adding finally type at the pipeline level

these changes are adding finally type and its validation, does not
implement this new functionality.

docs/pipelines.md

@@ -21,6 +21,7 @@ weight: 3
   - [Configuring execution results at the `Pipeline` level](#configuring-execution-results-at-the-pipeline-level)
   - [Configuring the `Task` execution order](#configuring-the-task-execution-order)
   - [Adding a description](#adding-a-description)
+  - [Adding `Finally` to the `Pipeline` (Preview)](#adding-finally-to-the-pipeline-preview)
   - [Code examples](#code-examples)
 
 ## Overview
@@ -529,6 +530,34 @@ In particular:
 
 The `description` field is an optional field and can be used to provide description of the `Pipeline`.
 
+## Adding `Finally` to the `Pipeline` (Preview)
+
+_Finally type is available in the `Pipeline` but functionality is in progress. Final tasks are can be sepcified and
+are validated but not executed yet._
+
+You can specify a list of one or more final tasks under `finally` section. Final tasks are guaranteed to be executed
+in parallel after all `PipelineTasks` under `tasks` have completed regardless of success or error. Final tasks are very
+similar to `PipelineTasks` under `tasks` section and follow the same syntax. Each final task must have a
+[valid](https://kubernetes.io/docs/concepts/overview/working-with-objects/names/#names) `name` and a [taskRef or
+taskSpec](taskruns.md#specifying-the-target-task). For example:
+
+```yaml
+spec:
+  tasks:
+    - name: tests
+      taskRef:
+        Name: integration-test
+  finally:
+    - name: cleanup-test
+      taskRef:
+        Name: cleanup
+```
+
+_[PR #2661](https://github.com/tektoncd/pipeline/pull/2661) is implementing this new functionality by adding support to enable
+final tasks along with workspaces and parameters. `PipelineRun` status is being updated to include execution status of
+final tasks i.e. `PipelineRun` status is set to success or failure depending on execution of `PipelineTasks`, this status
+remains same when all final tasks finishes successfully but is set to failure if any of the final tasks fail._
+
 ## Code examples
 
 For a better understanding of `Pipelines`, study [our code examples](https://github.com/tektoncd/pipeline/tree/master/examples).

pkg/apis/pipeline/v1alpha1/conversion_error.go

@@ -26,6 +26,8 @@ const (
 	// resources when they cannot be converted to warn of a forthcoming
 	// breakage.
 	ConditionTypeConvertible apis.ConditionType = v1beta1.ConditionTypeConvertible
+	// Conversion Error message for a field not available in v1alpha1
+	ConversionErrorFieldNotAvailableMsg = "the specified field/section is not available in v1alpha1"
 )
 
 // CannotConvertError is returned when a field cannot be converted.

pkg/apis/pipeline/v1alpha1/pipeline_conversion.go

@@ -25,6 +25,8 @@ import (
 	"knative.dev/pkg/apis"
 )
 
+const FinallyFieldName = "finally"
+
 var _ apis.Convertible = (*Pipeline)(nil)
 
 // ConvertTo implements api.Convertible
@@ -51,6 +53,7 @@ func (source *PipelineSpec) ConvertTo(ctx context.Context, sink *v1beta1.Pipelin
 			}
 		}
 	}
+	sink.Finally = nil
 	return nil
 }
 
@@ -97,6 +100,10 @@ func (sink *PipelineSpec) ConvertFrom(ctx context.Context, source v1beta1.Pipeli
 			}
 		}
 	}
+	// finally clause was introduced in v1beta1 and not available in v1alpha1
+	if len(source.Finally) > 0 {
+		return ConvertErrorf(FinallyFieldName, ConversionErrorFieldNotAvailableMsg)
+	}
 	return nil
 }
 

pkg/apis/pipeline/v1alpha1/pipeline_conversion_test.go

@@ -42,13 +42,12 @@ func TestPipelineConversionBadType(t *testing.T) {
 	}
 }
 
-func TestPipelineConversion(t *testing.T) {
+func TestPipelineConversion_Success(t *testing.T) {
 	versions := []apis.Convertible{&v1beta1.Pipeline{}}
 
 	tests := []struct {
-		name    string
-		in      *Pipeline
-		wantErr bool
+		name string
+		in   *Pipeline
 	}{{
 		name: "simple conversion",
 		in: &Pipeline{
@@ -114,7 +113,38 @@ func TestPipelineConversion(t *testing.T) {
 				}},
 			},
 		},
-	}, {
+	}}
+
+	for _, test := range tests {
+		for _, version := range versions {
+			t.Run(test.name, func(t *testing.T) {
+				ver := version
+				// convert v1alpha1 Pipeline to v1beta1 Pipeline
+				if err := test.in.ConvertTo(context.Background(), ver); err != nil {
+					t.Errorf("ConvertTo() = %v", err)
+				}
+				got := &Pipeline{}
+				// converting it back to v1alpha1 pipeline and storing it in got variable to compare with original input
+				if err := got.ConvertFrom(context.Background(), ver); err != nil {
+					t.Errorf("ConvertFrom() = %v", err)
+				}
+				// compare origin input and roundtrip Pipeline i.e. v1alpha1 pipeline converted to v1beta1 and then converted back to v1alpha1
+				// this check is making sure that we do not end up with different object than what we started with
+				if d := cmp.Diff(test.in, got); d != "" {
+					t.Errorf("roundtrip %s", diff.PrintWantGot(d))
+				}
+			})
+		}
+	}
+}
+
+func TestPipelineConversion_Failure(t *testing.T) {
+	versions := []apis.Convertible{&v1beta1.Pipeline{}}
+
+	tests := []struct {
+		name string
+		in   *Pipeline
+	}{{
 		name: "simple conversion with task spec error",
 		in: &Pipeline{
 			ObjectMeta: metav1.ObjectMeta{
@@ -152,29 +182,76 @@ func TestPipelineConversion(t *testing.T) {
 				}},
 			},
 		},
-		wantErr: true,
 	}}
-
 	for _, test := range tests {
 		for _, version := range versions {
 			t.Run(test.name, func(t *testing.T) {
 				ver := version
-				if err := test.in.ConvertTo(context.Background(), ver); err != nil {
-					if !test.wantErr {
-						t.Errorf("ConvertTo() = %v", err)
-					}
-					return
-				}
-				t.Logf("ConvertTo() = %#v", ver)
-				got := &Pipeline{}
-				if err := got.ConvertFrom(context.Background(), ver); err != nil {
-					t.Errorf("ConvertFrom() = %v", err)
-				}
-				t.Logf("ConvertFrom() = %#v", got)
-				if d := cmp.Diff(test.in, got); d != "" {
-					t.Errorf("roundtrip %s", diff.PrintWantGot(d))
+				if err := test.in.ConvertTo(context.Background(), ver); err == nil {
+					t.Errorf("Expected ConvertTo to fail but did not produce any error")
 				}
+				return
 			})
 		}
 	}
 }
+
+func TestPipelineConversionFromWithFinally(t *testing.T) {
+	versions := []apis.Convertible{&v1beta1.Pipeline{}}
+	p := &Pipeline{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "foo",
+			Namespace:  "bar",
+			Generation: 1,
+		},
+		Spec: PipelineSpec{
+			Tasks: []PipelineTask{{Name: "mytask", TaskRef: &TaskRef{Name: "task"}}},
+		},
+	}
+	for _, version := range versions {
+		t.Run("finally not available in v1alpha1", func(t *testing.T) {
+			ver := version
+			// convert v1alpha1 to v1beta1
+			if err := p.ConvertTo(context.Background(), ver); err != nil {
+				t.Errorf("ConvertTo() = %v", err)
+			}
+			// modify ver to introduce new field which causes failure to convert v1beta1 to v1alpha1
+			source := ver
+			source.(*v1beta1.Pipeline).Spec.Finally = []v1beta1.PipelineTask{{Name: "finaltask", TaskRef: &TaskRef{Name: "task"}}}
+			got := &Pipeline{}
+			if err := got.ConvertFrom(context.Background(), source); err != nil {
+				cce, ok := err.(*CannotConvertError)
+				// conversion error contains the field name which resulted in the failure and should be equal to "Finally" here
+				if ok && cce.Field == FinallyFieldName {
+					return
+				}
+				t.Errorf("ConvertFrom() should have failed")
+			}
+		})
+	}
+}
+
+func TestPipelineConversionFromBetaToAlphaWithFinally_Failure(t *testing.T) {
+	p := &v1beta1.Pipeline{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:       "foo",
+			Namespace:  "bar",
+			Generation: 1,
+		},
+		Spec: v1beta1.PipelineSpec{
+			Tasks:   []v1beta1.PipelineTask{{Name: "mytask", TaskRef: &TaskRef{Name: "task"}}},
+			Finally: []v1beta1.PipelineTask{{Name: "mytask", TaskRef: &TaskRef{Name: "task"}}},
+		},
+	}
+	t.Run("finally not available in v1alpha1", func(t *testing.T) {
+		got := &Pipeline{}
+		if err := got.ConvertFrom(context.Background(), p); err != nil {
+			cce, ok := err.(*CannotConvertError)
+			// conversion error (cce) contains the field name which resulted in the failure and should be equal to "finally" here
+			if ok && cce.Field == FinallyFieldName {
+				return
+			}
+			t.Errorf("ConvertFrom() should have failed")
+		}
+	})
+}

pkg/apis/pipeline/v1beta1/pipeline_defaults.go

@@ -42,4 +42,14 @@ func (ps *PipelineSpec) SetDefaults(ctx context.Context) {
 	for i := range ps.Params {
 		ps.Params[i].SetDefaults(ctx)
 	}
+	for _, ft := range ps.Finally {
+		if ft.TaskRef != nil {
+			if ft.TaskRef.Kind == "" {
+				ft.TaskRef.Kind = NamespacedTaskKind
+			}
+		}
+		if ft.TaskSpec != nil {
+			ft.TaskSpec.SetDefaults(ctx)
+		}
+	}
 }

pkg/apis/pipeline/v1beta1/pipeline_defaults_test.go

@@ -0,0 +1,138 @@
+/*
+Copyright 2020 The Tekton Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1beta1_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/tektoncd/pipeline/test/diff"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1"
+)
+
+func TestPipeline_SetDefaults(t *testing.T) {
+	p := &v1beta1.Pipeline{}
+	want := &v1beta1.Pipeline{}
+	t.Run("set defaults for empty pipeline", func(t *testing.T) {
+		ctx := context.Background()
+		p.SetDefaults(ctx)
+		if d := cmp.Diff(want, p); d != "" {
+			t.Errorf("Mismatch of Pipeline: empty pipeline must not change after setting defaults: %s", diff.PrintWantGot(d))
+		}
+	})
+}
+
+func TestPipelineSpec_SetDefaults(t *testing.T) {
+	cases := []struct {
+		desc string
+		ps   *v1beta1.PipelineSpec
+		want *v1beta1.PipelineSpec
+	}{{
+		desc: "empty pipelineSpec must not change after setting defaults",
+		ps:   &v1beta1.PipelineSpec{},
+		want: &v1beta1.PipelineSpec{},
+	}, {
+		desc: "pipeline task - default task kind must be " + string(v1beta1.NamespacedTaskKind),
+		ps: &v1beta1.PipelineSpec{
+			Tasks: []v1beta1.PipelineTask{{
+				Name: "foo", TaskRef: &v1beta1.TaskRef{Name: "foo-task"},
+			}},
+		},
+		want: &v1beta1.PipelineSpec{
+			Tasks: []v1beta1.PipelineTask{{
+				Name: "foo", TaskRef: &v1beta1.TaskRef{Name: "foo-task", Kind: v1beta1.NamespacedTaskKind},
+			}},
+		},
+	}, {
+		desc: "final pipeline task - default task kind must be " + string(v1beta1.NamespacedTaskKind),
+		ps: &v1beta1.PipelineSpec{
+			Finally: []v1beta1.PipelineTask{{
+				Name: "final-task", TaskRef: &v1beta1.TaskRef{Name: "foo-task"},
+			}},
+		},
+		want: &v1beta1.PipelineSpec{
+			Finally: []v1beta1.PipelineTask{{
+				Name: "final-task", TaskRef: &v1beta1.TaskRef{Name: "foo-task", Kind: v1beta1.NamespacedTaskKind},
+			}},
+		},
+	}, {
+		desc: "param type - default param type must be " + string(v1beta1.ParamTypeString),
+		ps: &v1beta1.PipelineSpec{
+			Params: []v1beta1.ParamSpec{{
+				Name: "string-param",
+			}},
+		},
+		want: &v1beta1.PipelineSpec{
+			Params: []v1beta1.ParamSpec{{
+				Name: "string-param", Type: v1beta1.ParamTypeString,
+			}},
+		},
+	}, {
+		desc: "pipeline task with taskSpec - default param type must be " + string(v1beta1.ParamTypeString),
+		ps: &v1beta1.PipelineSpec{
+			Tasks: []v1beta1.PipelineTask{{
+				Name: "foo", TaskSpec: &v1beta1.TaskSpec{
+					Params: []v1beta1.ParamSpec{{
+						Name: "string-param",
+					}},
+				},
+			}},
+		},
+		want: &v1beta1.PipelineSpec{
+			Tasks: []v1beta1.PipelineTask{{
+				Name: "foo", TaskSpec: &v1beta1.TaskSpec{
+					Params: []v1beta1.ParamSpec{{
+						Name: "string-param",
+						Type: v1beta1.ParamTypeString,
+					}},
+				},
+			}},
+		},
+	}, {
+		desc: "final pipeline task with taskSpec - default param type must be " + string(v1beta1.ParamTypeString),
+		ps: &v1beta1.PipelineSpec{
+			Finally: []v1beta1.PipelineTask{{
+				Name: "foo", TaskSpec: &v1beta1.TaskSpec{
+					Params: []v1beta1.ParamSpec{{
+						Name: "string-param",
+					}},
+				},
+			}},
+		},
+		want: &v1beta1.PipelineSpec{
+			Finally: []v1beta1.PipelineTask{{
+				Name: "foo", TaskSpec: &v1beta1.TaskSpec{
+					Params: []v1beta1.ParamSpec{{
+						Name: "string-param",
+						Type: v1beta1.ParamTypeString,
+					}},
+				},
+			}},
+		},
+	}}
+	for _, tc := range cases {
+		t.Run(tc.desc, func(t *testing.T) {
+			ctx := context.Background()
+			tc.ps.SetDefaults(ctx)
+			if d := cmp.Diff(tc.want, tc.ps); d != "" {
+				t.Errorf("Mismatch of pipelineSpec after setting defaults: %s: %s", tc.desc, diff.PrintWantGot(d))
+			}
+		})
+	}
+}

pkg/apis/pipeline/v1beta1/pipeline_types.go

@@ -71,6 +71,10 @@ type PipelineSpec struct {
 	// Results are values that this pipeline can output once run
 	// +optional
 	Results []PipelineResult `json:"results,omitempty"`
+	// Finally declares the list of Tasks that execute just before leaving the Pipeline
+	// i.e. either after all Tasks are finished executing successfully
+	// or after a failure which would result in ending the Pipeline
+	Finally []PipelineTask `json:"finally,omitempty"`
 }
 
 // PipelineResult used to describe the results of a pipeline