chore: add custom node taints

This PR adds support for custom node taints. Refer to `nodeTaints` in the `configuration` for more information.

Closes #7581

Signed-off-by: Dmitriy Matrenichev <dmitry.matrenichev@siderolabs.com>

internal/app/machined/pkg/controllers/k8s/node_taint_spec.go

@@ -7,6 +7,7 @@ package k8s
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"github.com/cosi-project/runtime/pkg/controller"
 	"github.com/cosi-project/runtime/pkg/safe"
@@ -53,7 +54,7 @@ func (ctrl *NodeTaintSpecController) Outputs() []controller.Output {
 // Run implements controller.Controller interface.
 //
 //nolint:gocyclo
-func (ctrl *NodeTaintSpecController) Run(ctx context.Context, r controller.Runtime, logger *zap.Logger) error {
+func (ctrl *NodeTaintSpecController) Run(ctx context.Context, r controller.Runtime, _ *zap.Logger) error {
 	for {
 		select {
 		case <-ctx.Done():
@@ -68,16 +69,24 @@ func (ctrl *NodeTaintSpecController) Run(ctx context.Context, r controller.Runti
 
 		r.StartTrackingOutputs()
 
-		if cfg != nil && cfg.Config().Machine() != nil && cfg.Config().Cluster() != nil {
-			if cfg.Config().Machine().Type().IsControlPlane() && !cfg.Config().Cluster().ScheduleOnControlPlanes() {
-				if err = safe.WriterModify(ctx, r, k8s.NewNodeTaintSpec(constants.LabelNodeRoleControlPlane), func(k *k8s.NodeTaintSpec) error {
-					k.TypedSpec().Key = constants.LabelNodeRoleControlPlane
-					k.TypedSpec().Value = ""
-					k.TypedSpec().Effect = string(v1.TaintEffectNoSchedule)
+		if cfg != nil && cfg.Config().Machine() != nil {
+			if cfg.Config().Cluster() != nil {
+				if cfg.Config().Machine().Type().IsControlPlane() && !cfg.Config().Cluster().ScheduleOnControlPlanes() {
+					if err = createTaint(ctx, r, constants.LabelNodeRoleControlPlane, "", string(v1.TaintEffectNoSchedule)); err != nil {
+						return err
+					}
+				}
+			}
 
-					return nil
-				}); err != nil {
-					return fmt.Errorf("error updating node taint spec: %w", err)
+			for key, val := range cfg.Config().Machine().NodeTaints() {
+				value, effect, found := strings.Cut(val, ":")
+				if !found {
+					effect = value
+					value = ""
+				}
+
+				if err = createTaint(ctx, r, key, value, effect); err != nil {
+					return err
 				}
 			}
 		}
@@ -87,3 +96,17 @@ func (ctrl *NodeTaintSpecController) Run(ctx context.Context, r controller.Runti
 		}
 	}
 }
+
+func createTaint(ctx context.Context, r controller.Runtime, key string, val string, effect string) error {
+	if err := safe.WriterModify(ctx, r, k8s.NewNodeTaintSpec(key), func(k *k8s.NodeTaintSpec) error {
+		k.TypedSpec().Key = key
+		k.TypedSpec().Value = val
+		k.TypedSpec().Effect = effect
+
+		return nil
+	}); err != nil {
+		return fmt.Errorf("error updating node taint spec: %w", err)
+	}
+
+	return nil
+}

internal/app/machined/pkg/controllers/k8s/node_taint_spec_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/cosi-project/runtime/pkg/resource/rtestutils"
 	"github.com/cosi-project/runtime/pkg/safe"
 	"github.com/cosi-project/runtime/pkg/state"
+	"github.com/siderolabs/gen/xslices"
 	"github.com/siderolabs/go-pointer"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/suite"
@@ -43,16 +44,19 @@ func TestNodeTaintsSuite(t *testing.T) {
 	})
 }
 
-func (suite *NodeTaintsSuite) updateMachineConfig(machineType machine.Type, allowScheduling bool) {
+func (suite *NodeTaintsSuite) updateMachineConfig(machineType machine.Type, allowScheduling bool, taints ...customTaint) {
 	cfg, err := safe.StateGetByID[*config.MachineConfig](suite.Ctx(), suite.State(), config.V1Alpha1ID)
 	if err != nil && !state.IsNotFoundError(err) {
 		suite.Require().NoError(err)
 	}
 
+	nodeTaints := xslices.ToMap(taints, func(t customTaint) (string, string) { return t.key, t.value })
+
 	if cfg == nil {
 		cfg = config.NewMachineConfig(container.NewV1Alpha1(&v1alpha1.Config{
 			MachineConfig: &v1alpha1.MachineConfig{
-				MachineType: machineType.String(),
+				MachineType:       machineType.String(),
+				MachineNodeTaints: nodeTaints,
 			},
 			ClusterConfig: &v1alpha1.ClusterConfig{
 				AllowSchedulingOnControlPlanes: pointer.To(allowScheduling),
@@ -63,6 +67,7 @@ func (suite *NodeTaintsSuite) updateMachineConfig(machineType machine.Type, allo
 	} else {
 		cfg.Container().RawV1Alpha1().ClusterConfig.AllowSchedulingOnControlPlanes = pointer.To(allowScheduling)
 		cfg.Container().RawV1Alpha1().MachineConfig.MachineType = machineType.String()
+		cfg.Container().RawV1Alpha1().MachineConfig.MachineNodeTaints = nodeTaints
 		suite.Require().NoError(suite.State().Update(suite.Ctx(), cfg))
 	}
 }
@@ -86,3 +91,28 @@ func (suite *NodeTaintsSuite) TestControlplane() {
 
 	rtestutils.AssertNoResource[*k8s.NodeTaintSpec](suite.Ctx(), suite.T(), suite.State(), constants.LabelNodeRoleControlPlane)
 }
+
+func (suite *NodeTaintsSuite) TestCustomTaints() {
+	const customTaintKey = "key1"
+
+	suite.updateMachineConfig(machine.TypeControlPlane, false, customTaint{
+		key:   customTaintKey,
+		value: "value1:NoSchedule",
+	})
+
+	rtestutils.AssertResources(suite.Ctx(), suite.T(), suite.State(), []string{customTaintKey},
+		func(labelSpec *k8s.NodeTaintSpec, asrt *assert.Assertions) {
+			asrt.Equal(customTaintKey, labelSpec.TypedSpec().Key)
+			asrt.Equal("value1", labelSpec.TypedSpec().Value)
+			asrt.Equal(string(v1.TaintEffectNoSchedule), labelSpec.TypedSpec().Effect)
+		})
+
+	suite.updateMachineConfig(machine.TypeControlPlane, false)
+
+	rtestutils.AssertNoResource[*k8s.NodeTaintSpec](suite.Ctx(), suite.T(), suite.State(), customTaintKey)
+}
+
+type customTaint struct {
+	key   string
+	value string
+}

internal/app/machined/pkg/runtime/v1alpha1/v1alpha1_runtime.go

@@ -147,6 +147,7 @@ func (r *Runtime) CanApplyImmediate(cfg config.Provider) error {
 		newConfig.MachineConfig.MachinePods = currentConfig.MachineConfig.MachinePods
 		newConfig.MachineConfig.MachineSeccompProfiles = currentConfig.MachineConfig.MachineSeccompProfiles
 		newConfig.MachineConfig.MachineNodeLabels = currentConfig.MachineConfig.MachineNodeLabels
+		newConfig.MachineConfig.MachineNodeTaints = currentConfig.MachineConfig.MachineNodeTaints
 
 		if newConfig.MachineConfig.MachineFeatures != nil {
 			if currentConfig.MachineConfig.MachineFeatures != nil {

internal/integration/api/node-labels.go

@@ -63,6 +63,8 @@ func (suite *NodeLabelsSuite) TestUpdateWorker() {
 	suite.testUpdate(node, false)
 }
 
+const metadataKeyName = "metadata.name="
+
 // testUpdate cycles through a set of node label updates reverting the change in the end.
 func (suite *NodeLabelsSuite) testUpdate(node string, isControlplane bool) {
 	k8sNode, err := suite.GetK8sNodeByInternalIP(suite.ctx, node)
@@ -71,7 +73,7 @@ func (suite *NodeLabelsSuite) testUpdate(node string, isControlplane bool) {
 	suite.T().Logf("updating labels on node %q (%q)", node, k8sNode.Name)
 
 	watcher, err := suite.Clientset.CoreV1().Nodes().Watch(suite.ctx, metav1.ListOptions{
-		FieldSelector: "metadata.name=" + k8sNode.Name,
+		FieldSelector: metadataKeyName + k8sNode.Name,
 		Watch:         true,
 	})
 	suite.Require().NoError(err)
@@ -135,7 +137,7 @@ func (suite *NodeLabelsSuite) TestAllowScheduling() {
 	suite.T().Logf("updating taints on node %q (%q)", node, k8sNode.Name)
 
 	watcher, err := suite.Clientset.CoreV1().Nodes().Watch(suite.ctx, metav1.ListOptions{
-		FieldSelector: "metadata.name=" + k8sNode.Name,
+		FieldSelector: metadataKeyName + k8sNode.Name,
 		Watch:         true,
 	})
 	suite.Require().NoError(err)
@@ -160,9 +162,9 @@ outer:
 		select {
 		case ev := <-watcher.ResultChan():
 			k8sNode, ok := ev.Object.(*v1.Node)
-			suite.Require().True(ok, "watch event is not of type v1.Node")
+			suite.Require().Truef(ok, "watch event is not of type v1.Node but was %T", ev.Object)
 
-			suite.T().Logf("labels %v, taints %v", k8sNode.Labels, k8sNode.Spec.Taints)
+			suite.T().Logf("labels %#v, taints %#v", k8sNode.Labels, k8sNode.Spec.Taints)
 
 			for k, v := range expectedLabels {
 				if v == "" {
@@ -175,7 +177,7 @@ outer:
 				}
 
 				if k8sNode.Labels[k] != v {
-					suite.T().Logf("label %q is not %q", k, v)
+					suite.T().Logf("label %q is %q but expected %q", k, k8sNode.Labels[k], v)
 
 					continue outer
 				}

internal/integration/api/node-taints.go

@@ -0,0 +1,189 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+//go:build integration_api
+
+package api
+
+import (
+	"context"
+	"slices"
+	"strings"
+	"time"
+
+	"github.com/siderolabs/gen/maps"
+	"github.com/siderolabs/gen/xslices"
+	"github.com/siderolabs/gen/xtesting/must"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/watch"
+
+	"github.com/siderolabs/talos/internal/integration/base"
+	machineapi "github.com/siderolabs/talos/pkg/machinery/api/machine"
+	"github.com/siderolabs/talos/pkg/machinery/client"
+	"github.com/siderolabs/talos/pkg/machinery/config/container"
+	"github.com/siderolabs/talos/pkg/machinery/config/machine"
+	"github.com/siderolabs/talos/pkg/machinery/constants"
+)
+
+// NodeTaintsSuite verifies updating node taints via machine config.
+type NodeTaintsSuite struct {
+	base.K8sSuite
+
+	ctx       context.Context //nolint:containedctx
+	ctxCancel context.CancelFunc
+}
+
+// SuiteName ...
+func (suite *NodeTaintsSuite) SuiteName() string {
+	return "api.NodeTaintsSuite"
+}
+
+// SetupTest ...
+func (suite *NodeTaintsSuite) SetupTest() {
+	// make sure API calls have timeout
+	suite.ctx, suite.ctxCancel = context.WithTimeout(context.Background(), 5*time.Minute)
+}
+
+// TearDownTest ...
+func (suite *NodeTaintsSuite) TearDownTest() {
+	if suite.ctxCancel != nil {
+		suite.ctxCancel()
+	}
+}
+
+// TestUpdateControlPlane verifies node taints updates on control plane nodes.
+func (suite *NodeTaintsSuite) TestUpdateControlPlane() {
+	node := suite.RandomDiscoveredNodeInternalIP(machine.TypeControlPlane)
+
+	suite.testUpdate(node)
+}
+
+// testUpdate cycles through a set of node taints updates reverting the change in the end.
+func (suite *NodeTaintsSuite) testUpdate(node string) {
+	k8sNode, err := suite.GetK8sNodeByInternalIP(suite.ctx, node)
+	suite.Require().NoError(err)
+
+	suite.T().Logf("updating taints on node %q (%q)", node, k8sNode.Name)
+
+	watcher, err := suite.Clientset.CoreV1().Nodes().Watch(suite.ctx, metav1.ListOptions{
+		FieldSelector: metadataKeyName + k8sNode.Name,
+		Watch:         true,
+	})
+	suite.Require().NoError(err)
+
+	defer watcher.Stop()
+
+	// set two new taints
+	suite.setNodeTaints(node, map[string]string{
+		"talos.dev/test1": "value1:NoSchedule",
+		"talos.dev/test2": "NoSchedule",
+	})
+
+	suite.waitUntil(watcher, map[string]string{
+		constants.LabelNodeRoleControlPlane: "NoSchedule",
+		"talos.dev/test1":                   "value1:NoSchedule",
+		"talos.dev/test2":                   "NoSchedule",
+	})
+
+	// remove one taint
+	suite.setNodeTaints(node, map[string]string{
+		"talos.dev/test1": "value1:NoSchedule",
+	})
+
+	suite.waitUntil(watcher, map[string]string{
+		constants.LabelNodeRoleControlPlane: "NoSchedule",
+		"talos.dev/test1":                   "value1:NoSchedule",
+	})
+
+	// remove all taints
+	suite.setNodeTaints(node, nil)
+
+	suite.waitUntil(watcher, map[string]string{
+		constants.LabelNodeRoleControlPlane: "NoSchedule",
+	})
+}
+
+func (suite *NodeTaintsSuite) waitUntil(watcher watch.Interface, expectedTaints map[string]string) {
+outer:
+	for {
+		select {
+		case ev := <-watcher.ResultChan():
+			k8sNode, ok := ev.Object.(*v1.Node)
+			suite.Require().Truef(ok, "watch event is not of type v1.Node but was %T", ev.Object)
+
+			suite.T().Logf("labels %#v, taints %#v", k8sNode.Labels, k8sNode.Spec.Taints)
+
+			taints := xslices.ToMap(k8sNode.Spec.Taints, func(t v1.Taint) (string, string) {
+				switch {
+				case t.Value == "":
+					return t.Key, string(t.Effect)
+				case t.Effect == "":
+					return t.Key, t.Value
+				default:
+					return t.Key, strings.Join([]string{t.Value, string(t.Effect)}, ":")
+				}
+			})
+
+			expectedTaintsKeys := maps.Keys(expectedTaints)
+
+			slices.Sort(expectedTaintsKeys)
+
+			for _, key := range expectedTaintsKeys {
+				actualValue, ok := taints[key]
+				if !ok {
+					suite.T().Logf("taint %q is not present", key)
+
+					continue outer
+				}
+
+				expectedValue := expectedTaints[key]
+
+				if expectedValue != actualValue {
+					suite.T().Logf("expected taint %q to be %q but was %q", key, expectedValue, actualValue)
+
+					continue outer
+				}
+
+				delete(taints, key)
+			}
+
+			if len(taints) > 0 {
+				keys := maps.Keys(taints)
+
+				slices.Sort(keys)
+
+				suite.T().Logf("taints %v are still present", keys)
+
+				continue outer
+			}
+
+			return
+		case <-suite.ctx.Done():
+			suite.T().Fatal("timeout")
+		}
+	}
+}
+
+func (suite *NodeTaintsSuite) setNodeTaints(nodeIP string, nodeTaints map[string]string) {
+	nodeCtx := client.WithNode(suite.ctx, nodeIP)
+
+	nodeConfig := must.Value(suite.ReadConfigFromNode(nodeCtx))(suite.T())
+
+	nodeConfigRaw := nodeConfig.RawV1Alpha1()
+	suite.Require().NotNil(nodeConfigRaw, "node config is not of type v1alpha1.Config")
+
+	nodeConfigRaw.MachineConfig.MachineNodeTaints = nodeTaints
+
+	bytes := must.Value(container.NewV1Alpha1(nodeConfigRaw).Bytes())(suite.T())
+
+	must.Value(suite.Client.ApplyConfiguration(nodeCtx, &machineapi.ApplyConfigurationRequest{
+		Data: bytes,
+		Mode: machineapi.ApplyConfigurationRequest_NO_REBOOT,
+	}))(suite.T())
+}
+
+func init() {
+	allSuites = append(allSuites, new(NodeTaintsSuite))
+}

pkg/machinery/config/config/machine.go

@@ -42,6 +42,7 @@ type MachineConfig interface {
 	Kernel() Kernel
 	SeccompProfiles() []SeccompProfile
 	NodeLabels() NodeLabels
+	NodeTaints() NodeTaints
 }
 
 // SeccompProfile defines the requirements for a config that pertains to seccomp
@@ -54,6 +55,9 @@ type SeccompProfile interface {
 // NodeLabels defines the labels that should be set on a node.
 type NodeLabels map[string]string
 
+// NodeTaints defines the taints that should be set on a node.
+type NodeTaints map[string]string
+
 // Disk represents the options available for partitioning, formatting, and
 // mounting extra disks.
 type Disk interface {

pkg/machinery/config/container/container_test.go

@@ -8,6 +8,7 @@ import (
 	"net/url"
 	"testing"
 
+	"github.com/siderolabs/gen/xtesting/must"
 	"github.com/siderolabs/go-pointer"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -34,7 +35,7 @@ func TestNew(t *testing.T) {
 	}
 
 	sideroLinkCfg := siderolink.NewConfigV1Alpha1()
-	sideroLinkCfg.APIUrlConfig.URL = must(url.Parse("https://siderolink.api/join?jointoken=secret&user=alice"))
+	sideroLinkCfg.APIUrlConfig.URL = must.Value(url.Parse("https://siderolink.api/join?jointoken=secret&user=alice"))(t)
 
 	cfg, err := container.New(v1alpha1Cfg, sideroLinkCfg)
 	require.NoError(t, err)
@@ -81,7 +82,7 @@ func TestValidate(t *testing.T) {
 	t.Parallel()
 
 	sideroLinkCfg := siderolink.NewConfigV1Alpha1()
-	sideroLinkCfg.APIUrlConfig.URL = must(url.Parse("https://siderolink.api/?jointoken=secret&user=alice"))
+	sideroLinkCfg.APIUrlConfig.URL = must.Value(url.Parse("https://siderolink.api/?jointoken=secret&user=alice"))(t)
 
 	invalidSideroLinkCfg := siderolink.NewConfigV1Alpha1()
 
@@ -89,7 +90,7 @@ func TestValidate(t *testing.T) {
 		ClusterConfig: &v1alpha1.ClusterConfig{
 			ControlPlane: &v1alpha1.ControlPlaneConfig{
 				Endpoint: &v1alpha1.Endpoint{
-					URL: must(url.Parse("https://localhost:6443")),
+					URL: must.Value(url.Parse("https://localhost:6443"))(t),
 				},
 			},
 		},
@@ -159,14 +160,6 @@ func TestValidate(t *testing.T) {
 	}
 }
 
-func must[T any](t T, err error) T {
-	if err != nil {
-		panic(err)
-	}
-
-	return t
-}
-
 type validationMode struct{}
 
 func (validationMode) String() string {

pkg/machinery/config/types/v1alpha1/schemas/v1alpha1_config.schema.json

@@ -2096,6 +2096,18 @@
           "description": "Configures the node labels for the machine.\n",
           "markdownDescription": "Configures the node labels for the machine.",
           "x-intellij-html-description": "\u003cp\u003eConfigures the node labels for the machine.\u003c/p\u003e\n"
+        },
+        "nodeTaints": {
+          "patternProperties": {
+            ".*": {
+              "type": "string"
+            }
+          },
+          "type": "object",
+          "title": "nodeTaints",
+          "description": "Configures the node taints for the machine. Effect is optional.\n",
+          "markdownDescription": "Configures the node taints for the machine. Effect is optional.",
+          "x-intellij-html-description": "\u003cp\u003eConfigures the node taints for the machine. Effect is optional.\u003c/p\u003e\n"
         }
       },
       "additionalProperties": false,

pkg/machinery/config/types/v1alpha1/v1alpha1_provider.go

@@ -90,6 +90,11 @@ func (m *MachineConfig) NodeLabels() config.NodeLabels {
 	return m.MachineNodeLabels
 }
 
+// NodeTaints implements the config.Provider interface.
+func (m *MachineConfig) NodeTaints() config.NodeTaints {
+	return m.MachineNodeTaints
+}
+
 // Cluster implements the config.Provider interface.
 func (c *Config) Cluster() config.ClusterConfig {
 	if c == nil || c.ClusterConfig == nil {

pkg/machinery/config/types/v1alpha1/v1alpha1_types.go

@@ -281,6 +281,12 @@ type MachineConfig struct {
 	//    - name: node labels example.
 	//      value: 'map[string]string{"exampleLabel": "exampleLabelValue"}'
 	MachineNodeLabels map[string]string `yaml:"nodeLabels,omitempty"`
+	//  description: |
+	//    Configures the node taints for the machine. Effect is optional.
+	//  examples:
+	//    - name: node taints example.
+	//      value: 'map[string]string{"exampleTaint": "exampleTaintValue:NoSchedule"}'
+	MachineNodeTaints map[string]string `yaml:"nodeTaints,omitempty"`
 }
 
 // MachineSeccompProfile defines seccomp profiles for the machine.

pkg/machinery/config/types/v1alpha1/v1alpha1_types_doc.go

@@ -255,6 +255,13 @@ func (MachineConfig) Doc() *encoder.Doc {
 				Description: "Configures the node labels for the machine.",
 				Comments:    [3]string{"" /* encoder.HeadComment */, "Configures the node labels for the machine." /* encoder.LineComment */, "" /* encoder.FootComment */},
 			},
+			{
+				Name:        "nodeTaints",
+				Type:        "map[string]string",
+				Note:        "",
+				Description: "Configures the node taints for the machine. Effect is optional.",
+				Comments:    [3]string{"" /* encoder.HeadComment */, "Configures the node taints for the machine. Effect is optional." /* encoder.LineComment */, "" /* encoder.FootComment */},
+			},
 		},
 	}
 
@@ -284,6 +291,7 @@ func (MachineConfig) Doc() *encoder.Doc {
 	doc.Fields[20].AddExample("", machineKernelExample())
 	doc.Fields[21].AddExample("", machineSeccompExample())
 	doc.Fields[22].AddExample("node labels example.", map[string]string{"exampleLabel": "exampleLabelValue"})
+	doc.Fields[23].AddExample("node taints example.", map[string]string{"exampleTaint": "exampleTaintValue:NoSchedule"})
 
 	return doc
 }

pkg/machinery/config/types/v1alpha1/v1alpha1_validation.go

@@ -286,6 +286,10 @@ func (c *Config) Validate(mode validation.RuntimeMode, options ...validation.Opt
 		result = multierror.Append(result, fmt.Errorf("invalid machine node labels: %w", err))
 	}
 
+	if err := labels.ValidateTaints(c.MachineConfig.MachineNodeTaints); err != nil {
+		result = multierror.Append(result, fmt.Errorf("invalid machine node taints: %w", err))
+	}
+
 	if c.Machine().Features().KubernetesTalosAPIAccess().Enabled() {
 		if !c.Machine().Features().RBACEnabled() {
 			result = multierror.Append(result, fmt.Errorf("feature API RBAC should be enabled when Kubernetes Talos API Access feature is enabled"))

pkg/machinery/config/types/v1alpha1/zz_generated.deepcopy.go

@@ -1600,6 +1600,13 @@ func (in *MachineConfig) DeepCopyInto(out *MachineConfig) {
 			(*out)[key] = val
 		}
 	}
+	if in.MachineNodeTaints != nil {
+		in, out := &in.MachineNodeTaints, &out.MachineNodeTaints
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 

pkg/machinery/constants/constants.go

@@ -1005,6 +1005,13 @@ var UdevdDroppedCapabilities = map[string]struct{}{
 	"cap_sys_boot": {},
 }
 
+// ValidEffects is the set of valid taint effects.
+var ValidEffects = []string{
+	"NoSchedule",
+	"PreferNoSchedule",
+	"NoExecute",
+}
+
 // OSReleaseTemplate is the template for /etc/os-release.
 const OSReleaseTemplate = `NAME="{{ .Name }}"
 ID={{ .ID }}

pkg/machinery/labels/validate.go

@@ -10,11 +10,13 @@ package labels
 import (
 	"fmt"
 	"regexp"
-	"sort"
+	"slices"
 	"strings"
 
 	"github.com/hashicorp/go-multierror"
 	"github.com/siderolabs/gen/maps"
+
+	"github.com/siderolabs/talos/pkg/machinery/constants"
 )
 
 // Validate validates that a set of labels are correctly defined.
@@ -22,7 +24,7 @@ func Validate(labels map[string]string) error {
 	var multiErr *multierror.Error
 
 	keys := maps.Keys(labels)
-	sort.Strings(keys)
+	slices.Sort(keys)
 
 	for _, k := range keys {
 		if err := ValidateQualifiedName(k); err != nil {
@@ -130,3 +132,41 @@ func ValidateLabelValue(value string) error {
 
 	return nil
 }
+
+// ValidateTaints validates that a set of taints is correctly defined.
+func ValidateTaints(taints map[string]string) error {
+	var multiErr *multierror.Error
+
+	keys := maps.Keys(taints)
+	slices.Sort(keys)
+
+	for _, k := range keys {
+		if err := ValidateQualifiedName(k); err != nil {
+			multiErr = multierror.Append(multiErr, err)
+
+			continue
+		}
+
+		val, effect, found := strings.Cut(taints[k], ":")
+		if !found {
+			effect = val
+		}
+
+		// validate that the taint has a valid effect, which is required to add the taint
+		if !slices.Contains(constants.ValidEffects, effect) {
+			multiErr = multierror.Append(multiErr, fmt.Errorf("invalid taint effect: %q", effect))
+
+			continue
+		}
+
+		if found {
+			if err := ValidateLabelValue(val); err != nil {
+				multiErr = multierror.Append(multiErr, err)
+
+				continue
+			}
+		}
+	}
+
+	return multiErr.ErrorOrNil()
+}

pkg/machinery/labels/validate_test.go

@@ -55,3 +55,44 @@ func TestValidate(t *testing.T) {
 		})
 	}
 }
+
+func TestValidateTaints(t *testing.T) {
+	for _, tt := range []struct {
+		name   string
+		taints map[string]string
+
+		expectedError string
+	}{
+		{
+			name: "empty",
+		},
+		{
+			name: "valid",
+			taints: map[string]string{
+				"foor": "bar:NoExecute",
+				"doo":  "NoExecute",
+			},
+		},
+		{
+			name: "invalid",
+			taints: map[string]string{
+				strings.Repeat("a", 64): "bar",
+				"bar":                   strings.Repeat("a", 64),
+				"foo":                   "bar:NoExecute:NoSchedule",
+				"loo":                   "bar:",
+				"zoo":                   "bar:NoExocute",
+				"koo":                   "key",
+			},
+			expectedError: "6 errors occurred:\n\t* name is too long: \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\" (limit is 63)\n\t* invalid taint effect: \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\"\n\t* invalid taint effect: \"NoExecute:NoSchedule\"\n\t* invalid taint effect: \"key\"\n\t* invalid taint effect: \"\"\n\t* invalid taint effect: \"NoExocute\"\n\n", //nolint:lll
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			err := labels.ValidateTaints(tt.taints)
+			if tt.expectedError != "" {
+				assert.EqualError(t, err, tt.expectedError)
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}

website/content/v1.6/reference/configuration.md

@@ -433,6 +433,10 @@ seccompProfiles:
 nodeLabels:
     exampleLabel: exampleLabelValue
 {{< /highlight >}}</details> | |
+|`nodeTaints` |map[string]string |Configures the node taints for the machine. Effect is optional. <details><summary>Show example(s)</summary>{{< highlight yaml >}}
+nodeTaints:
+    exampleTaint: exampleTaintValue:NoSchedule
+{{< /highlight >}}</details> | |
 
 
 

website/content/v1.6/schemas/v1alpha1_config.schema.json

@@ -2096,6 +2096,18 @@
           "description": "Configures the node labels for the machine.\n",
           "markdownDescription": "Configures the node labels for the machine.",
           "x-intellij-html-description": "\u003cp\u003eConfigures the node labels for the machine.\u003c/p\u003e\n"
+        },
+        "nodeTaints": {
+          "patternProperties": {
+            ".*": {
+              "type": "string"
+            }
+          },
+          "type": "object",
+          "title": "nodeTaints",
+          "description": "Configures the node taints for the machine. Effect is optional.\n",
+          "markdownDescription": "Configures the node taints for the machine. Effect is optional.",
+          "x-intellij-html-description": "\u003cp\u003eConfigures the node taints for the machine. Effect is optional.\u003c/p\u003e\n"
         }
       },
       "additionalProperties": false,