tailscale/cmd/k8s-operator/proxygroup.go

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// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build !plan9
package main
import (
"context"
"crypto/sha256"
"encoding/json"
"fmt"
"net/http"
"slices"
"sync"
"github.com/pkg/errors"
"go.uber.org/zap"
xslices "golang.org/x/exp/slices"
appsv1 "k8s.io/api/apps/v1"
corev1 "k8s.io/api/core/v1"
rbacv1 "k8s.io/api/rbac/v1"
apiequality "k8s.io/apimachinery/pkg/api/equality"
apierrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"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/client/tailscale"
"tailscale.com/ipn"
tsoperator "tailscale.com/k8s-operator"
tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
"tailscale.com/kube/kubetypes"
"tailscale.com/tailcfg"
"tailscale.com/tstime"
"tailscale.com/types/ptr"
"tailscale.com/util/clientmetric"
"tailscale.com/util/mak"
"tailscale.com/util/set"
)
const (
reasonProxyGroupCreationFailed = "ProxyGroupCreationFailed"
reasonProxyGroupCreated = "ProxyGroupCreated"
reasonProxyGroupCreating = "ProxyGroupCreating"
reasonProxyGroupInvalid = "ProxyGroupInvalid"
)
var gaugeProxyGroupResources = clientmetric.NewGauge(kubetypes.MetricProxyGroupCount)
// ProxyGroupReconciler syncs ProxyGroup statefulsets with their definition in
// ProxyGroup CRs.
type ProxyGroupReconciler struct {
client.Client
l *zap.SugaredLogger
recorder record.EventRecorder
clock tstime.Clock
tsNamespace string
tsClient tsClient
mu sync.Mutex // protects following
proxyGroups set.Slice[types.UID] // for proxygroups gauge
}
func (r *ProxyGroupReconciler) logger(name string) *zap.SugaredLogger {
return r.l.With("ProxyGroup", name)
}
func (r *ProxyGroupReconciler) Reconcile(ctx context.Context, req reconcile.Request) (_ reconcile.Result, err error) {
logger := r.logger(req.Name)
logger.Debugf("starting reconcile")
defer logger.Debugf("reconcile finished")
pg := new(tsapi.ProxyGroup)
err = r.Get(ctx, req.NamespacedName, pg)
if apierrors.IsNotFound(err) {
logger.Debugf("ProxyGroup not found, assuming it was deleted")
return reconcile.Result{}, nil
} else if err != nil {
return reconcile.Result{}, fmt.Errorf("failed to get tailscale.com ProxyGroup: %w", err)
}
if markedForDeletion(pg) {
logger.Debugf("ProxyGroup is being deleted, cleaning up resources")
ix := xslices.Index(pg.Finalizers, FinalizerName)
if ix < 0 {
logger.Debugf("no finalizer, nothing to do")
return reconcile.Result{}, nil
}
if done, err := r.maybeCleanup(ctx, pg); err != nil {
return reconcile.Result{}, err
} else if !done {
logger.Debugf("ProxyGroup resource cleanup not yet finished, will retry...")
return reconcile.Result{RequeueAfter: shortRequeue}, nil
}
pg.Finalizers = slices.Delete(pg.Finalizers, ix, ix+1)
if err := r.Update(ctx, pg); err != nil {
return reconcile.Result{}, err
}
return reconcile.Result{}, nil
}
oldPGStatus := pg.Status.DeepCopy()
setStatusReady := func(pg *tsapi.ProxyGroup, status metav1.ConditionStatus, reason, message string) (reconcile.Result, error) {
tsoperator.SetProxyGroupCondition(pg, tsapi.ProxyGroupReady, status, reason, message, pg.Generation, r.clock, logger)
if !apiequality.Semantic.DeepEqual(oldPGStatus, pg.Status) {
// An error encountered here should get returned by the Reconcile function.
if updateErr := r.Client.Status().Update(ctx, pg); updateErr != nil {
err = errors.Wrap(err, updateErr.Error())
}
}
return reconcile.Result{}, err
}
if !slices.Contains(pg.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 log that the high level, multi-reconcile
// operation is underway.
logger.Infof("ensuring ProxyGroup is set up")
pg.Finalizers = append(pg.Finalizers, FinalizerName)
if err := r.Update(ctx, pg); err != nil {
logger.Errorf("error adding finalizer: %w", err)
return setStatusReady(pg, metav1.ConditionFalse, reasonProxyGroupCreationFailed, reasonProxyGroupCreationFailed)
}
}
if err := r.validate(pg); err != nil {
logger.Errorf("error validating ProxyGroup spec: %w", err)
message := fmt.Sprintf("ProxyGroup is invalid: %s", err)
r.recorder.Eventf(pg, corev1.EventTypeWarning, reasonProxyGroupInvalid, message)
return setStatusReady(pg, metav1.ConditionFalse, reasonProxyGroupInvalid, message)
}
if err = r.maybeProvision(ctx, pg); err != nil {
logger.Errorf("error creating ProxyGroup resources: %w", err)
message := fmt.Sprintf("failed creating ProxyGroup: %s", err)
r.recorder.Eventf(pg, corev1.EventTypeWarning, reasonProxyGroupCreationFailed, message)
return setStatusReady(pg, metav1.ConditionFalse, reasonProxyGroupCreationFailed, message)
}
desiredReplicas := int(pgReplicas(pg))
if len(pg.Status.Devices) < desiredReplicas {
message := fmt.Sprintf("%d/%d ProxyGroup pods running", len(pg.Status.Devices), desiredReplicas)
logger.Debug(message)
return setStatusReady(pg, metav1.ConditionFalse, reasonProxyGroupCreating, message)
}
if len(pg.Status.Devices) > desiredReplicas {
message := fmt.Sprintf("waiting for %d ProxyGroup pods to shut down", len(pg.Status.Devices)-desiredReplicas)
logger.Debug(message)
return setStatusReady(pg, metav1.ConditionFalse, reasonProxyGroupCreating, message)
}
logger.Info("ProxyGroup resources synced")
return setStatusReady(pg, metav1.ConditionTrue, reasonProxyGroupCreated, reasonProxyGroupCreated)
}
func (r *ProxyGroupReconciler) maybeProvision(ctx context.Context, pg *tsapi.ProxyGroup) error {
logger := r.logger(pg.Name)
r.mu.Lock()
r.proxyGroups.Add(pg.UID)
gaugeProxyGroupResources.Set(int64(r.proxyGroups.Len()))
r.mu.Unlock()
var proxyClass *tsapi.ProxyClass
if pg.Spec.ProxyClass != "" {
proxyClass = new(tsapi.ProxyClass)
if err := r.Get(ctx, types.NamespacedName{Name: pg.Spec.ProxyClass}, proxyClass); err != nil {
return fmt.Errorf("failed to get ProxyClass: %w", err)
}
if !tsoperator.ProxyClassIsReady(proxyClass) {
logger.Infof("ProxyClass %s specified for the proxy, but it is not (yet) in a ready state, waiting...", pg.Spec.ProxyClass)
return nil
}
}
cfgHash, err := r.ensureConfigSecretsCreated(ctx, pg, proxyClass)
if err != nil {
return fmt.Errorf("error creating secrets: %w", err)
}
// State secrets are precreated so we can use the ProxyGroup CR as their owner ref.
stateSecrets := pgStateSecrets(pg, r.tsNamespace)
for _, sec := range stateSecrets {
if _, err := createOrUpdate(ctx, r.Client, r.tsNamespace, sec, func(s *corev1.Secret) {
s.ObjectMeta.Labels = sec.ObjectMeta.Labels
s.ObjectMeta.Annotations = sec.ObjectMeta.Annotations
s.ObjectMeta.OwnerReferences = sec.ObjectMeta.OwnerReferences
}); err != nil {
return fmt.Errorf("error creating state Secret: %w", err)
}
}
sa := pgServiceAccount(pg, r.tsNamespace)
if _, err := createOrUpdate(ctx, r.Client, r.tsNamespace, sa, func(s *corev1.ServiceAccount) {
s.ObjectMeta.Labels = sa.ObjectMeta.Labels
s.ObjectMeta.Annotations = sa.ObjectMeta.Annotations
s.ObjectMeta.OwnerReferences = sa.ObjectMeta.OwnerReferences
}); err != nil {
return fmt.Errorf("error creating ServiceAccount: %w", err)
}
role := pgRole(pg, r.tsNamespace)
if _, err := createOrUpdate(ctx, r.Client, r.tsNamespace, role, func(r *rbacv1.Role) {
r.ObjectMeta.Labels = role.ObjectMeta.Labels
r.ObjectMeta.Annotations = role.ObjectMeta.Annotations
r.ObjectMeta.OwnerReferences = role.ObjectMeta.OwnerReferences
r.Rules = role.Rules
}); err != nil {
return fmt.Errorf("error creating Role: %w", err)
}
roleBinding := pgRoleBinding(pg, r.tsNamespace)
if _, err := createOrUpdate(ctx, r.Client, r.tsNamespace, roleBinding, func(r *rbacv1.RoleBinding) {
r.ObjectMeta.Labels = roleBinding.ObjectMeta.Labels
r.ObjectMeta.Annotations = roleBinding.ObjectMeta.Annotations
r.ObjectMeta.OwnerReferences = roleBinding.ObjectMeta.OwnerReferences
r.RoleRef = roleBinding.RoleRef
r.Subjects = roleBinding.Subjects
}); err != nil {
return fmt.Errorf("error creating RoleBinding: %w", err)
}
ss := pgStatefulSet(pg, r.tsNamespace, cfgHash)
ss = applyProxyClassToStatefulSet(proxyClass, ss, nil, logger)
if _, err := createOrUpdate(ctx, r.Client, r.tsNamespace, ss, func(s *appsv1.StatefulSet) {
s.ObjectMeta.Labels = ss.ObjectMeta.Labels
s.ObjectMeta.Annotations = ss.ObjectMeta.Annotations
s.ObjectMeta.OwnerReferences = ss.ObjectMeta.OwnerReferences
s.Spec = ss.Spec
}); err != nil {
return fmt.Errorf("error creating StatefulSet: %w", err)
}
if err := r.cleanupDanglingResources(ctx, pg); err != nil {
return fmt.Errorf("error cleaning up dangling resources: %w", err)
}
devices, err := r.getDeviceInfo(ctx, pg)
if err != nil {
return fmt.Errorf("failed to get device info: %w", err)
}
pg.Status.Devices = devices
return nil
}
// cleanupDanglingResources ensures we don't leak config secrets, state secrets, and
// tailnet devices when the number of replicas specified is reduced.
func (r *ProxyGroupReconciler) cleanupDanglingResources(ctx context.Context, pg *tsapi.ProxyGroup) error {
logger := r.logger(pg.Name)
metadata, err := r.getNodeMetadata(ctx, pg)
if err != nil {
return err
}
for _, m := range metadata {
if m.ordinal+1 <= int(pgReplicas(pg)) {
continue
}
// Dangling resource, delete the config + state Secrets, as well as
// deleting the device from the tailnet.
if err := r.deleteTailnetDevice(ctx, m.tsID, logger); err != nil {
return err
}
if err := r.Delete(ctx, m.stateSecret); err != nil {
if !apierrors.IsNotFound(err) {
return fmt.Errorf("error deleting state Secret %s: %w", m.stateSecret.Name, err)
}
logger.Debugf("deleted state Secret %s but got not found", m.stateSecret.Name)
}
configSecret := m.stateSecret.DeepCopy()
configSecret.Name += "-config"
if err := r.Delete(ctx, configSecret); err != nil {
if !apierrors.IsNotFound(err) {
return fmt.Errorf("error deleting config Secret %s: %w", configSecret.Name, err)
}
logger.Debugf("deleted config Secret %s but got not found", configSecret.Name)
}
}
return nil
}
// maybeCleanup just deletes the device from the tailnet. All the kubernetes
// resources linked to a ProxyGroup will get cleaned up via owner references
// (which we can use because they are all in the same namespace).
func (r *ProxyGroupReconciler) maybeCleanup(ctx context.Context, pg *tsapi.ProxyGroup) (bool, error) {
logger := r.logger(pg.Name)
metadata, err := r.getNodeMetadata(ctx, pg)
if err != nil {
return false, err
}
for _, m := range metadata {
if err := r.deleteTailnetDevice(ctx, m.tsID, logger); err != nil {
return false, err
}
}
logger.Infof("cleaned up ProxyGroup resources")
r.mu.Lock()
r.proxyGroups.Remove(pg.UID)
gaugeProxyGroupResources.Set(int64(r.proxyGroups.Len()))
r.mu.Unlock()
return true, nil
}
func (r *ProxyGroupReconciler) deleteTailnetDevice(ctx context.Context, id tailcfg.StableNodeID, logger *zap.SugaredLogger) error {
logger.Debugf("deleting device %s from control", string(id))
if err := r.tsClient.DeleteDevice(ctx, string(id)); err != nil {
errResp := &tailscale.ErrResponse{}
if ok := errors.As(err, errResp); ok && errResp.Status == http.StatusNotFound {
logger.Debugf("device %s not found, likely because it has already been deleted from control", string(id))
} else {
return fmt.Errorf("error deleting device: %w", err)
}
} else {
logger.Debugf("device %s deleted from control", string(id))
}
return nil
}
func (r *ProxyGroupReconciler) ensureConfigSecretsCreated(ctx context.Context, pg *tsapi.ProxyGroup, proxyClass *tsapi.ProxyClass) (hash string, err error) {
logger := r.logger(pg.Name)
var allConfigs []tailscaledConfigs
for i := range pgReplicas(pg) {
cfgSecret := &corev1.Secret{
ObjectMeta: metav1.ObjectMeta{
Name: fmt.Sprintf("%s-%d-config", pg.Name, i),
Namespace: r.tsNamespace,
Labels: secretLabels("proxygroup", pg.Name, "config"),
OwnerReferences: pgOwnerReference(pg),
},
}
var existingCfgSecret *corev1.Secret // unmodified copy of secret
if err := r.Get(ctx, client.ObjectKeyFromObject(cfgSecret), cfgSecret); err == nil {
logger.Debugf("secret %s/%s already exists", cfgSecret.GetNamespace(), cfgSecret.GetName())
existingCfgSecret = cfgSecret.DeepCopy()
} else if !apierrors.IsNotFound(err) {
return "", err
}
var authKey string
if existingCfgSecret == nil {
logger.Debugf("creating authkey for new ProxyGroup proxy")
tags := pg.Spec.Tags
if len(tags) == 0 {
tags = tsapi.Tags{"tag:k8s"}
}
authKey, err = newAuthKey(ctx, r.tsClient, tags.Stringify())
if err != nil {
return "", err
}
}
configs, err := pgTailscaledConfig(pg, proxyClass, i, authKey, existingCfgSecret)
if err != nil {
return "", fmt.Errorf("error creating tailscaled config: %w", err)
}
allConfigs = append(allConfigs, configs)
for cap, cfg := range configs {
cfgJSON, err := json.Marshal(cfg)
if err != nil {
return "", fmt.Errorf("error marshalling tailscaled config: %w", err)
}
mak.Set(&cfgSecret.StringData, tsoperator.TailscaledConfigFileName(cap), string(cfgJSON))
}
if existingCfgSecret != nil {
logger.Debugf("patching the existing ProxyGroup config Secret %s", cfgSecret.Name)
if err := r.Patch(ctx, cfgSecret, client.MergeFrom(existingCfgSecret)); err != nil {
return "", err
}
} else {
logger.Debugf("creating a new config Secret %s for the ProxyGroup", cfgSecret.Name)
if err := r.Create(ctx, cfgSecret); err != nil {
return "", err
}
}
}
sum := sha256.New()
b, err := json.Marshal(allConfigs)
if err != nil {
return "", err
}
if _, err := sum.Write(b); err != nil {
return "", err
}
return string(sum.Sum(nil)), nil
}
func pgTailscaledConfig(pg *tsapi.ProxyGroup, class *tsapi.ProxyClass, idx int32, authKey string, oldSecret *corev1.Secret) (tailscaledConfigs, error) {
conf := &ipn.ConfigVAlpha{
Version: "alpha0",
AcceptDNS: "false",
AcceptRoutes: "false", // AcceptRoutes defaults to true
Locked: "false",
Hostname: ptr.To(fmt.Sprintf("%s-%d", pg.Name, idx)),
}
if pg.Spec.HostnamePrefix != "" {
conf.Hostname = ptr.To(fmt.Sprintf("%s%d", pg.Spec.HostnamePrefix, idx))
}
if shouldAcceptRoutes(class) {
conf.AcceptRoutes = "true"
}
if authKey != "" {
conf.AuthKey = &authKey
} else if shouldRetainAuthKey(oldSecret) {
key, err := authKeyFromSecret(oldSecret)
if err != nil {
return nil, fmt.Errorf("error retrieving auth key from Secret: %w", err)
}
conf.AuthKey = key
}
capVerConfigs := make(map[tailcfg.CapabilityVersion]ipn.ConfigVAlpha)
capVerConfigs[95] = *conf
// legacy config should not contain NoStatefulFiltering field.
conf.NoStatefulFiltering.Clear()
capVerConfigs[94] = *conf
return capVerConfigs, nil
}
func (r *ProxyGroupReconciler) validate(_ *tsapi.ProxyGroup) error {
return nil
}
// getNodeMetadata gets metadata for all the pods owned by this ProxyGroup by
// querying their state Secrets. It may not return the same number of items as
// specified in the ProxyGroup spec if e.g. it is getting scaled up or down, or
// some pods have failed to write state.
func (r *ProxyGroupReconciler) getNodeMetadata(ctx context.Context, pg *tsapi.ProxyGroup) (metadata []nodeMetadata, _ error) {
// List all state secrets owned by this ProxyGroup.
secrets := &corev1.SecretList{}
if err := r.List(ctx, secrets, client.InNamespace(r.tsNamespace), client.MatchingLabels(secretLabels("proxygroup", pg.Name, "state"))); err != nil {
return nil, fmt.Errorf("failed to list state Secrets: %w", err)
}
for _, secret := range secrets.Items {
var ordinal int
if _, err := fmt.Sscanf(secret.Name, pg.Name+"-%d", &ordinal); err != nil {
return nil, fmt.Errorf("unexpected secret %s was labelled as owned by the ProxyGroup %s: %w", secret.Name, pg.Name, err)
}
id, dnsName, ok, err := getNodeMetadata(ctx, &secret)
if err != nil {
return nil, err
}
if !ok {
continue
}
metadata = append(metadata, nodeMetadata{
ordinal: ordinal,
stateSecret: &secret,
tsID: id,
dnsName: dnsName,
})
}
return metadata, nil
}
func (r *ProxyGroupReconciler) getDeviceInfo(ctx context.Context, pg *tsapi.ProxyGroup) (devices []tsapi.TailnetDevice, _ error) {
metadata, err := r.getNodeMetadata(ctx, pg)
if err != nil {
return nil, err
}
for _, m := range metadata {
device, ok, err := getDeviceInfo(ctx, r.tsClient, m.stateSecret)
if err != nil {
return nil, err
}
if !ok {
continue
}
devices = append(devices, tsapi.TailnetDevice{
Hostname: device.Hostname,
TailnetIPs: device.TailnetIPs,
})
}
return devices, nil
}
type nodeMetadata struct {
ordinal int
stateSecret *corev1.Secret
tsID tailcfg.StableNodeID
dnsName string
}