tailscale/cmd/k8s-operator/proxyclass.go
2024-07-17 14:34:56 +01:00

196 lines
7.6 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build !plan9
package main
import (
"context"
"fmt"
"slices"
"strings"
"sync"
dockerref "github.com/distribution/reference"
"go.uber.org/zap"
corev1 "k8s.io/api/core/v1"
apiequality "k8s.io/apimachinery/pkg/api/equality"
apierrors "k8s.io/apimachinery/pkg/api/errors"
apivalidation "k8s.io/apimachinery/pkg/api/validation"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
metavalidation "k8s.io/apimachinery/pkg/apis/meta/v1/validation"
"k8s.io/apimachinery/pkg/types"
"k8s.io/apimachinery/pkg/util/validation/field"
"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 (
reasonProxyClassInvalid = "ProxyClassInvalid"
reasonProxyClassValid = "ProxyClassValid"
reasonCustomTSEnvVar = "CustomTSEnvVar"
messageProxyClassInvalid = "ProxyClass is not valid: %v"
messageCustomTSEnvVar = "ProxyClass overrides the default value for %s env var for %s container. Running with custom values for Tailscale env vars is not recommended and might break in the future."
)
type ProxyClassReconciler struct {
client.Client
recorder record.EventRecorder
logger *zap.SugaredLogger
clock tstime.Clock
mu sync.Mutex // protects following
// managedProxyClasses is a set of all ProxyClass resources that we're currently
// managing. This is only used for metrics.
managedProxyClasses set.Slice[types.UID]
}
var (
// gaugeProxyClassResources tracks the number of ProxyClass resources
// that we're currently managing.
gaugeProxyClassResources = clientmetric.NewGauge("k8s_proxyclass_resources")
)
func (pcr *ProxyClassReconciler) Reconcile(ctx context.Context, req reconcile.Request) (res reconcile.Result, err error) {
logger := pcr.logger.With("ProxyClass", req.Name)
logger.Debugf("starting reconcile")
defer logger.Debugf("reconcile finished")
pc := new(tsapi.ProxyClass)
err = pcr.Get(ctx, req.NamespacedName, pc)
if apierrors.IsNotFound(err) {
logger.Debugf("ProxyClass not found, assuming it was deleted")
return reconcile.Result{}, nil
} else if err != nil {
return reconcile.Result{}, fmt.Errorf("failed to get tailscale.com ProxyClass: %w", err)
}
if !pc.DeletionTimestamp.IsZero() {
logger.Debugf("ProxyClass is being deleted")
return reconcile.Result{}, pcr.maybeCleanup(ctx, logger, pc)
}
// Add a finalizer so that we can ensure that metrics get updated when
// this ProxyClass is deleted.
if !slices.Contains(pc.Finalizers, FinalizerName) {
logger.Debugf("updating ProxyClass finalizers")
pc.Finalizers = append(pc.Finalizers, FinalizerName)
if err := pcr.Update(ctx, pc); err != nil {
return res, fmt.Errorf("failed to add finalizer: %w", err)
}
}
// Ensure this ProxyClass is tracked in metrics.
pcr.mu.Lock()
pcr.managedProxyClasses.Add(pc.UID)
gaugeProxyClassResources.Set(int64(pcr.managedProxyClasses.Len()))
pcr.mu.Unlock()
oldPCStatus := pc.Status.DeepCopy()
if errs := pcr.validate(pc); errs != nil {
msg := fmt.Sprintf(messageProxyClassInvalid, errs.ToAggregate().Error())
pcr.recorder.Event(pc, corev1.EventTypeWarning, reasonProxyClassInvalid, msg)
tsoperator.SetProxyClassCondition(pc, tsapi.ProxyClassready, metav1.ConditionFalse, reasonProxyClassInvalid, msg, pc.Generation, pcr.clock, logger)
} else {
tsoperator.SetProxyClassCondition(pc, tsapi.ProxyClassready, metav1.ConditionTrue, reasonProxyClassValid, reasonProxyClassValid, pc.Generation, pcr.clock, logger)
}
if !apiequality.Semantic.DeepEqual(oldPCStatus, pc.Status) {
if err := pcr.Client.Status().Update(ctx, pc); err != nil {
logger.Errorf("error updating ProxyClass status: %v", err)
return reconcile.Result{}, err
}
}
return reconcile.Result{}, nil
}
func (pcr *ProxyClassReconciler) validate(pc *tsapi.ProxyClass) (violations field.ErrorList) {
if sts := pc.Spec.StatefulSet; sts != nil {
if len(sts.Labels) > 0 {
if errs := metavalidation.ValidateLabels(sts.Labels, field.NewPath(".spec.statefulSet.labels")); errs != nil {
violations = append(violations, errs...)
}
}
if len(sts.Annotations) > 0 {
if errs := apivalidation.ValidateAnnotations(sts.Annotations, field.NewPath(".spec.statefulSet.annotations")); errs != nil {
violations = append(violations, errs...)
}
}
if pod := sts.Pod; pod != nil {
if len(pod.Labels) > 0 {
if errs := metavalidation.ValidateLabels(pod.Labels, field.NewPath(".spec.statefulSet.pod.labels")); errs != nil {
violations = append(violations, errs...)
}
}
if len(pod.Annotations) > 0 {
if errs := apivalidation.ValidateAnnotations(pod.Annotations, field.NewPath(".spec.statefulSet.pod.annotations")); errs != nil {
violations = append(violations, errs...)
}
}
if tc := pod.TailscaleContainer; tc != nil {
for _, e := range tc.Env {
if strings.HasPrefix(string(e.Name), "TS_") {
pcr.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
}
if strings.EqualFold(string(e.Name), "EXPERIMENTAL_TS_CONFIGFILE_PATH") {
pcr.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
}
if strings.EqualFold(string(e.Name), "EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS") {
pcr.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
}
}
if tc.Image != "" {
// Same validation as used by kubelet https://github.com/kubernetes/kubernetes/blob/release-1.30/pkg/kubelet/images/image_manager.go#L212
if _, err := dockerref.ParseNormalizedNamed(tc.Image); err != nil {
violations = append(violations, field.TypeInvalid(field.NewPath("spec", "statefulSet", "pod", "tailscaleContainer", "image"), tc.Image, err.Error()))
}
}
}
if tc := pod.TailscaleInitContainer; tc != nil {
if tc.Image != "" {
// Same validation as used by kubelet https://github.com/kubernetes/kubernetes/blob/release-1.30/pkg/kubelet/images/image_manager.go#L212
if _, err := dockerref.ParseNormalizedNamed(tc.Image); err != nil {
violations = append(violations, field.TypeInvalid(field.NewPath("spec", "statefulSet", "pod", "tailscaleInitContainer", "image"), tc.Image, err.Error()))
}
}
}
}
}
// We do not validate embedded fields (security context, resource
// requirements etc) as we inherit upstream validation for those fields.
// Invalid values would get rejected by upstream validations at apply
// time.
return violations
}
// maybeCleanup removes tailscale.com finalizer and ensures that the ProxyClass
// is no longer counted towards k8s_proxyclass_resources.
func (pcr *ProxyClassReconciler) maybeCleanup(ctx context.Context, logger *zap.SugaredLogger, pc *tsapi.ProxyClass) error {
ix := slices.Index(pc.Finalizers, FinalizerName)
if ix < 0 {
logger.Debugf("no finalizer, nothing to do")
pcr.mu.Lock()
defer pcr.mu.Unlock()
pcr.managedProxyClasses.Remove(pc.UID)
gaugeProxyClassResources.Set(int64(pcr.managedProxyClasses.Len()))
return nil
}
pc.Finalizers = append(pc.Finalizers[:ix], pc.Finalizers[ix+1:]...)
if err := pcr.Update(ctx, pc); err != nil {
return fmt.Errorf("failed to remove finalizer: %w", err)
}
pcr.mu.Lock()
defer pcr.mu.Unlock()
pcr.managedProxyClasses.Remove(pc.UID)
gaugeProxyClassResources.Set(int64(pcr.managedProxyClasses.Len()))
logger.Infof("ProxyClass resources have been cleaned up")
return nil
}