Flexible image pull secret reference (#3016)

Co-authored-by: pat-s <patrick.schratz@gmail.com>

docs/versioned_docs/version-2.1/30-administration/22-backends/40-kubernetes.md

@@ -46,6 +46,10 @@ agent:
 
   Determines if containers must be required to run as non-root users.
 
+- `WOODPECKER_BACKEND_K8S_PULL_SECRET_NAMES` (default: empty)
+
+  Secret names to pull images from private repositories.
+
 ## Job specific configuration
 
 ### Resources

docs/versioned_docs/version-2.1/91-migrations.md

@@ -7,6 +7,7 @@ Some versions need some changes to the server configuration or the pipeline conf
 - Deprecated `steps.[name].group` in favor of `steps.[name].depends_on` (see [workflow syntax](./20-usage/20-workflow-syntax.md#depends_on) to learn how to set dependencies)
 - Removed `WOODPECKER_ROOT_PATH` and `WOODPECKER_ROOT_URL` config variables. Use `WOODPECKER_HOST` with a path instead
 - Pipelines without a config file will now be skipped instead of failing
+- Deprecated implicitly defined `regcred` image pull secret. Set it explicitly via `WOODPECKER_BACKEND_K8S_PULL_SECRET_NAMES`.
 
 ## 2.0.0
 

pipeline/backend/kubernetes/flags.go

@@ -74,4 +74,10 @@ var Flags = []cli.Flag{
 		Usage:   "duration to wait before retrying to connect to the server",
 		Value:   time.Second * 2,
 	},
+	&cli.StringSliceFlag{
+		EnvVars: []string{"WOODPECKER_BACKEND_K8S_PULL_SECRET_NAMES"},
+		Name:    "backend-k8s-pod-image-pull-secret-names",
+		Usage:   "backend k8s pull secret names for private registries",
+		Value:   cli.NewStringSlice("regcred"),
+	},
 }

pipeline/backend/kubernetes/kubernetes.go

@@ -54,13 +54,14 @@ type kube struct {
 }
 
 type config struct {
-	Namespace       string
-	StorageClass    string
-	VolumeSize      string
-	StorageRwx      bool
-	PodLabels       map[string]string
-	PodAnnotations  map[string]string
-	SecurityContext SecurityContextConfig
+	Namespace            string
+	StorageClass         string
+	VolumeSize           string
+	StorageRwx           bool
+	PodLabels            map[string]string
+	PodAnnotations       map[string]string
+	ImagePullSecretNames []string
+	SecurityContext      SecurityContextConfig
 }
 type SecurityContextConfig struct {
 	RunAsNonRoot bool
@@ -80,16 +81,21 @@ func configFromCliContext(ctx context.Context) (*config, error) {
 	if ctx != nil {
 		if c, ok := ctx.Value(types.CliContext).(*cli.Context); ok {
 			config := config{
-				Namespace:      c.String("backend-k8s-namespace"),
-				StorageClass:   c.String("backend-k8s-storage-class"),
-				VolumeSize:     c.String("backend-k8s-volume-size"),
-				StorageRwx:     c.Bool("backend-k8s-storage-rwx"),
-				PodLabels:      make(map[string]string), // just init empty map to prevent nil panic
-				PodAnnotations: make(map[string]string), // just init empty map to prevent nil panic
+				Namespace:            c.String("backend-k8s-namespace"),
+				StorageClass:         c.String("backend-k8s-storage-class"),
+				VolumeSize:           c.String("backend-k8s-volume-size"),
+				StorageRwx:           c.Bool("backend-k8s-storage-rwx"),
+				PodLabels:            make(map[string]string), // just init empty map to prevent nil panic
+				PodAnnotations:       make(map[string]string), // just init empty map to prevent nil panic
+				ImagePullSecretNames: c.StringSlice("backend-k8s-pod-image-pull-secret-names"),
 				SecurityContext: SecurityContextConfig{
 					RunAsNonRoot: c.Bool("backend-k8s-secctx-nonroot"),
 				},
 			}
+			// TODO: remove in next major
+			if len(config.ImagePullSecretNames) == 1 && config.ImagePullSecretNames[0] == "regcred" {
+				log.Warn().Msg("WOODPECKER_BACKEND_K8S_PULL_SECRET_NAMES is set to the default ('regcred'). It will default to empty in Woodpecker 3.0. Set it explicitly before then.")
+			}
 			// Unmarshal label and annotation settings here to ensure they're valid on startup
 			if labels := c.String("backend-k8s-pod-labels"); labels != "" {
 				if err := yaml.Unmarshal([]byte(labels), &config.PodLabels); err != nil {

pipeline/backend/kubernetes/pod.go

@@ -36,7 +36,7 @@ const (
 
 func mkPod(namespace, name, image, workDir, goos, serviceAccountName string,
 	pool, privileged bool,
-	commands, vols []string,
+	commands, vols, pullSecretNames []string,
 	labels, annotations, env, nodeSelector map[string]string,
 	extraHosts []types.HostAlias, tolerations []types.Toleration, resources types.Resources,
 	securityContext *types.SecurityContext, securityContextConfig SecurityContextConfig,
@@ -45,7 +45,8 @@ func mkPod(namespace, name, image, workDir, goos, serviceAccountName string,
 
 	meta := podMeta(name, namespace, labels, annotations)
 
-	spec, err := podSpec(serviceAccountName, vols, env, nodeSelector, extraHosts, tolerations, securityContext, securityContextConfig)
+	spec, err := podSpec(serviceAccountName, vols, pullSecretNames, env, nodeSelector, extraHosts, tolerations,
+		securityContext, securityContextConfig)
 	if err != nil {
 		return nil, err
 	}
@@ -85,7 +86,7 @@ func podMeta(name, namespace string, labels, annotations map[string]string) meta
 	return meta
 }
 
-func podSpec(serviceAccountName string, vols []string, env, backendNodeSelector map[string]string,
+func podSpec(serviceAccountName string, vols, pullSecretNames []string, env, backendNodeSelector map[string]string,
 	extraHosts []types.HostAlias, backendTolerations []types.Toleration,
 	securityContext *types.SecurityContext, securityContextConfig SecurityContextConfig,
 ) (v1.PodSpec, error) {
@@ -93,7 +94,7 @@ func podSpec(serviceAccountName string, vols []string, env, backendNodeSelector
 	spec := v1.PodSpec{
 		RestartPolicy:      v1.RestartPolicyNever,
 		ServiceAccountName: serviceAccountName,
-		ImagePullSecrets:   []v1.LocalObjectReference{{Name: "regcred"}},
+		ImagePullSecrets:   imagePullSecretsReferences(pullSecretNames),
 	}
 
 	spec.HostAliases = hostAliases(extraHosts)
@@ -211,6 +212,22 @@ func hostAlias(extraHost types.HostAlias) v1.HostAlias {
 	}
 }
 
+func imagePullSecretsReferences(imagePullSecretNames []string) []v1.LocalObjectReference {
+	log.Trace().Msgf("Using the image pull secrets: %v", imagePullSecretNames)
+
+	secretReferences := make([]v1.LocalObjectReference, len(imagePullSecretNames))
+	for i, imagePullSecretName := range imagePullSecretNames {
+		secretReferences[i] = imagePullSecretsReference(imagePullSecretName)
+	}
+	return secretReferences
+}
+
+func imagePullSecretsReference(imagePullSecretName string) v1.LocalObjectReference {
+	return v1.LocalObjectReference{
+		Name: imagePullSecretName,
+	}
+}
+
 func resourceRequirements(resources types.Resources) (v1.ResourceRequirements, error) {
 	var err error
 	requirements := v1.ResourceRequirements{}
@@ -357,7 +374,7 @@ func startPod(ctx context.Context, engine *kube, step *types.Step) (*v1.Pod, err
 
 	pod, err := mkPod(engine.config.Namespace, podName, step.Image, step.WorkingDir, engine.goos, step.BackendOptions.Kubernetes.ServiceAccountName,
 		step.Pull, step.Privileged,
-		step.Commands, step.Volumes,
+		step.Commands, step.Volumes, engine.config.ImagePullSecretNames,
 		engine.config.PodLabels, engine.config.PodAnnotations, step.Environment, step.BackendOptions.Kubernetes.NodeSelector,
 		step.ExtraHosts, step.BackendOptions.Kubernetes.Tolerations, step.BackendOptions.Kubernetes.Resources, step.BackendOptions.Kubernetes.SecurityContext, engine.config.SecurityContext)
 	if err != nil {

pipeline/backend/kubernetes/pod_test.go

@@ -96,19 +96,14 @@ func TestTinyPod(t *testing.T) {
 					]
 				}
 			],
-			"restartPolicy": "Never",
-			"imagePullSecrets": [
-				{
-					"name": "regcred"
-				}
-			]
+			"restartPolicy": "Never"
 		},
 		"status": {}
 	}`
 
 	pod, err := mkPod("woodpecker", "wp-01he8bebctabr3kgk0qj36d2me-0", "gradle:8.4.0-jdk21", "/woodpecker/src", "linux/amd64", "",
 		false, false,
-		[]string{"gradle build"}, []string{"workspace:/woodpecker/src"},
+		[]string{"gradle build"}, []string{"workspace:/woodpecker/src"}, nil,
 		nil, nil, map[string]string{"CI": "woodpecker"}, nil,
 		nil, nil,
 		types.Resources{Requests: nil, Limits: nil}, nil, SecurityContextConfig{},
@@ -213,6 +208,9 @@ func TestFullPod(t *testing.T) {
 			"imagePullSecrets": [
 				{
 					"name": "regcred"
+				},
+				{
+					"name": "another-pull-secret"
 				}
 			],
 			"tolerations": [
@@ -246,7 +244,7 @@ func TestFullPod(t *testing.T) {
 	}
 	pod, err := mkPod("woodpecker", "wp-01he8bebctabr3kgk0qj36d2me-0", "meltwater/drone-cache", "/woodpecker/src", "linux/amd64", "wp-svc-acc",
 		true, true,
-		[]string{"go get", "go test"}, []string{"woodpecker-cache:/woodpecker/src/cache"},
+		[]string{"go get", "go test"}, []string{"woodpecker-cache:/woodpecker/src/cache"}, []string{"regcred", "another-pull-secret"},
 		map[string]string{"app": "test"}, map[string]string{"apparmor.security": "runtime/default"}, map[string]string{"CGO": "0"}, map[string]string{"storage": "ssd"},
 		hostAliases, []types.Toleration{{Key: "net-port", Value: "100Mbit", Effect: types.TaintEffectNoSchedule}},
 		types.Resources{Requests: map[string]string{"memory": "128Mi", "cpu": "1000m"}, Limits: map[string]string{"memory": "256Mi", "cpu": "2"}},