Add support for self-signed CA certificates (#2268)

Co-authored-by: Bassem Dghaidi <568794+Link-@users.noreply.github.com>
Co-authored-by: Nikola Jokic <jokicnikola07@gmail.com>
Co-authored-by: Tingluo Huang <tingluohuang@github.com>

controllers/actions.github.com/autoscalinglistener_controller.go

@@ -423,6 +423,15 @@ func (r *AutoscalingListenerReconciler) createListenerPod(ctx context.Context, a
 		}
 	}
 
+	if autoscalingListener.Spec.GitHubServerTLS != nil {
+		env, err := r.certificateEnvVarForListener(ctx, autoscalingRunnerSet, autoscalingListener)
+		if err != nil {
+			return ctrl.Result{}, fmt.Errorf("failed to create certificate env var for listener: %v", err)
+		}
+
+		envs = append(envs, env)
+	}
+
 	newPod := r.resourceBuilder.newScaleSetListenerPod(autoscalingListener, serviceAccount, secret, envs...)
 
 	if err := ctrl.SetControllerReference(autoscalingListener, newPod, r.Scheme); err != nil {
@@ -439,6 +448,47 @@ func (r *AutoscalingListenerReconciler) createListenerPod(ctx context.Context, a
 	return ctrl.Result{}, nil
 }
 
+func (r *AutoscalingListenerReconciler) certificateEnvVarForListener(ctx context.Context, autoscalingRunnerSet *v1alpha1.AutoscalingRunnerSet, autoscalingListener *v1alpha1.AutoscalingListener) (corev1.EnvVar, error) {
+	if autoscalingListener.Spec.GitHubServerTLS.CertificateFrom == nil {
+		return corev1.EnvVar{}, fmt.Errorf("githubServerTLS.certificateFrom is not specified")
+	}
+
+	if autoscalingListener.Spec.GitHubServerTLS.CertificateFrom.ConfigMapKeyRef == nil {
+		return corev1.EnvVar{}, fmt.Errorf("githubServerTLS.certificateFrom.configMapKeyRef is not specified")
+	}
+
+	var configmap corev1.ConfigMap
+	err := r.Get(
+		ctx,
+		types.NamespacedName{
+			Namespace: autoscalingRunnerSet.Namespace,
+			Name:      autoscalingListener.Spec.GitHubServerTLS.CertificateFrom.ConfigMapKeyRef.Name,
+		},
+		&configmap,
+	)
+	if err != nil {
+		return corev1.EnvVar{}, fmt.Errorf(
+			"failed to get configmap %s: %w",
+			autoscalingListener.Spec.GitHubServerTLS.CertificateFrom.ConfigMapKeyRef.Name,
+			err,
+		)
+	}
+
+	certificate, ok := configmap.Data[autoscalingListener.Spec.GitHubServerTLS.CertificateFrom.ConfigMapKeyRef.Key]
+	if !ok {
+		return corev1.EnvVar{}, fmt.Errorf(
+			"key %s is not found in configmap %s",
+			autoscalingListener.Spec.GitHubServerTLS.CertificateFrom.ConfigMapKeyRef.Key,
+			autoscalingListener.Spec.GitHubServerTLS.CertificateFrom.ConfigMapKeyRef.Name,
+		)
+	}
+
+	return corev1.EnvVar{
+		Name:  "GITHUB_SERVER_ROOT_CA",
+		Value: certificate,
+	}, nil
+}
+
 func (r *AutoscalingListenerReconciler) createSecretsForListener(ctx context.Context, autoscalingListener *v1alpha1.AutoscalingListener, secret *corev1.Secret, logger logr.Logger) (ctrl.Result, error) {
 	newListenerSecret := r.resourceBuilder.newScaleSetListenerSecretMirror(autoscalingListener, secret)
 

controllers/actions.github.com/autoscalinglistener_controller_test.go

@@ -3,6 +3,8 @@ package actionsgithubcom
 import (
 	"context"
 	"fmt"
+	"os"
+	"path/filepath"
 	"time"
 
 	corev1 "k8s.io/api/core/v1"
@@ -554,3 +556,165 @@ var _ = Describe("Test AutoScalingListener controller with proxy", func() {
 			autoscalingListenerTestInterval).Should(Succeed(), "failed to delete secret with proxy details")
 	})
 })
+
+var _ = Describe("Test GitHub Server TLS configuration", func() {
+	var ctx context.Context
+	var mgr ctrl.Manager
+	var autoscalingNS *corev1.Namespace
+	var autoscalingRunnerSet *actionsv1alpha1.AutoscalingRunnerSet
+	var configSecret *corev1.Secret
+	var autoscalingListener *actionsv1alpha1.AutoscalingListener
+	var rootCAConfigMap *corev1.ConfigMap
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		autoscalingNS, mgr = createNamespace(GinkgoT(), k8sClient)
+		configSecret = createDefaultSecret(GinkgoT(), k8sClient, autoscalingNS.Name)
+
+		cert, err := os.ReadFile(filepath.Join(
+			"../../",
+			"github",
+			"actions",
+			"testdata",
+			"rootCA.crt",
+		))
+		Expect(err).NotTo(HaveOccurred(), "failed to read root CA cert")
+		rootCAConfigMap = &corev1.ConfigMap{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "root-ca-configmap",
+				Namespace: autoscalingNS.Name,
+			},
+			Data: map[string]string{
+				"rootCA.crt": string(cert),
+			},
+		}
+		err = k8sClient.Create(ctx, rootCAConfigMap)
+		Expect(err).NotTo(HaveOccurred(), "failed to create configmap with root CAs")
+
+		controller := &AutoscalingListenerReconciler{
+			Client: mgr.GetClient(),
+			Scheme: mgr.GetScheme(),
+			Log:    logf.Log,
+		}
+		err = controller.SetupWithManager(mgr)
+		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+
+		min := 1
+		max := 10
+		autoscalingRunnerSet = &actionsv1alpha1.AutoscalingRunnerSet{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test-asrs",
+				Namespace: autoscalingNS.Name,
+			},
+			Spec: actionsv1alpha1.AutoscalingRunnerSetSpec{
+				GitHubConfigUrl:    "https://github.com/owner/repo",
+				GitHubConfigSecret: configSecret.Name,
+				GitHubServerTLS: &actionsv1alpha1.GitHubServerTLSConfig{
+					CertificateFrom: &actionsv1alpha1.TLSCertificateSource{
+						ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+							LocalObjectReference: corev1.LocalObjectReference{
+								Name: rootCAConfigMap.Name,
+							},
+							Key: "rootCA.crt",
+						},
+					},
+				},
+				MaxRunners: &max,
+				MinRunners: &min,
+				Template: corev1.PodTemplateSpec{
+					Spec: corev1.PodSpec{
+						Containers: []corev1.Container{
+							{
+								Name:  "runner",
+								Image: "ghcr.io/actions/runner",
+							},
+						},
+					},
+				},
+			},
+		}
+
+		err = k8sClient.Create(ctx, autoscalingRunnerSet)
+		Expect(err).NotTo(HaveOccurred(), "failed to create AutoScalingRunnerSet")
+
+		autoscalingListener = &actionsv1alpha1.AutoscalingListener{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test-asl",
+				Namespace: autoscalingNS.Name,
+			},
+			Spec: actionsv1alpha1.AutoscalingListenerSpec{
+				GitHubConfigUrl:    "https://github.com/owner/repo",
+				GitHubConfigSecret: configSecret.Name,
+				GitHubServerTLS: &actionsv1alpha1.GitHubServerTLSConfig{
+					CertificateFrom: &actionsv1alpha1.TLSCertificateSource{
+						ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+							LocalObjectReference: corev1.LocalObjectReference{
+								Name: rootCAConfigMap.Name,
+							},
+							Key: "rootCA.crt",
+						},
+					},
+				},
+				RunnerScaleSetId:              1,
+				AutoscalingRunnerSetNamespace: autoscalingRunnerSet.Namespace,
+				AutoscalingRunnerSetName:      autoscalingRunnerSet.Name,
+				EphemeralRunnerSetName:        "test-ers",
+				MaxRunners:                    10,
+				MinRunners:                    1,
+				Image:                         "ghcr.io/owner/repo",
+			},
+		}
+
+		err = k8sClient.Create(ctx, autoscalingListener)
+		Expect(err).NotTo(HaveOccurred(), "failed to create AutoScalingListener")
+
+		startManagers(GinkgoT(), mgr)
+	})
+
+	Context("When creating a new AutoScalingListener", func() {
+		It("It should set the certificates as an environment variable on the pod", func() {
+			pod := new(corev1.Pod)
+			Eventually(
+				func(g Gomega) {
+					err := k8sClient.Get(
+						ctx,
+						client.ObjectKey{
+							Name:      autoscalingListener.Name,
+							Namespace: autoscalingListener.Namespace,
+						},
+						pod,
+					)
+
+					g.Expect(err).NotTo(HaveOccurred(), "failed to get pod")
+					g.Expect(pod.Spec.Containers).NotTo(BeEmpty(), "pod should have containers")
+					g.Expect(pod.Spec.Containers[0].Env).NotTo(BeEmpty(), "pod should have env variables")
+
+					var env *corev1.EnvVar
+					for _, e := range pod.Spec.Containers[0].Env {
+						if e.Name == "GITHUB_SERVER_ROOT_CA" {
+							env = &e
+							break
+						}
+					}
+					g.Expect(env).NotTo(BeNil(), "pod should have an env variable named GITHUB_SERVER_ROOT_CA_PATH")
+
+					cert, err := os.ReadFile(filepath.Join(
+						"../../",
+						"github",
+						"actions",
+						"testdata",
+						"rootCA.crt",
+					))
+					g.Expect(err).NotTo(HaveOccurred(), "failed to read rootCA.crt")
+
+					g.Expect(env.Value).To(
+						BeEquivalentTo(string(cert)),
+						"GITHUB_SERVER_ROOT_CA should be the rootCA.crt",
+					)
+				}).
+				WithTimeout(autoscalingRunnerSetTestTimeout).
+				WithPolling(autoscalingListenerTestInterval).
+				Should(Succeed(), "failed to create pod with volume and env variable")
+		})
+	})
+})

controllers/actions.github.com/autoscalingrunnerset_controller.go

@@ -541,7 +541,23 @@ func (r *AutoscalingRunnerSetReconciler) actionsClientFor(ctx context.Context, a
 		return nil, fmt.Errorf("failed to find GitHub config secret: %w", err)
 	}
 
-	var opts []actions.ClientOption
+	opts, err := r.actionsClientOptionsFor(ctx, autoscalingRunnerSet)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get actions client options: %w", err)
+	}
+
+	return r.ActionsClient.GetClientFromSecret(
+		ctx,
+		autoscalingRunnerSet.Spec.GitHubConfigUrl,
+		autoscalingRunnerSet.Namespace,
+		configSecret.Data,
+		opts...,
+	)
+}
+
+func (r *AutoscalingRunnerSetReconciler) actionsClientOptionsFor(ctx context.Context, autoscalingRunnerSet *v1alpha1.AutoscalingRunnerSet) ([]actions.ClientOption, error) {
+	var options []actions.ClientOption
+
 	if autoscalingRunnerSet.Spec.Proxy != nil {
 		proxyFunc, err := autoscalingRunnerSet.Spec.Proxy.ProxyFunc(func(s string) (*corev1.Secret, error) {
 			var secret corev1.Secret
@@ -556,16 +572,35 @@ func (r *AutoscalingRunnerSetReconciler) actionsClientFor(ctx context.Context, a
 			return nil, fmt.Errorf("failed to get proxy func: %w", err)
 		}
 
-		opts = append(opts, actions.WithProxy(proxyFunc))
+		options = append(options, actions.WithProxy(proxyFunc))
 	}
 
-	return r.ActionsClient.GetClientFromSecret(
-		ctx,
-		autoscalingRunnerSet.Spec.GitHubConfigUrl,
-		autoscalingRunnerSet.Namespace,
-		configSecret.Data,
-		opts...,
-	)
+	tlsConfig := autoscalingRunnerSet.Spec.GitHubServerTLS
+	if tlsConfig != nil {
+		pool, err := tlsConfig.ToCertPool(func(name, key string) ([]byte, error) {
+			var configmap corev1.ConfigMap
+			err := r.Get(
+				ctx,
+				types.NamespacedName{
+					Namespace: autoscalingRunnerSet.Namespace,
+					Name:      name,
+				},
+				&configmap,
+			)
+			if err != nil {
+				return nil, fmt.Errorf("failed to get configmap %s: %w", name, err)
+			}
+
+			return []byte(configmap.Data[key]), nil
+		})
+		if err != nil {
+			return nil, fmt.Errorf("failed to get tls config: %w", err)
+		}
+
+		options = append(options, actions.WithRootCAs(pool))
+	}
+
+	return options, nil
 }
 
 // SetupWithManager sets up the controller with the Manager.

controllers/actions.github.com/autoscalingrunnerset_controller_test.go

@@ -2,10 +2,13 @@ package actionsgithubcom
 
 import (
 	"context"
+	"crypto/tls"
 	"encoding/base64"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -787,4 +790,242 @@ var _ = Describe("Test Client optional configuration", func() {
 			).Should(BeTrue(), "server was not called")
 		})
 	})
+
+	Context("When specifying a configmap for root CAs", func() {
+		var ctx context.Context
+		var mgr ctrl.Manager
+		var autoscalingNS *corev1.Namespace
+		var configSecret *corev1.Secret
+		var rootCAConfigMap *corev1.ConfigMap
+		var controller *AutoscalingRunnerSetReconciler
+
+		BeforeEach(func() {
+			ctx = context.Background()
+			autoscalingNS, mgr = createNamespace(GinkgoT(), k8sClient)
+			configSecret = createDefaultSecret(GinkgoT(), k8sClient, autoscalingNS.Name)
+
+			cert, err := os.ReadFile(filepath.Join(
+				"../../",
+				"github",
+				"actions",
+				"testdata",
+				"rootCA.crt",
+			))
+			Expect(err).NotTo(HaveOccurred(), "failed to read root CA cert")
+			rootCAConfigMap = &corev1.ConfigMap{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "root-ca-configmap",
+					Namespace: autoscalingNS.Name,
+				},
+				Data: map[string]string{
+					"rootCA.crt": string(cert),
+				},
+			}
+			err = k8sClient.Create(ctx, rootCAConfigMap)
+			Expect(err).NotTo(HaveOccurred(), "failed to create configmap with root CAs")
+
+			controller = &AutoscalingRunnerSetReconciler{
+				Client:                             mgr.GetClient(),
+				Scheme:                             mgr.GetScheme(),
+				Log:                                logf.Log,
+				ControllerNamespace:                autoscalingNS.Name,
+				DefaultRunnerScaleSetListenerImage: "ghcr.io/actions/arc",
+				ActionsClient:                      fake.NewMultiClient(),
+			}
+			err = controller.SetupWithManager(mgr)
+			Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+
+			startManagers(GinkgoT(), mgr)
+		})
+
+		It("should be able to make requests to a server using root CAs", func() {
+			controller.ActionsClient = actions.NewMultiClient("test", logr.Discard())
+
+			certsFolder := filepath.Join(
+				"../../",
+				"github",
+				"actions",
+				"testdata",
+			)
+			certPath := filepath.Join(certsFolder, "server.crt")
+			keyPath := filepath.Join(certsFolder, "server.key")
+
+			serverSuccessfullyCalled := false
+			server := testserver.NewUnstarted(GinkgoT(), http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				serverSuccessfullyCalled = true
+				w.WriteHeader(http.StatusOK)
+			}))
+			cert, err := tls.LoadX509KeyPair(certPath, keyPath)
+			Expect(err).NotTo(HaveOccurred(), "failed to load server cert")
+
+			server.TLS = &tls.Config{Certificates: []tls.Certificate{cert}}
+			server.StartTLS()
+
+			min := 1
+			max := 10
+			autoscalingRunnerSet := &v1alpha1.AutoscalingRunnerSet{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "test-asrs",
+					Namespace: autoscalingNS.Name,
+				},
+				Spec: v1alpha1.AutoscalingRunnerSetSpec{
+					GitHubConfigUrl:    server.ConfigURLForOrg("my-org"),
+					GitHubConfigSecret: configSecret.Name,
+					GitHubServerTLS: &v1alpha1.GitHubServerTLSConfig{
+						CertificateFrom: &v1alpha1.TLSCertificateSource{
+							ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+								LocalObjectReference: corev1.LocalObjectReference{
+									Name: rootCAConfigMap.Name,
+								},
+								Key: "rootCA.crt",
+							},
+						},
+					},
+					MaxRunners:  &max,
+					MinRunners:  &min,
+					RunnerGroup: "testgroup",
+					Template: corev1.PodTemplateSpec{
+						Spec: corev1.PodSpec{
+							Containers: []corev1.Container{
+								{
+									Name:  "runner",
+									Image: "ghcr.io/actions/runner",
+								},
+							},
+						},
+					},
+				},
+			}
+
+			err = k8sClient.Create(ctx, autoscalingRunnerSet)
+			Expect(err).NotTo(HaveOccurred(), "failed to create AutoScalingRunnerSet")
+
+			// wait for server to be called
+			Eventually(
+				func() (bool, error) {
+					return serverSuccessfullyCalled, nil
+				},
+				autoscalingRunnerSetTestTimeout,
+				1*time.Nanosecond,
+			).Should(BeTrue(), "server was not called")
+		})
+
+		It("it creates a listener referencing the right configmap for TLS", func() {
+			min := 1
+			max := 10
+			autoscalingRunnerSet := &v1alpha1.AutoscalingRunnerSet{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "test-asrs",
+					Namespace: autoscalingNS.Name,
+				},
+				Spec: v1alpha1.AutoscalingRunnerSetSpec{
+					GitHubConfigUrl:    "https://github.com/owner/repo",
+					GitHubConfigSecret: configSecret.Name,
+					GitHubServerTLS: &v1alpha1.GitHubServerTLSConfig{
+						CertificateFrom: &v1alpha1.TLSCertificateSource{
+							ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+								LocalObjectReference: corev1.LocalObjectReference{
+									Name: rootCAConfigMap.Name,
+								},
+								Key: "rootCA.crt",
+							},
+						},
+					},
+					MaxRunners:  &max,
+					MinRunners:  &min,
+					RunnerGroup: "testgroup",
+					Template: corev1.PodTemplateSpec{
+						Spec: corev1.PodSpec{
+							Containers: []corev1.Container{
+								{
+									Name:  "runner",
+									Image: "ghcr.io/actions/runner",
+								},
+							},
+						},
+					},
+				},
+			}
+
+			err := k8sClient.Create(ctx, autoscalingRunnerSet)
+			Expect(err).NotTo(HaveOccurred(), "failed to create AutoScalingRunnerSet")
+
+			Eventually(
+				func(g Gomega) {
+					listener := new(v1alpha1.AutoscalingListener)
+					err := k8sClient.Get(
+						ctx,
+						client.ObjectKey{
+							Name:      scaleSetListenerName(autoscalingRunnerSet),
+							Namespace: autoscalingRunnerSet.Namespace,
+						},
+						listener,
+					)
+					g.Expect(err).NotTo(HaveOccurred(), "failed to get listener")
+
+					g.Expect(listener.Spec.GitHubServerTLS).NotTo(BeNil(), "listener does not have TLS config")
+					g.Expect(listener.Spec.GitHubServerTLS).To(BeEquivalentTo(autoscalingRunnerSet.Spec.GitHubServerTLS), "listener does not have TLS config")
+				},
+				autoscalingRunnerSetTestTimeout,
+				autoscalingListenerTestInterval,
+			).Should(Succeed(), "tls config is incorrect")
+		})
+
+		It("it creates an ephemeral runner set referencing the right configmap for TLS", func() {
+			min := 1
+			max := 10
+			autoscalingRunnerSet := &v1alpha1.AutoscalingRunnerSet{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "test-asrs",
+					Namespace: autoscalingNS.Name,
+				},
+				Spec: v1alpha1.AutoscalingRunnerSetSpec{
+					GitHubConfigUrl:    "https://github.com/owner/repo",
+					GitHubConfigSecret: configSecret.Name,
+					GitHubServerTLS: &v1alpha1.GitHubServerTLSConfig{
+						CertificateFrom: &v1alpha1.TLSCertificateSource{
+							ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+								LocalObjectReference: corev1.LocalObjectReference{
+									Name: rootCAConfigMap.Name,
+								},
+								Key: "rootCA.crt",
+							},
+						},
+					},
+					MaxRunners:  &max,
+					MinRunners:  &min,
+					RunnerGroup: "testgroup",
+					Template: corev1.PodTemplateSpec{
+						Spec: corev1.PodSpec{
+							Containers: []corev1.Container{
+								{
+									Name:  "runner",
+									Image: "ghcr.io/actions/runner",
+								},
+							},
+						},
+					},
+				},
+			}
+
+			err := k8sClient.Create(ctx, autoscalingRunnerSet)
+			Expect(err).NotTo(HaveOccurred(), "failed to create AutoScalingRunnerSet")
+
+			Eventually(
+				func(g Gomega) {
+					runnerSetList := new(v1alpha1.EphemeralRunnerSetList)
+					err := k8sClient.List(ctx, runnerSetList, client.InNamespace(autoscalingRunnerSet.Namespace))
+					g.Expect(err).NotTo(HaveOccurred(), "failed to list EphemeralRunnerSet")
+					g.Expect(runnerSetList.Items).To(HaveLen(1), "expected 1 EphemeralRunnerSet to be created")
+
+					runnerSet := &runnerSetList.Items[0]
+
+					g.Expect(runnerSet.Spec.EphemeralRunnerSpec.GitHubServerTLS).NotTo(BeNil(), "expected EphemeralRunnerSpec.GitHubServerTLS to be set")
+					g.Expect(runnerSet.Spec.EphemeralRunnerSpec.GitHubServerTLS).To(BeEquivalentTo(autoscalingRunnerSet.Spec.GitHubServerTLS), "EphemeralRunnerSpec does not have TLS config")
+				},
+				autoscalingRunnerSetTestTimeout,
+				autoscalingListenerTestInterval,
+			).Should(Succeed())
+		})
+	})
 })

controllers/actions.github.com/ephemeralrunner_controller.go

@@ -680,6 +680,21 @@ func (r *EphemeralRunnerReconciler) actionsClientFor(ctx context.Context, runner
 		return nil, fmt.Errorf("failed to get secret: %w", err)
 	}
 
+	opts, err := r.actionsClientOptionsFor(ctx, runner)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get actions client options: %w", err)
+	}
+
+	return r.ActionsClient.GetClientFromSecret(
+		ctx,
+		runner.Spec.GitHubConfigUrl,
+		runner.Namespace,
+		secret.Data,
+		opts...,
+	)
+}
+
+func (r *EphemeralRunnerReconciler) actionsClientOptionsFor(ctx context.Context, runner *v1alpha1.EphemeralRunner) ([]actions.ClientOption, error) {
 	var opts []actions.ClientOption
 	if runner.Spec.Proxy != nil {
 		proxyFunc, err := runner.Spec.Proxy.ProxyFunc(func(s string) (*corev1.Secret, error) {
@@ -698,13 +713,32 @@ func (r *EphemeralRunnerReconciler) actionsClientFor(ctx context.Context, runner
 		opts = append(opts, actions.WithProxy(proxyFunc))
 	}
 
-	return r.ActionsClient.GetClientFromSecret(
-		ctx,
-		runner.Spec.GitHubConfigUrl,
-		runner.Namespace,
-		secret.Data,
-		opts...,
-	)
+	tlsConfig := runner.Spec.GitHubServerTLS
+	if tlsConfig != nil {
+		pool, err := tlsConfig.ToCertPool(func(name, key string) ([]byte, error) {
+			var configmap corev1.ConfigMap
+			err := r.Get(
+				ctx,
+				types.NamespacedName{
+					Namespace: runner.Namespace,
+					Name:      name,
+				},
+				&configmap,
+			)
+			if err != nil {
+				return nil, fmt.Errorf("failed to get configmap %s: %w", name, err)
+			}
+
+			return []byte(configmap.Data[key]), nil
+		})
+		if err != nil {
+			return nil, fmt.Errorf("failed to get tls config: %w", err)
+		}
+
+		opts = append(opts, actions.WithRootCAs(pool))
+	}
+
+	return opts, nil
 }
 
 // runnerRegisteredWithService checks if the runner is still registered with the service

controllers/actions.github.com/ephemeralrunner_controller_test.go

@@ -2,10 +2,13 @@ package actionsgithubcom
 
 import (
 	"context"
+	"crypto/tls"
 	"encoding/base64"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -14,6 +17,7 @@ import (
 	"github.com/go-logr/logr"
 
 	"github.com/actions/actions-runner-controller/github/actions/fake"
+	"github.com/actions/actions-runner-controller/github/actions/testserver"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 	corev1 "k8s.io/api/core/v1"
@@ -841,4 +845,100 @@ var _ = Describe("EphemeralRunner", func() {
 			}))
 		})
 	})
+
+	Describe("TLS config", func() {
+		var ctx context.Context
+		var mgr ctrl.Manager
+		var autoScalingNS *corev1.Namespace
+		var configSecret *corev1.Secret
+		var controller *EphemeralRunnerReconciler
+		var rootCAConfigMap *corev1.ConfigMap
+
+		BeforeEach(func() {
+			ctx = context.Background()
+			autoScalingNS, mgr = createNamespace(GinkgoT(), k8sClient)
+			configSecret = createDefaultSecret(GinkgoT(), k8sClient, autoScalingNS.Name)
+
+			cert, err := os.ReadFile(filepath.Join(
+				"../../",
+				"github",
+				"actions",
+				"testdata",
+				"rootCA.crt",
+			))
+			Expect(err).NotTo(HaveOccurred(), "failed to read root CA cert")
+			rootCAConfigMap = &corev1.ConfigMap{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "root-ca-configmap",
+					Namespace: autoScalingNS.Name,
+				},
+				Data: map[string]string{
+					"rootCA.crt": string(cert),
+				},
+			}
+			err = k8sClient.Create(ctx, rootCAConfigMap)
+			Expect(err).NotTo(HaveOccurred(), "failed to create configmap with root CAs")
+
+			controller = &EphemeralRunnerReconciler{
+				Client:        mgr.GetClient(),
+				Scheme:        mgr.GetScheme(),
+				Log:           logf.Log,
+				ActionsClient: fake.NewMultiClient(),
+			}
+
+			err = controller.SetupWithManager(mgr)
+			Expect(err).To(BeNil(), "failed to setup controller")
+
+			startManagers(GinkgoT(), mgr)
+		})
+
+		It("should be able to make requests to a server using root CAs", func() {
+			certsFolder := filepath.Join(
+				"../../",
+				"github",
+				"actions",
+				"testdata",
+			)
+			certPath := filepath.Join(certsFolder, "server.crt")
+			keyPath := filepath.Join(certsFolder, "server.key")
+
+			serverSuccessfullyCalled := false
+			server := testserver.NewUnstarted(GinkgoT(), http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				serverSuccessfullyCalled = true
+				w.WriteHeader(http.StatusOK)
+			}))
+			cert, err := tls.LoadX509KeyPair(certPath, keyPath)
+			Expect(err).NotTo(HaveOccurred(), "failed to load server cert")
+
+			server.TLS = &tls.Config{Certificates: []tls.Certificate{cert}}
+			server.StartTLS()
+
+			// Use an actual client
+			controller.ActionsClient = actions.NewMultiClient("test", logr.Discard())
+
+			ephemeralRunner := newExampleRunner("test-runner", autoScalingNS.Name, configSecret.Name)
+			ephemeralRunner.Spec.GitHubConfigUrl = server.ConfigURLForOrg("my-org")
+			ephemeralRunner.Spec.GitHubServerTLS = &v1alpha1.GitHubServerTLSConfig{
+				CertificateFrom: &v1alpha1.TLSCertificateSource{
+					ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+						LocalObjectReference: corev1.LocalObjectReference{
+							Name: rootCAConfigMap.Name,
+						},
+						Key: "rootCA.crt",
+					},
+				},
+			}
+
+			err = k8sClient.Create(ctx, ephemeralRunner)
+			Expect(err).To(BeNil(), "failed to create ephemeral runner")
+
+			Eventually(
+				func() bool {
+					return serverSuccessfullyCalled
+				},
+				2*time.Second,
+				interval,
+			).Should(BeTrue(), "failed to contact server")
+		})
+	})
 })

controllers/actions.github.com/ephemeralrunnerset_controller.go

@@ -450,6 +450,22 @@ func (r *EphemeralRunnerSetReconciler) actionsClientFor(ctx context.Context, rs
 	if err := r.Get(ctx, types.NamespacedName{Namespace: rs.Namespace, Name: rs.Spec.EphemeralRunnerSpec.GitHubConfigSecret}, secret); err != nil {
 		return nil, fmt.Errorf("failed to get secret: %w", err)
 	}
+
+	opts, err := r.actionsClientOptionsFor(ctx, rs)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get actions client options: %w", err)
+	}
+
+	return r.ActionsClient.GetClientFromSecret(
+		ctx,
+		rs.Spec.EphemeralRunnerSpec.GitHubConfigUrl,
+		rs.Namespace,
+		secret.Data,
+		opts...,
+	)
+}
+
+func (r *EphemeralRunnerSetReconciler) actionsClientOptionsFor(ctx context.Context, rs *v1alpha1.EphemeralRunnerSet) ([]actions.ClientOption, error) {
 	var opts []actions.ClientOption
 	if rs.Spec.EphemeralRunnerSpec.Proxy != nil {
 		proxyFunc, err := rs.Spec.EphemeralRunnerSpec.Proxy.ProxyFunc(func(s string) (*corev1.Secret, error) {
@@ -468,13 +484,32 @@ func (r *EphemeralRunnerSetReconciler) actionsClientFor(ctx context.Context, rs
 		opts = append(opts, actions.WithProxy(proxyFunc))
 	}
 
-	return r.ActionsClient.GetClientFromSecret(
-		ctx,
-		rs.Spec.EphemeralRunnerSpec.GitHubConfigUrl,
-		rs.Namespace,
-		secret.Data,
-		opts...,
-	)
+	tlsConfig := rs.Spec.EphemeralRunnerSpec.GitHubServerTLS
+	if tlsConfig != nil {
+		pool, err := tlsConfig.ToCertPool(func(name, key string) ([]byte, error) {
+			var configmap corev1.ConfigMap
+			err := r.Get(
+				ctx,
+				types.NamespacedName{
+					Namespace: rs.Namespace,
+					Name:      name,
+				},
+				&configmap,
+			)
+			if err != nil {
+				return nil, fmt.Errorf("failed to get configmap %s: %w", name, err)
+			}
+
+			return []byte(configmap.Data[key]), nil
+		})
+		if err != nil {
+			return nil, fmt.Errorf("failed to get tls config: %w", err)
+		}
+
+		opts = append(opts, actions.WithRootCAs(pool))
+	}
+
+	return opts, nil
 }
 
 // SetupWithManager sets up the controller with the Manager.

controllers/actions.github.com/ephemeralrunnerset_controller_test.go

@@ -2,10 +2,13 @@ package actionsgithubcom
 
 import (
 	"context"
+	"crypto/tls"
 	"encoding/base64"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -24,6 +27,7 @@ import (
 	v1alpha1 "github.com/actions/actions-runner-controller/apis/actions.github.com/v1alpha1"
 	"github.com/actions/actions-runner-controller/github/actions"
 	"github.com/actions/actions-runner-controller/github/actions/fake"
+	"github.com/actions/actions-runner-controller/github/actions/testserver"
 )
 
 const (
@@ -834,3 +838,148 @@ var _ = Describe("Test EphemeralRunnerSet controller with proxy settings", func(
 		).Should(BeEquivalentTo(true))
 	})
 })
+
+var _ = Describe("Test EphemeralRunnerSet controller with custom root CA", func() {
+	var ctx context.Context
+	var mgr ctrl.Manager
+	var autoscalingNS *corev1.Namespace
+	var ephemeralRunnerSet *actionsv1alpha1.EphemeralRunnerSet
+	var configSecret *corev1.Secret
+	var rootCAConfigMap *corev1.ConfigMap
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		autoscalingNS, mgr = createNamespace(GinkgoT(), k8sClient)
+		configSecret = createDefaultSecret(GinkgoT(), k8sClient, autoscalingNS.Name)
+
+		cert, err := os.ReadFile(filepath.Join(
+			"../../",
+			"github",
+			"actions",
+			"testdata",
+			"rootCA.crt",
+		))
+		Expect(err).NotTo(HaveOccurred(), "failed to read root CA cert")
+		rootCAConfigMap = &corev1.ConfigMap{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "root-ca-configmap",
+				Namespace: autoscalingNS.Name,
+			},
+			Data: map[string]string{
+				"rootCA.crt": string(cert),
+			},
+		}
+		err = k8sClient.Create(ctx, rootCAConfigMap)
+		Expect(err).NotTo(HaveOccurred(), "failed to create configmap with root CAs")
+
+		controller := &EphemeralRunnerSetReconciler{
+			Client:        mgr.GetClient(),
+			Scheme:        mgr.GetScheme(),
+			Log:           logf.Log,
+			ActionsClient: actions.NewMultiClient("test", logr.Discard()),
+		}
+		err = controller.SetupWithManager(mgr)
+		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+
+		startManagers(GinkgoT(), mgr)
+	})
+
+	It("should be able to make requests to a server using root CAs", func() {
+		certsFolder := filepath.Join(
+			"../../",
+			"github",
+			"actions",
+			"testdata",
+		)
+		certPath := filepath.Join(certsFolder, "server.crt")
+		keyPath := filepath.Join(certsFolder, "server.key")
+
+		serverSuccessfullyCalled := false
+		server := testserver.NewUnstarted(GinkgoT(), http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			serverSuccessfullyCalled = true
+			w.WriteHeader(http.StatusOK)
+		}))
+		cert, err := tls.LoadX509KeyPair(certPath, keyPath)
+		Expect(err).NotTo(HaveOccurred(), "failed to load server cert")
+
+		server.TLS = &tls.Config{Certificates: []tls.Certificate{cert}}
+		server.StartTLS()
+
+		ephemeralRunnerSet = &actionsv1alpha1.EphemeralRunnerSet{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test-asrs",
+				Namespace: autoscalingNS.Name,
+			},
+			Spec: actionsv1alpha1.EphemeralRunnerSetSpec{
+				Replicas: 1,
+				EphemeralRunnerSpec: actionsv1alpha1.EphemeralRunnerSpec{
+					GitHubConfigUrl:    server.ConfigURLForOrg("my-org"),
+					GitHubConfigSecret: configSecret.Name,
+					GitHubServerTLS: &actionsv1alpha1.GitHubServerTLSConfig{
+						CertificateFrom: &v1alpha1.TLSCertificateSource{
+							ConfigMapKeyRef: &corev1.ConfigMapKeySelector{
+								LocalObjectReference: corev1.LocalObjectReference{
+									Name: rootCAConfigMap.Name,
+								},
+								Key: "rootCA.crt",
+							},
+						},
+					},
+					RunnerScaleSetId: 100,
+					PodTemplateSpec: corev1.PodTemplateSpec{
+						Spec: corev1.PodSpec{
+							Containers: []corev1.Container{
+								{
+									Name:  "runner",
+									Image: "ghcr.io/actions/runner",
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+
+		err = k8sClient.Create(ctx, ephemeralRunnerSet)
+		Expect(err).NotTo(HaveOccurred(), "failed to create EphemeralRunnerSet")
+
+		runnerList := new(actionsv1alpha1.EphemeralRunnerList)
+		Eventually(func() (int, error) {
+			err := k8sClient.List(ctx, runnerList, client.InNamespace(ephemeralRunnerSet.Namespace))
+			if err != nil {
+				return -1, err
+			}
+
+			return len(runnerList.Items), nil
+		},
+			ephemeralRunnerSetTestTimeout,
+			ephemeralRunnerSetTestInterval,
+		).Should(BeEquivalentTo(1), "failed to create ephemeral runner")
+
+		runner := runnerList.Items[0].DeepCopy()
+		Expect(runner.Spec.GitHubServerTLS).NotTo(BeNil(), "runner tls config should not be nil")
+		Expect(runner.Spec.GitHubServerTLS).To(BeEquivalentTo(ephemeralRunnerSet.Spec.EphemeralRunnerSpec.GitHubServerTLS), "runner tls config should be correct")
+
+		runner.Status.Phase = corev1.PodRunning
+		runner.Status.RunnerId = 100
+		err = k8sClient.Status().Patch(ctx, runner, client.MergeFrom(&runnerList.Items[0]))
+		Expect(err).NotTo(HaveOccurred(), "failed to update ephemeral runner status")
+
+		updatedRunnerSet := new(actionsv1alpha1.EphemeralRunnerSet)
+		err = k8sClient.Get(ctx, client.ObjectKey{Namespace: ephemeralRunnerSet.Namespace, Name: ephemeralRunnerSet.Name}, updatedRunnerSet)
+		Expect(err).NotTo(HaveOccurred(), "failed to get EphemeralRunnerSet")
+
+		updatedRunnerSet.Spec.Replicas = 0
+		err = k8sClient.Update(ctx, updatedRunnerSet)
+		Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
+
+		// wait for server to be called
+		Eventually(
+			func() bool {
+				return serverSuccessfullyCalled
+			},
+			autoscalingRunnerSetTestTimeout,
+			1*time.Nanosecond,
+		).Should(BeTrue(), "server was not called")
+	})
+})

controllers/actions.github.com/resourcebuilder.go

@@ -307,6 +307,7 @@ func (b *resourceBuilder) newAutoScalingListener(autoscalingRunnerSet *v1alpha1.
 			Image:                         image,
 			ImagePullSecrets:              imagePullSecrets,
 			Proxy:                         autoscalingRunnerSet.Spec.Proxy,
+			GitHubServerTLS:               autoscalingRunnerSet.Spec.GitHubServerTLS,
 		},
 	}
 

controllers/actions.github.com/suite_test.go

@@ -39,9 +39,11 @@ import (
 // These tests use Ginkgo (BDD-style Go testing framework). Refer to
 // http://onsi.github.io/ginkgo/ to learn more about Ginkgo.
 
-var cfg *rest.Config
-var k8sClient client.Client
-var testEnv *envtest.Environment
+var (
+	cfg       *rest.Config
+	k8sClient client.Client
+	testEnv   *envtest.Environment
+)
 
 func TestAPIs(t *testing.T) {
 	RegisterFailHandler(Fail)