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tailscale/cmd/k8s-operator/connector.go

261 lines
9.6 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build !plan9
package main
import (
"context"
"fmt"
"net/netip"
"slices"
"sync"
"time"
"github.com/pkg/errors"
"go.uber.org/zap"
xslices "golang.org/x/exp/slices"
corev1 "k8s.io/api/core/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"
tsoperator "tailscale.com/k8s-operator"
tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
"tailscale.com/tstime"
"tailscale.com/util/clientmetric"
"tailscale.com/util/set"
)
const (
reasonConnectorCreationFailed = "ConnectorCreationFailed"
reasonConnectorCreated = "ConnectorCreated"
reasonConnectorCleanupFailed = "ConnectorCleanupFailed"
reasonConnectorCleanupInProgress = "ConnectorCleanupInProgress"
reasonConnectorInvalid = "ConnectorInvalid"
messageConnectorCreationFailed = "Failed creating Connector: %v"
messageConnectorInvalid = "Connector is invalid: %v"
shortRequeue = time.Second * 5
)
type ConnectorReconciler struct {
client.Client
recorder record.EventRecorder
ssr *tailscaleSTSReconciler
logger *zap.SugaredLogger
tsnamespace string
clock tstime.Clock
mu sync.Mutex // protects following
subnetRouters set.Slice[types.UID] // for subnet routers gauge
exitNodes set.Slice[types.UID] // for exit nodes gauge
}
var (
// gaugeConnectorResources tracks the overall number of Connectors currently managed by this operator instance.
gaugeConnectorResources = clientmetric.NewGauge("k8s_connector_resources")
// gaugeConnectorSubnetRouterResources tracks the number of Connectors managed by this operator instance that are subnet routers.
gaugeConnectorSubnetRouterResources = clientmetric.NewGauge("k8s_connector_subnetrouter_resources")
// gaugeConnectorExitNodeResources tracks the number of Connectors currently managed by this operator instance that are exit nodes.
gaugeConnectorExitNodeResources = clientmetric.NewGauge("k8s_connector_exitnode_resources")
)
func (a *ConnectorReconciler) Reconcile(ctx context.Context, req reconcile.Request) (res reconcile.Result, err error) {
logger := a.logger.With("Connector", req.Name)
logger.Debugf("starting reconcile")
defer logger.Debugf("reconcile finished")
cn := new(tsapi.Connector)
err = a.Get(ctx, req.NamespacedName, cn)
if apierrors.IsNotFound(err) {
logger.Debugf("Connector not found, assuming it was deleted")
return reconcile.Result{}, nil
} else if err != nil {
return reconcile.Result{}, fmt.Errorf("failed to get tailscale.com Connector: %w", err)
}
if !cn.DeletionTimestamp.IsZero() {
logger.Debugf("Connector is being deleted or should not be exposed, cleaning up resources")
ix := xslices.Index(cn.Finalizers, FinalizerName)
if ix < 0 {
logger.Debugf("no finalizer, nothing to do")
return reconcile.Result{}, nil
}
if done, err := a.maybeCleanupConnector(ctx, logger, cn); err != nil {
return reconcile.Result{}, err
} else if !done {
logger.Debugf("Connector resource cleanup not yet finished, will retry...")
return reconcile.Result{RequeueAfter: shortRequeue}, nil
}
cn.Finalizers = append(cn.Finalizers[:ix], cn.Finalizers[ix+1:]...)
if err := a.Update(ctx, cn); err != nil {
return reconcile.Result{}, err
}
logger.Infof("Connector resources cleaned up")
return reconcile.Result{}, nil
}
oldCnStatus := cn.Status.DeepCopy()
setStatus := func(cn *tsapi.Connector, conditionType tsapi.ConnectorConditionType, status metav1.ConditionStatus, reason, message string) (reconcile.Result, error) {
tsoperator.SetConnectorCondition(cn, tsapi.ConnectorReady, status, reason, message, cn.Generation, a.clock, logger)
if !apiequality.Semantic.DeepEqual(oldCnStatus, cn.Status) {
// An error encountered here should get returned by the Reconcile function.
if updateErr := a.Client.Status().Update(ctx, cn); updateErr != nil {
err = errors.Wrap(err, updateErr.Error())
}
}
return res, err
}
if !slices.Contains(cn.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("ensuring Connector is set up")
cn.Finalizers = append(cn.Finalizers, FinalizerName)
if err := a.Update(ctx, cn); err != nil {
logger.Errorf("error adding finalizer: %w", err)
return setStatus(cn, tsapi.ConnectorReady, metav1.ConditionFalse, reasonConnectorCreationFailed, reasonConnectorCreationFailed)
}
}
if err := a.validate(cn); err != nil {
logger.Errorf("error validating Connector spec: %w", err)
message := fmt.Sprintf(messageConnectorInvalid, err)
a.recorder.Eventf(cn, corev1.EventTypeWarning, reasonConnectorInvalid, message)
return setStatus(cn, tsapi.ConnectorReady, metav1.ConditionFalse, reasonConnectorInvalid, message)
}
if err = a.maybeProvisionConnector(ctx, logger, cn); err != nil {
logger.Errorf("error creating Connector resources: %w", err)
message := fmt.Sprintf(messageConnectorCreationFailed, err)
a.recorder.Eventf(cn, corev1.EventTypeWarning, reasonConnectorCreationFailed, message)
return setStatus(cn, tsapi.ConnectorReady, metav1.ConditionFalse, reasonConnectorCreationFailed, message)
}
logger.Info("Connector resources synced")
cn.Status.IsExitNode = cn.Spec.ExitNode
if cn.Spec.SubnetRouter != nil {
cn.Status.SubnetRoutes = cn.Spec.SubnetRouter.AdvertiseRoutes.Stringify()
return setStatus(cn, tsapi.ConnectorReady, metav1.ConditionTrue, reasonConnectorCreated, reasonConnectorCreated)
}
cn.Status.SubnetRoutes = ""
return setStatus(cn, tsapi.ConnectorReady, metav1.ConditionTrue, reasonConnectorCreated, reasonConnectorCreated)
}
// maybeProvisionConnector ensures that any new resources required for this
// Connector instance are deployed to the cluster.
func (a *ConnectorReconciler) maybeProvisionConnector(ctx context.Context, logger *zap.SugaredLogger, cn *tsapi.Connector) error {
hostname := cn.Name + "-connector"
if cn.Spec.Hostname != "" {
hostname = string(cn.Spec.Hostname)
}
crl := childResourceLabels(cn.Name, a.tsnamespace, "connector")
sts := &tailscaleSTSConfig{
ParentResourceName: cn.Name,
ParentResourceUID: string(cn.UID),
Hostname: hostname,
ChildResourceLabels: crl,
Tags: cn.Spec.Tags.Stringify(),
Connector: &connector{
isExitNode: cn.Spec.ExitNode,
},
}
if cn.Spec.SubnetRouter != nil && len(cn.Spec.SubnetRouter.AdvertiseRoutes) > 0 {
sts.Connector.routes = cn.Spec.SubnetRouter.AdvertiseRoutes.Stringify()
}
a.mu.Lock()
if sts.Connector.isExitNode {
a.exitNodes.Add(cn.UID)
} else {
a.exitNodes.Remove(cn.UID)
}
if sts.Connector.routes != "" {
a.subnetRouters.Add(cn.GetUID())
} else {
a.subnetRouters.Remove(cn.GetUID())
}
a.mu.Unlock()
gaugeConnectorSubnetRouterResources.Set(int64(a.subnetRouters.Len()))
gaugeConnectorExitNodeResources.Set(int64(a.exitNodes.Len()))
var connectors set.Slice[types.UID]
connectors.AddSlice(a.exitNodes.Slice())
connectors.AddSlice(a.subnetRouters.Slice())
gaugeConnectorResources.Set(int64(connectors.Len()))
_, err := a.ssr.Provision(ctx, logger, sts)
return err
}
func (a *ConnectorReconciler) maybeCleanupConnector(ctx context.Context, logger *zap.SugaredLogger, cn *tsapi.Connector) (bool, error) {
if done, err := a.ssr.Cleanup(ctx, logger, childResourceLabels(cn.Name, a.tsnamespace, "connector")); err != nil {
return false, fmt.Errorf("failed to cleanup Connector resources: %w", err)
} else if !done {
logger.Debugf("Connector cleanup not done yet, waiting for next reconcile")
return false, nil
}
// 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("cleaned up Connector resources")
a.mu.Lock()
a.subnetRouters.Remove(cn.UID)
a.exitNodes.Remove(cn.UID)
a.mu.Unlock()
gaugeConnectorExitNodeResources.Set(int64(a.exitNodes.Len()))
gaugeConnectorSubnetRouterResources.Set(int64(a.subnetRouters.Len()))
var connectors set.Slice[types.UID]
connectors.AddSlice(a.exitNodes.Slice())
connectors.AddSlice(a.subnetRouters.Slice())
gaugeConnectorResources.Set(int64(connectors.Len()))
return true, nil
}
func (a *ConnectorReconciler) validate(cn *tsapi.Connector) error {
// Connector fields are already validated at apply time with CEL validation
// on custom resource fields. The checks here are a backup in case the
// CEL validation breaks without us noticing.
if !(cn.Spec.SubnetRouter != nil || cn.Spec.ExitNode) {
return errors.New("invalid spec: a Connector must expose subnet routes or act as an exit node (or both)")
}
if cn.Spec.SubnetRouter == nil {
return nil
}
return validateSubnetRouter(cn.Spec.SubnetRouter)
}
func validateSubnetRouter(sb *tsapi.SubnetRouter) error {
if len(sb.AdvertiseRoutes) < 1 {
return errors.New("invalid subnet router spec: no routes defined")
}
var err error
for _, route := range sb.AdvertiseRoutes {
pfx, e := netip.ParsePrefix(string(route))
if e != nil {
err = errors.Wrap(err, fmt.Sprintf("route %s is invalid: %v", route, err))
continue
}
if pfx.Masked() != pfx {
err = errors.Wrap(err, fmt.Sprintf("route %s has non-address bits set; expected %s", pfx, pfx.Masked()))
}
}
return err
}