Add support for custom tasks to use workspaces, service accounts, and…

… pod templates.

These features will be needed to build more complex custom tasks.

docs/pipelineruns.md

@@ -258,6 +258,9 @@ set for the target [`namespace`](https://kubernetes.io/docs/concepts/overview/wo
 
 For more information, see [`ServiceAccount`](auth.md).
 
+[`Custom tasks`](pipelines.md#using-custom-tasks) may or may not use a service account name.
+Consult the documentation of the custom task that you are using to determine whether it supports a service account name.
+
 ### Mapping `ServiceAccount` credentials to `Tasks`
 
 If you require more granularity in specifying execution credentials, use the `serviceAccountNames` field to
@@ -341,6 +344,9 @@ spec:
         claimName: my-volume-claim
 ```
 
+[`Custom tasks`](pipelines.md#using-custom-tasks) may or may not use a pod template.
+Consult the documentation of the custom task that you are using to determine whether it supports a pod template.
+
 ### Specifying taskRunSpecs
 
 Specifies a list of `PipelineTaskRunSpec` which contains `TaskServiceAccountName`, `TaskPodTemplate`
@@ -385,6 +391,9 @@ For more information, see the following topics:
 - For a list of supported `Volume` types, see [Specifying `VolumeSources` in `Workspaces`](workspaces.md#specifying-volumesources-in-workspaces).
 - For an end-to-end example, see [`Workspaces` in a `PipelineRun`](../examples/v1beta1/pipelineruns/workspaces.yaml).
 
+[`Custom tasks`](pipelines.md#using-custom-tasks) may or may not use workspaces.
+Consult the documentation of the custom task that you are using to determine whether it supports workspaces.
+
 ### Specifying `LimitRange` values
 
 In order to only consume the bare minimum amount of resources needed to execute one `Step` at a

docs/pipelines.md

@@ -954,13 +954,12 @@ If the `taskRef` specifies a name, the custom task controller should look up the
 If the `taskRef` does not specify a name, the custom task controller might support
 some default behavior for executing unnamed tasks.
 
-### Specifying `Parameters`
+### Specifying parameters
 
 If a custom task supports [`parameters`](tasks.md#parameters), you can use the
 `params` field to specify their values:
 
 ```yaml
-spec:
 spec:
   tasks:
     - name: run-custom-task
@@ -973,21 +972,36 @@ spec:
         value: bah
 ```
 
+### Specifying workspaces
+
+If the custom task supports it, you can provide [`Workspaces`](workspaces.md#using-workspaces-in-tasks) to share data with the custom task.
+
+```yaml
+spec:
+  tasks:
+    - name: run-custom-task
+      taskRef:
+        apiVersion: example.dev/v1alpha1
+        kind: Example
+        name: myexample
+      workspaces:
+      - name: my-workspace
+```
+
+Consult the documentation of the custom task that you are using to determine whether it supports workspaces and how to name them.
+
 ### Using `Results`
 
 If the custom task produces results, you can reference them in a Pipeline using the normal syntax,
 `$(tasks.<task-name>.results.<result-name>)`.
 
 ### Limitations
 
-Pipelines do not directly support passing the following items to custom tasks:
+Pipelines do not support the following items with custom tasks:
 * Pipeline Resources
-* Workspaces
-* Service account name
-* Pod templates
-
-A pipeline task that references a custom task cannot reference `Conditions`.
-`Conditions` are deprecated.  Use [`WhenExpressions`](#guard-task-execution-using-whenexpressions) instead.
+* [`retries`](#using-the-retries-parameter)
+* [`timeout`](#configuring-the-failure-timeout)
+* Conditions (`Conditions` are deprecated.  Use [`WhenExpressions`](#guard-task-execution-using-whenexpressions) instead.)
 
 ## Code examples
 

docs/runs.md

@@ -10,7 +10,8 @@ weight: 2
 - [Overview](#overview)
 - [Configuring a `Run`](#configuring-a-run)
   - [Specifying the target Custom Task](#specifying-the-target-custom-task)
-  - [Specifying `Parameters`](#specifying-parameters)
+  - [Specifying Parameters](#specifying-parameters)
+  - [Specifying Workspaces, Service Account, and Pod Template](#specifying-workspaces-service-account-and-pod-template)
 - [Monitoring execution status](#monitoring-execution-status)
   - [Monitoring `Results`](#monitoring-results)
 - [Code examples](#code-examples)
@@ -51,6 +52,12 @@ A `Run` definition supports the following fields:
 - Optional:
   - [`params`](#specifying-parameters) - Specifies the desired execution
     parameters for the custom task.
+  - [`serviceAccountName`](#specifying-a-serviceaccount) - Specifies a `ServiceAccount`
+    object that provides custom credentials for executing the `Run`.
+  - [`workspaces`](#specifying-workspaces) - Specifies the physical volumes to use for the
+    [`Workspaces`](workspaces.md) required by a custom task.
+  - [`podTemplate`](#specifying-a-pod-template) - Specifies a [`Pod` template](podtemplates.md) to use
+    to configure pods created by the custom task.
 
 [kubernetes-overview]:
   https://kubernetes.io/docs/concepts/overview/working-with-objects/kubernetes-objects/#required-fields
@@ -108,6 +115,57 @@ If the custom task controller knows how to interpret the parameter value, it
 will do so. It might enforce that some parameter values must be specified, or
 reject unknown parameter values.
 
+### Specifying Workspaces, Service Account, and Pod Template
+
+A `Run` object can specify workspaces, a service account name, or a pod template.
+These are intended to be used with custom tasks that create Pods or other resources that embed a Pod specification.
+The custom task can use these specifications to construct the Pod specification.
+Not all custom tasks will support these values.
+Consult the documentation of the custom task that you are using to determine whether these values apply.
+
+#### Specifying workspaces
+
+If the custom task supports it, you can provide [`Workspaces`](workspaces.md) to share data with the custom task.
+
+```yaml
+spec:
+  workspaces:
+  - name: my-workspace
+    emptyDir: {}
+```
+
+Consult the documentation of the custom task that you are using to determine whether it supports workspaces and how to name them.
+
+#### Specifying a ServiceAccount
+
+If the custom task supports it, you can execute the `Run` with a specific set of credentials by
+specifying a `ServiceAccount` object name in the `serviceAccountName` field in your `Run`
+definition. If you do not explicitly specify this, the `Run` executes with the service account
+specified in the `configmap-defaults` `ConfigMap`. If this default is not specified, `Runs`
+will execute with the [`default` service account](https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/#use-the-default-service-account-to-access-the-api-server)
+set for the target [`namespace`](https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/).
+
+```yaml
+spec:
+  serviceAccountName: my-account
+```
+
+Consult the documentation of the custom task that you are using to determine whether it supports a service account name.
+
+#### Specifying a pod template
+
+If the custom task supports it, you can specify a [`Pod` template](podtemplates.md) configuration that the custom task will
+use to configure Pods (or other resources that embed a Pod specification) that it creates.
+
+```yaml
+spec:
+  podTemplate:
+    securityContext:
+      runAsUser: 1001
+```
+
+Consult the documentation of the custom task that you are using to determine whether it supports a pod template.
+
 ## Monitoring execution status
 
 As your `Run` executes, its `status` field accumulates information on the

pkg/apis/pipeline/v1alpha1/run_defaults.go

@@ -19,6 +19,7 @@ package v1alpha1
 import (
 	"context"
 
+	"github.com/tektoncd/pipeline/pkg/apis/config"
 	"knative.dev/pkg/apis"
 )
 
@@ -30,5 +31,13 @@ func (r *Run) SetDefaults(ctx context.Context) {
 }
 
 func (rs *RunSpec) SetDefaults(ctx context.Context) {
-	// No defaults to set.
+	cfg := config.FromContextOrDefaults(ctx)
+	defaultSA := cfg.Defaults.DefaultServiceAccount
+	if rs.ServiceAccountName == "" && defaultSA != "" {
+		rs.ServiceAccountName = defaultSA
+	}
+	defaultPodTemplate := cfg.Defaults.DefaultPodTemplate
+	if rs.PodTemplate == nil {
+		rs.PodTemplate = defaultPodTemplate
+	}
 }

pkg/apis/pipeline/v1alpha1/run_types.go

@@ -48,10 +48,20 @@ type RunSpec struct {
 	// +optional
 	Status RunSpecStatus `json:"status,omitempty"`
 
+	// +optional
+	ServiceAccountName string `json:"serviceAccountName"`
+
+	// PodTemplate holds pod specific configuration
+	// +optional
+	PodTemplate *PodTemplate `json:"podTemplate,omitempty"`
+
+	// Workspaces is a list of WorkspaceBindings from volumes to workspaces.
+	// +optional
+	Workspaces []v1beta1.WorkspaceBinding `json:"workspaces,omitempty"`
+
 	// TODO(https://github.com/tektoncd/community/pull/128)
 	// - timeout
 	// - inline task spec
-	// - workspaces ?
 }
 
 // RunSpecStatus defines the taskrun spec status the user can provide

pkg/apis/pipeline/v1alpha1/run_validation.go

@@ -54,5 +54,9 @@ func (rs *RunSpec) Validate(ctx context.Context) *apis.FieldError {
 		return err
 	}
 
+	if err := validateWorkspaceBindings(ctx, rs.Workspaces); err != nil {
+		return err
+	}
+
 	return nil
 }

pkg/apis/pipeline/v1alpha1/run_validation_test.go

@@ -24,6 +24,7 @@ import (
 	"github.com/tektoncd/pipeline/pkg/apis/pipeline/v1alpha1"
 	v1beta1 "github.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1"
 	"github.com/tektoncd/pipeline/test/diff"
+	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"knative.dev/pkg/apis"
 )
@@ -145,6 +146,20 @@ func TestRun_Valid(t *testing.T) {
 				}},
 			},
 		},
+	}, {
+		name: "valid workspace",
+		run: &v1alpha1.Run{
+			Spec: v1alpha1.RunSpec{
+				Ref: &v1alpha1.TaskRef{
+					APIVersion: "blah",
+					Kind:       "blah",
+				},
+				Workspaces: []v1beta1.WorkspaceBinding{{
+					Name:     "workspace",
+					EmptyDir: &corev1.EmptyDirVolumeSource{},
+				}},
+			},
+		},
 	}} {
 		t.Run(c.name, func(t *testing.T) {
 			if err := c.run.Validate(context.Background()); err != nil {
@@ -153,3 +168,56 @@ func TestRun_Valid(t *testing.T) {
 		})
 	}
 }
+
+func TestRun_Workspaces_Invalid(t *testing.T) {
+	tests := []struct {
+		name    string
+		run     *v1alpha1.Run
+		wantErr *apis.FieldError
+	}{{
+		name: "make sure WorkspaceBinding validation invoked",
+		run: &v1alpha1.Run{
+			Spec: v1alpha1.RunSpec{
+				Ref: &v1alpha1.TaskRef{
+					APIVersion: "blah",
+					Kind:       "blah",
+				},
+				Workspaces: []v1beta1.WorkspaceBinding{{
+					Name: "workspace",
+					PersistentVolumeClaim: &corev1.PersistentVolumeClaimVolumeSource{
+						ClaimName: "",
+					},
+				}},
+			},
+		},
+		wantErr: apis.ErrMissingField("workspace.persistentvolumeclaim.claimname"),
+	}, {
+		name: "bind same workspace twice",
+		run: &v1alpha1.Run{
+			Spec: v1alpha1.RunSpec{
+				Ref: &v1alpha1.TaskRef{
+					APIVersion: "blah",
+					Kind:       "blah",
+				},
+				Workspaces: []v1beta1.WorkspaceBinding{{
+					Name:     "workspace",
+					EmptyDir: &corev1.EmptyDirVolumeSource{},
+				}, {
+					Name:     "workspace",
+					EmptyDir: &corev1.EmptyDirVolumeSource{},
+				}},
+			},
+		},
+		wantErr: apis.ErrMultipleOneOf("spec.workspaces.name"),
+	}}
+	for _, ts := range tests {
+		t.Run(ts.name, func(t *testing.T) {
+			err := ts.run.Validate(context.Background())
+			if err == nil {
+				t.Errorf("Expected error for invalid Run but got none")
+			} else if d := cmp.Diff(ts.wantErr.Error(), err.Error()); d != "" {
+				t.Errorf("Did not get expected error for %q: %s", ts.name, diff.PrintWantGot(d))
+			}
+		})
+	}
+}

pkg/apis/pipeline/v1beta1/pipeline_validation.go

@@ -156,9 +156,6 @@ func validatePipelineTask(ctx context.Context, t PipelineTask, taskNames sets.St
 		if t.Resources != nil {
 			errs = errs.Also(apis.ErrInvalidValue("custom tasks do not support PipelineResources", "resources"))
 		}
-		if len(t.Workspaces) > 0 {
-			errs = errs.Also(apis.ErrInvalidValue("custom tasks do not support Workspaces", "workspaces"))
-		}
 		if t.Timeout != nil {
 			errs = errs.Also(apis.ErrInvalidValue("custom tasks do not support timeout", "timeout"))
 		}

pkg/apis/pipeline/v1beta1/pipeline_validation_test.go

@@ -620,18 +620,6 @@ func TestValidatePipelineTasks_Failure(t *testing.T) {
 			Paths:   []string{"tasks[0].resources"},
 		},
 		wc: enableFeature(t, "enable-custom-tasks"),
-	}, {
-		name: "pipelinetask custom task doesn't support workspaces",
-		tasks: []PipelineTask{{
-			Name:       "foo",
-			Workspaces: []WorkspacePipelineTaskBinding{{}},
-			TaskRef:    &TaskRef{APIVersion: "example.dev/v0", Kind: "Example"},
-		}},
-		expectedError: apis.FieldError{
-			Message: `invalid value: custom tasks do not support Workspaces`,
-			Paths:   []string{"tasks[0].workspaces"},
-		},
-		wc: enableFeature(t, "enable-custom-tasks"),
 	}, {
 		name: "pipelinetask custom task doesn't support timeout",
 		tasks: []PipelineTask{{