); err != nil {
return "", err
}
}
return secret.Name, nil
}
@ -253,18 +274,23 @@ func (a *tailscaleSTSReconciler) newAuthKey(ctx context.Context, tags []string)
//go:embed manifests/proxy.yaml
var proxyYaml []byte
//go:embed manifests/userspace-proxy.yaml
var userspaceProxyYaml []byte
func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.SugaredLogger, sts *tailscaleSTSConfig, headlessSvc *corev1.Service, authKeySecret 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)
if sts.ServeConfig != nil {
if err := yaml.Unmarshal(userspaceProxyYaml, &ss); err != nil {
return nil, fmt.Errorf("failed to unmarshal proxy spec: %w", err)
}
} else {
if err := yaml.Unmarshal(proxyYaml, &ss); err != nil {
return nil, fmt.Errorf("failed to unmarshal proxy spec: %w", err)
}
}
container := &ss.Spec.Template.Spec.Containers[0]
container.Image = a.proxyImage
container.Env = append(container.Env,
corev1.EnvVar{
Name: "TS_DEST_IP",
Value: sts.TargetIP,
},
corev1.EnvVar{
Name: "TS_KUBE_SECRET",
Value: authKeySecret,
@ -273,6 +299,34 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
Name: "TS_HOSTNAME",
Value: sts.Hostname,
})
if sts.TargetIP != "" {
container.Env = append(container.Env, corev1.EnvVar{
Name: "TS_DEST_IP",
Value: sts.TargetIP,
})
} else if sts.ServeConfig != nil {
container.Env = append(container.Env, corev1.EnvVar{
Name: "TS_SERVE_CONFIG",
Value: "/etc/tailscaled/serve-config",
})
container.VolumeMounts = append(container.VolumeMounts, corev1.VolumeMount{
Name: "serve-config",
ReadOnly: true,
MountPath: "/etc/tailscaled",
})
ss.Spec.Template.Spec.Volumes = append(ss.Spec.Template.Spec.Volumes, corev1.Volume{
Name: "serve-config",
VolumeSource: corev1.VolumeSource{
Secret: &corev1.SecretVolumeSource{
SecretName: authKeySecret,
Items: []corev1.KeyToPath{{
Key: "serve-config",
Path: "serve-config",
}},
},
},
})
}
ss.ObjectMeta = metav1.ObjectMeta{
Name: headlessSvc.Name,
Namespace: a.operatorNamespace,

@ -24,7 +24,7 @@ type ServiceReconciler struct {
logger *zap.SugaredLogger
}
func childResourceLabels(parent *corev1.Service) map[string]string {
func childResourceLabels(name, ns, typ string) map[string]string {
// You might wonder why we're using owner references, since they seem to be
// built for exactly this. Unfortunately, Kubernetes does not support
// cross-namespace ownership, by design. This means we cannot make the
@ -33,9 +33,9 @@ func childResourceLabels(parent *corev1.Service) map[string]string {
// labels.
return map[string]string{
LabelManaged: "true",
LabelParentName: parent.GetName(),
LabelParentNamespace: parent.GetNamespace(),
LabelParentType: "svc",
LabelParentName: name,
LabelParentNamespace: ns,
LabelParentType: typ,
}
}
@ -72,7 +72,7 @@ func (a *ServiceReconciler) maybeCleanup(ctx context.Context, logger *zap.Sugare
return nil
}
if done, err := a.ssr.Cleanup(ctx, logger, childResourceLabels(svc)); err != nil {
if done, err := a.ssr.Cleanup(ctx, logger, childResourceLabels(svc.Name, svc.Namespace, "svc")); err != nil {
return fmt.Errorf("failed to cleanup: %w", err)
} else if !done {
logger.Debugf("cleanup not done yet, waiting for next reconcile")
@ -114,7 +114,7 @@ func (a *ServiceReconciler) maybeProvision(ctx context.Context, logger *zap.Suga
return fmt.Errorf("failed to add finalizer: %w", err)
}
}
crl := childResourceLabels(svc)
crl := childResourceLabels(svc.Name, svc.Namespace, "svc")
var tags []string
if tstr, ok := svc.Annotations[AnnotationTags]; ok {
tags = strings.Split(tstr, ",")

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