Support for k8s serviceAccount and nodeSelector (#1842)

Add the possiblity to specify the Kubernetes serviceAccount and/or
nodeSelector to be used on individual steps for Kubernetes executor

docs/docs/30-administration/22-backends/40-kubernetes.md

@@ -40,9 +40,23 @@ Additional labels to apply to worker pods. Must be a YAML object, e.g. `{"exampl
 
 Additional annotations to apply to worker pods. Must be a YAML object, e.g. `{"example.com/test-annotation":"test-value"}`.
 
-## Resources
+## Job specific configuration
+
+### Resources
 
 The kubernetes backend also allows for specifying requests and limits on a per-step basic, most commonly for CPU and memory.
+See the [kubernetes documentation](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/) for more information on using resources.
+
+### serviceAccountName
+
+Specify the name of the ServiceAccount which the build pod will mount. This serviceAccount must be created externally.
+See the [kubernetes documentation](https://kubernetes.io/docs/concepts/security/service-accounts/) for more information on using serviceAccounts.
+
+### nodeSelector
+
+Specify the label which is used to select the node where the job should be executed. Labels defined here will be appended to a list already containing "kubernetes.io/arch".
+By default the pod will use "kubernetes.io/arch" inferred from top-level "platform" setting which is deducted from the agents' environment variable CI_SYSTEM_ARCH. To overwrite this, you need to specify this label in the nodeSelector section.
+See the [kubernetes documentation](https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#nodeselector) for more information on using nodeSelector.
 
 Example pipeline configuration:
 ```yaml
@@ -55,12 +69,13 @@ steps:
       - go test
     backend_options:
       kubernetes:
+        serviceAccountName: 'my-service-account'
         resources:
           requests:
             memory: 128Mi
             cpu: 1000m
           limits:
             memory: 256Mi
+        nodeSelector:
+          beta.kubernetes.io/instance-type: p3.8xlarge
 ```
-
-See the [kubernetes documentation](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/) for more information on using resources.

pipeline/backend/kubernetes/pod.go

@@ -80,6 +80,11 @@ func Pod(namespace string, step *types.Step, labels, annotations map[string]stri
 		}
 	}
 
+	var ServiceAccountName string
+	if step.BackendOptions.Kubernetes.ServiceAccountName != "" {
+		ServiceAccountName = step.BackendOptions.Kubernetes.ServiceAccountName
+	}
+
 	podName, err := dnsName(step.Name)
 	if err != nil {
 		return nil, err
@@ -97,6 +102,10 @@ func Pod(namespace string, step *types.Step, labels, annotations map[string]stri
 
 	NodeSelector := map[string]string{"kubernetes.io/arch": strings.Split(platform, "/")[1]}
 
+	for key, val := range step.BackendOptions.Kubernetes.NodeSelector {
+		NodeSelector[key] = val
+	}
+
 	pod := &v1.Pod{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:        podName,
@@ -105,9 +114,10 @@ func Pod(namespace string, step *types.Step, labels, annotations map[string]stri
 			Annotations: annotations,
 		},
 		Spec: v1.PodSpec{
-			RestartPolicy: v1.RestartPolicyNever,
+			RestartPolicy:      v1.RestartPolicyNever,
-			HostAliases:   hostAliases,
+			HostAliases:        hostAliases,
-			NodeSelector:  NodeSelector,
+			NodeSelector:       NodeSelector,
+			ServiceAccountName: ServiceAccountName,
 			Containers: []v1.Container{{
 				Name:            podName,
 				Image:           step.Image,

pipeline/backend/types/backend_kubernetes.go

@@ -2,7 +2,9 @@ package types
 
 // KubernetesBackendOptions defines all the advanced options for the kubernetes backend
 type KubernetesBackendOptions struct {
-	Resources Resources `json:"resouces,omitempty"`
+	Resources          Resources         `json:"resouces,omitempty"`
+	ServiceAccountName string            `json:"serviceAccountName,omitempty"`
+	NodeSelector       map[string]string `json:"nodeSelector,omitempty"`
 }
 
 // Resources defines two maps for kubernetes resource definitions

pipeline/frontend/yaml/compiler/convert.go

@@ -116,6 +116,8 @@ func (c *Compiler) createProcess(name string, container *yaml_types.Container, s
 				Limits:   container.BackendOptions.Kubernetes.Resources.Limits,
 				Requests: container.BackendOptions.Kubernetes.Resources.Requests,
 			},
+			ServiceAccountName: container.BackendOptions.Kubernetes.ServiceAccountName,
+			NodeSelector:       container.BackendOptions.Kubernetes.NodeSelector,
 		},
 	}
 

pipeline/frontend/yaml/types/backend_options.go

@@ -20,7 +20,9 @@ type BackendOptions struct {
 }
 
 type KubernetesBackendOptions struct {
-	Resources Resources `yaml:"resources,omitempty"`
+	Resources          Resources         `yaml:"resources,omitempty"`
+	ServiceAccountName string            `yaml:"serviceAccountName,omitempty"`
+	NodeSelector       map[string]string `yaml:"nodeSelector,omitempty"`
 }
 
 type Resources struct {

pipeline/schema/schema.json

@@ -521,6 +521,25 @@
         "type": "string"
       }
     },
+    "step_backend_kubernetes_service_account": {
+      "description": "serviceAccountName to be use by job. Read more: https://woodpecker-ci.org/docs/administration/backends/kubernetes",
+      "type": "object",
+      "properties": {
+        "requests": {
+          "$ref": "#/definitions/step_kubernetes_service_account_object"
+        },
+        "limits": {
+          "$ref": "#/definitions/step_kubernetes_service_account_object"
+        }
+      }
+    },
+    "step_kubernetes_service_account_object": {
+      "description": "A list of kubernetes resource mappings",
+      "type": "object",
+      "additionalProperties": {
+        "type": "string"
+      }
+    },
     "services": {
       "description": "Read more: https://woodpecker-ci.org/docs/usage/services",
       "type": "object",