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tailscale/cmd/k8s-operator/operator.go

335 lines
11 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build !plan9
// tailscale-operator provides a way to expose services running in a Kubernetes
// cluster to your Tailnet.
package main
import (
"context"
"os"
"regexp"
"strings"
"time"
"github.com/go-logr/zapr"
"go.uber.org/zap"
"go.uber.org/zap/zapcore"
"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"
"sigs.k8s.io/controller-runtime/pkg/cache"
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/client/config"
"sigs.k8s.io/controller-runtime/pkg/handler"
logf "sigs.k8s.io/controller-runtime/pkg/log"
kzap "sigs.k8s.io/controller-runtime/pkg/log/zap"
"sigs.k8s.io/controller-runtime/pkg/manager"
"sigs.k8s.io/controller-runtime/pkg/manager/signals"
"sigs.k8s.io/controller-runtime/pkg/reconcile"
"tailscale.com/client/tailscale"
"tailscale.com/hostinfo"
"tailscale.com/ipn"
"tailscale.com/ipn/store/kubestore"
"tailscale.com/tsnet"
"tailscale.com/types/logger"
"tailscale.com/version"
)
//go:generate go run tailscale.com/cmd/k8s-operator/generate
func main() {
// Required to use our client API. We're fine with the instability since the
// client lives in the same repo as this code.
tailscale.I_Acknowledge_This_API_Is_Unstable = true
var (
tsNamespace = defaultEnv("OPERATOR_NAMESPACE", "")
tslogging = defaultEnv("OPERATOR_LOGGING", "info")
image = defaultEnv("PROXY_IMAGE", "tailscale/tailscale:latest")
priorityClassName = defaultEnv("PROXY_PRIORITY_CLASS_NAME", "")
tags = defaultEnv("PROXY_TAGS", "tag:k8s")
tsFirewallMode = defaultEnv("PROXY_FIREWALL_MODE", "")
)
var opts []kzap.Opts
switch tslogging {
case "info":
opts = append(opts, kzap.Level(zapcore.InfoLevel))
case "debug":
opts = append(opts, kzap.Level(zapcore.DebugLevel))
case "dev":
opts = append(opts, kzap.UseDevMode(true), kzap.Level(zapcore.DebugLevel))
}
zlog := kzap.NewRaw(opts...).Sugar()
logf.SetLogger(zapr.NewLogger(zlog.Desugar()))
// The operator can run either as a plain operator or it can
// additionally act as api-server proxy
// https://tailscale.com/kb/1236/kubernetes-operator/?q=kubernetes#accessing-the-kubernetes-control-plane-using-an-api-server-proxy.
mode := parseAPIProxyMode()
if mode == apiserverProxyModeDisabled {
hostinfo.SetApp("k8s-operator")
} else {
hostinfo.SetApp("k8s-operator-proxy")
}
s, tsClient := initTSNet(zlog)
defer s.Close()
restConfig := config.GetConfigOrDie()
maybeLaunchAPIServerProxy(zlog, restConfig, s, mode)
runReconcilers(zlog, s, tsNamespace, restConfig, tsClient, image, priorityClassName, tags, tsFirewallMode)
}
// initTSNet initializes the tsnet.Server and logs in to Tailscale. It uses the
// CLIENT_ID_FILE and CLIENT_SECRET_FILE environment variables to authenticate
// with Tailscale.
func initTSNet(zlog *zap.SugaredLogger) (*tsnet.Server, *tailscale.Client) {
var (
clientIDPath = defaultEnv("CLIENT_ID_FILE", "")
clientSecretPath = defaultEnv("CLIENT_SECRET_FILE", "")
hostname = defaultEnv("OPERATOR_HOSTNAME", "tailscale-operator")
kubeSecret = defaultEnv("OPERATOR_SECRET", "")
operatorTags = defaultEnv("OPERATOR_INITIAL_TAGS", "tag:k8s-operator")
)
startlog := zlog.Named("startup")
if clientIDPath == "" || clientSecretPath == "" {
startlog.Fatalf("CLIENT_ID_FILE and CLIENT_SECRET_FILE must be set")
}
clientID, err := os.ReadFile(clientIDPath)
if err != nil {
startlog.Fatalf("reading client ID %q: %v", clientIDPath, err)
}
clientSecret, err := os.ReadFile(clientSecretPath)
if err != nil {
startlog.Fatalf("reading client secret %q: %v", clientSecretPath, err)
}
credentials := clientcredentials.Config{
ClientID: string(clientID),
ClientSecret: string(clientSecret),
TokenURL: "https://login.tailscale.com/api/v2/oauth/token",
}
tsClient := tailscale.NewClient("-", nil)
tsClient.HTTPClient = credentials.Client(context.Background())
s := &tsnet.Server{
Hostname: hostname,
Logf: zlog.Named("tailscaled").Debugf,
}
if kubeSecret != "" {
st, err := kubestore.New(logger.Discard, kubeSecret)
if err != nil {
startlog.Fatalf("creating kube store: %v", err)
}
s.Store = st
}
if err := s.Start(); err != nil {
startlog.Fatalf("starting tailscale server: %v", err)
}
lc, err := s.LocalClient()
if err != nil {
startlog.Fatalf("getting local client: %v", err)
}
ctx := context.Background()
loginDone := false
machineAuthShown := false
waitOnline:
for {
startlog.Debugf("querying tailscaled status")
st, err := lc.StatusWithoutPeers(ctx)
if err != nil {
startlog.Fatalf("getting status: %v", err)
}
switch st.BackendState {
case "Running":
break waitOnline
case "NeedsLogin":
if loginDone {
break
}
caps := tailscale.KeyCapabilities{
Devices: tailscale.KeyDeviceCapabilities{
Create: tailscale.KeyDeviceCreateCapabilities{
Reusable: false,
Preauthorized: true,
Tags: strings.Split(operatorTags, ","),
},
},
}
authkey, _, err := tsClient.CreateKey(ctx, caps)
if err != nil {
startlog.Fatalf("creating operator authkey: %v", err)
}
if err := lc.Start(ctx, ipn.Options{
AuthKey: authkey,
}); err != nil {
startlog.Fatalf("starting tailscale: %v", err)
}
if err := lc.StartLoginInteractive(ctx); err != nil {
startlog.Fatalf("starting login: %v", err)
}
startlog.Debugf("requested login by authkey")
loginDone = true
case "NeedsMachineAuth":
if !machineAuthShown {
startlog.Infof("Machine approval required, please visit the admin panel to approve")
machineAuthShown = true
}
default:
startlog.Debugf("waiting for tailscale to start: %v", st.BackendState)
}
time.Sleep(time.Second)
}
return s, tsClient
}
// runReconcilers starts the controller-runtime manager and registers the
// ServiceReconciler. It blocks forever.
func runReconcilers(zlog *zap.SugaredLogger, s *tsnet.Server, tsNamespace string, restConfig *rest.Config, tsClient *tailscale.Client, image, priorityClassName, tags, tsFirewallMode string) {
var (
isDefaultLoadBalancer = defaultBool("OPERATOR_DEFAULT_LOAD_BALANCER", false)
)
startlog := zlog.Named("startReconcilers")
// For secrets and statefulsets, we only get permission to touch the objects
// in the controller's own namespace. This cannot be expressed by
// .Watches(...) below, instead you have to add a per-type field selector to
// the cache that sits a few layers below the builder stuff, which will
// implicitly filter what parts of the world the builder code gets to see at
// all.
nsFilter := cache.ByObject{
Field: client.InNamespace(tsNamespace).AsSelector(),
}
mgr, err := manager.New(restConfig, manager.Options{
Cache: cache.Options{
ByObject: map[client.Object]cache.ByObject{
&corev1.Secret{}: nsFilter,
&appsv1.StatefulSet{}: nsFilter,
},
},
})
if err != nil {
startlog.Fatalf("could not create manager: %v", err)
}
svcFilter := handler.EnqueueRequestsFromMapFunc(serviceHandler)
svcChildFilter := handler.EnqueueRequestsFromMapFunc(managedResourceHandlerForType("svc"))
eventRecorder := mgr.GetEventRecorderFor("tailscale-operator")
ssr := &tailscaleSTSReconciler{
Client: mgr.GetClient(),
tsnetServer: s,
tsClient: tsClient,
defaultTags: strings.Split(tags, ","),
operatorNamespace: tsNamespace,
proxyImage: image,
proxyPriorityClassName: priorityClassName,
tsFirewallMode: tsFirewallMode,
}
err = builder.
ControllerManagedBy(mgr).
Named("service-reconciler").
Watches(&corev1.Service{}, svcFilter).
Watches(&appsv1.StatefulSet{}, svcChildFilter).
Watches(&corev1.Secret{}, svcChildFilter).
Complete(&ServiceReconciler{
ssr: ssr,
Client: mgr.GetClient(),
logger: zlog.Named("service-reconciler"),
isDefaultLoadBalancer: isDefaultLoadBalancer,
recorder: eventRecorder,
})
if err != nil {
startlog.Fatalf("could not create controller: %v", err)
}
ingressChildFilter := handler.EnqueueRequestsFromMapFunc(managedResourceHandlerForType("ingress"))
err = builder.
ControllerManagedBy(mgr).
For(&networkingv1.Ingress{}).
Watches(&appsv1.StatefulSet{}, ingressChildFilter).
Watches(&corev1.Secret{}, ingressChildFilter).
Watches(&corev1.Service{}, ingressChildFilter).
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 {
startlog.Fatalf("could not start manager: %v", err)
}
}
type tsClient interface {
CreateKey(ctx context.Context, caps tailscale.KeyCapabilities) (string, *tailscale.Key, error)
DeleteDevice(ctx context.Context, nodeStableID string) error
}
func isManagedResource(o client.Object) bool {
ls := o.GetLabels()
return ls[LabelManaged] == "true"
}
func isManagedByType(o client.Object, typ string) bool {
ls := o.GetLabels()
return isManagedResource(o) && ls[LabelParentType] == typ
}
func parentFromObjectLabels(o client.Object) types.NamespacedName {
ls := o.GetLabels()
return types.NamespacedName{
Namespace: ls[LabelParentNamespace],
Name: ls[LabelParentName],
}
}
func managedResourceHandlerForType(typ string) handler.MapFunc {
return func(_ context.Context, o client.Object) []reconcile.Request {
if !isManagedByType(o, typ) {
return nil
}
return []reconcile.Request{
{NamespacedName: parentFromObjectLabels(o)},
}
}
}
func serviceHandler(_ context.Context, o client.Object) []reconcile.Request {
if isManagedByType(o, "svc") {
// If this is a Service managed by a Service we want to enqueue its parent
return []reconcile.Request{{NamespacedName: parentFromObjectLabels(o)}}
}
if isManagedResource(o) {
// If this is a Servce managed by a resource that is not a Service, we leave it alone
return nil
}
// If this is not a managed Service we want to enqueue it
return []reconcile.Request{
{
NamespacedName: types.NamespacedName{
Namespace: o.GetNamespace(),
Name: o.GetName(),
},
},
}
}
// isMagicDNSName reports whether name is a full tailnet node FQDN (with or
// without final dot).
func isMagicDNSName(name string) bool {
validMagicDNSName := regexp.MustCompile(`^[a-zA-Z0-9-]+\.[a-zA-Z0-9-]+\.ts\.net\.?$`)
return validMagicDNSName.MatchString(name)
}