diff --git a/cmd/k8s-operator/sts.go b/cmd/k8s-operator/sts.go index d133b8bab..ee344c5dc 100644 --- a/cmd/k8s-operator/sts.go +++ b/cmd/k8s-operator/sts.go @@ -21,6 +21,7 @@ apierrors "k8s.io/apimachinery/pkg/api/errors" metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured" + "k8s.io/apiserver/pkg/storage/names" "sigs.k8s.io/controller-runtime/pkg/client" "sigs.k8s.io/yaml" "tailscale.com/client/tailscale" @@ -176,10 +177,39 @@ func (a *tailscaleSTSReconciler) Cleanup(ctx context.Context, logger *zap.Sugare return true, nil } +// maxStatefulSetNameLength is maximum length the StatefulSet name can +// have to NOT result in a too long value for controller-revision-hash +// label value (see https://github.com/kubernetes/kubernetes/issues/64023). +// controller-revision-hash label value consists of StatefulSet's name + hyphen + revision hash. +// Maximum label value length is 63 chars. Length of revision hash is 10 chars. +// https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set +// https://github.com/kubernetes/kubernetes/blob/v1.28.4/pkg/controller/history/controller_history.go#L90-L104 +const maxStatefulSetNameLength = 63 - 10 - 1 + +// statefulSetNameBase accepts name of parent resource and returns a string in +// form ts-- that, when passed to Kubernetes name +// generation will NOT result in a StatefulSet name longer than 52 chars. +// This is done because of https://github.com/kubernetes/kubernetes/issues/64023. +func statefulSetNameBase(parent string) string { + + base := fmt.Sprintf("ts-%s-", parent) + + // Calculate what length name GenerateName returns for this base. + generator := names.SimpleNameGenerator + generatedName := generator.GenerateName(base) + + if excess := len(generatedName) - maxStatefulSetNameLength; excess > 0 { + base = base[:len(base)-excess-1] // take extra char off to make space for hyphen + base = base + "-" // re-instate hyphen + } + return base +} + func (a *tailscaleSTSReconciler) reconcileHeadlessService(ctx context.Context, logger *zap.SugaredLogger, sts *tailscaleSTSConfig) (*corev1.Service, error) { + nameBase := statefulSetNameBase(sts.ParentResourceName) hsvc := &corev1.Service{ ObjectMeta: metav1.ObjectMeta{ - GenerateName: "ts-" + sts.ParentResourceName + "-", + GenerateName: nameBase, Namespace: a.operatorNamespace, Labels: sts.ChildResourceLabels, }, diff --git a/cmd/k8s-operator/sts_test.go b/cmd/k8s-operator/sts_test.go new file mode 100644 index 000000000..43d57d649 --- /dev/null +++ b/cmd/k8s-operator/sts_test.go @@ -0,0 +1,50 @@ +// Copyright (c) Tailscale Inc & AUTHORS +// SPDX-License-Identifier: BSD-3-Clause + +//go:build !plan9 + +package main + +import ( + "testing" +) + +// Test_statefulSetNameBase tests that parent name portion in a StatefulSet name +// base will be truncated if the parent name is longer than 43 chars to ensure +// that the total does not exceed 52 chars. +// How many chars need to be cut off parent name depends on an internal var in +// kube name generation code that can change at which point this test will break +// and need to be changed. This is okay as we do not rely on that value in +// code whilst being aware when it changes might still be useful. +// https://github.com/kubernetes/kubernetes/blob/v1.28.4/staging/src/k8s.io/apiserver/pkg/storage/names/generate.go#L45. +// https://github.com/kubernetes/kubernetes/pull/116430 +func Test_statefulSetNameBase(t *testing.T) { + tests := []struct { + name string + in string + out string + }{ + { + name: "43 chars", + in: "oidhexl9o832hcbhyg4uz6o0s7u9uae54h5k8ofs9xb", + out: "ts-oidhexl9o832hcbhyg4uz6o0s7u9uae54h5k8ofs9xb-", + }, + { + name: "44 chars", + in: "oidhexl9o832hcbhyg4uz6o0s7u9uae54h5k8ofs9xbo", + out: "ts-oidhexl9o832hcbhyg4uz6o0s7u9uae54h5k8ofs9xb-", + }, + { + name: "42 chars", + in: "oidhexl9o832hcbhyg4uz6o0s7u9uae54h5k8ofs9x", + out: "ts-oidhexl9o832hcbhyg4uz6o0s7u9uae54h5k8ofs9x-", + }, + } + for _, tt := range tests { + t.Run(tt.name, func(t *testing.T) { + if got := statefulSetNameBase(tt.in); got != tt.out { + t.Errorf("stsNamePrefix(%s) = %q, want %s", tt.in, got, tt.out) + } + }) + } +} diff --git a/go.mod b/go.mod index 5ab0ac353..7e636cae8 100644 --- a/go.mod +++ b/go.mod @@ -97,6 +97,7 @@ require ( inet.af/wf v0.0.0-20221017222439-36129f591884 k8s.io/api v0.28.2 k8s.io/apimachinery v0.28.2 + k8s.io/apiserver v0.28.2 k8s.io/client-go v0.28.2 nhooyr.io/websocket v1.8.7 sigs.k8s.io/controller-runtime v0.16.2 diff --git a/go.sum b/go.sum index 0c8f2697c..251a8104d 100644 --- a/go.sum +++ b/go.sum @@ -1449,6 +1449,8 @@ k8s.io/apiextensions-apiserver v0.28.2 h1:J6/QRWIKV2/HwBhHRVITMLYoypCoPY1ftigDM0 k8s.io/apiextensions-apiserver v0.28.2/go.mod h1:5tnkxLGa9nefefYzWuAlWZ7RZYuN/765Au8cWLA6SRg= k8s.io/apimachinery v0.28.2 h1:KCOJLrc6gu+wV1BYgwik4AF4vXOlVJPdiqn0yAWWwXQ= k8s.io/apimachinery v0.28.2/go.mod h1:RdzF87y/ngqk9H4z3EL2Rppv5jj95vGS/HaFXrLDApU= +k8s.io/apiserver v0.28.2 h1:rBeYkLvF94Nku9XfXyUIirsVzCzJBs6jMn3NWeHieyI= +k8s.io/apiserver v0.28.2/go.mod h1:f7D5e8wH8MWcKD7azq6Csw9UN+CjdtXIVQUyUhrtb+E= k8s.io/client-go v0.28.2 h1:DNoYI1vGq0slMBN/SWKMZMw0Rq+0EQW6/AK4v9+3VeY= k8s.io/client-go v0.28.2/go.mod h1:sMkApowspLuc7omj1FOSUxSoqjr+d5Q0Yc0LOFnYFJY= k8s.io/component-base v0.28.2 h1:Yc1yU+6AQSlpJZyvehm/NkJBII72rzlEsd6MkBQ+G0E=