Add pipeline results

docs/pipelineruns.md

@@ -92,7 +92,6 @@ spec:
 [Here](../examples/v1beta1/pipelineruns/pipelinerun-with-pipelinespec.yaml) is a sample `PipelineRun` to display different
 greetings while embedding the spec of the `Pipeline` directly in the `PipelineRun`.
 
-
 After creating such a `PipelineRun`, the logs from this pod are displaying morning greetings:
 
 ```bash
@@ -101,6 +100,7 @@ Good Morning, Bob!
 ```
 
 And the logs from this pod are displaying evening greetings:
+
 ```bash
 kubectl logs $(kubectl get pods -o name | grep pipelinerun-echo-greetings-echo-good-night)
 Good Night, Bob!
@@ -121,7 +121,6 @@ spec:
 [Here](../examples/v1beta1/pipelineruns/pipelinerun-with-pipelinespec-and-taskspec.yaml) is a sample `PipelineRun` with embedded
 the spec of the `Pipeline` directly in the `PipelineRun` along with the spec of the `Task` under `PipelineSpec`.
 
-
 ### Resources
 
 When running a [`Pipeline`](pipelines.md), you will need to specify the
@@ -154,7 +153,6 @@ spec:
 
 Or you can embed the spec of the `Resource` directly in the `PipelineRun`:
 
-
 ```yaml
 spec:
   resources:
@@ -224,6 +222,7 @@ spec:
     - taskName: build-task
       serviceAccountName: sa-for-build
 ```
+
 If used with this `Pipeline`, `test-task` will use the `ServiceAccount` `sa-1`, while `build-task` will use `sa-for-build`.
 
 ```yaml

docs/pipelines.md

@@ -65,6 +65,7 @@ following fields:
         fail. There is no default timeout for a Pipeline Task timeout. If no timeout is specified for
         the Pipeline Task, the only timeout taken into account for running a `Pipeline` will be a
         [timeout for the `PipelineRun`](https://github.com/tektoncd/pipeline/blob/master/docs/pipelineruns.md#syntax).
+  - [`results`](#pipeline-results) - Specifies which `results` is defined for the pipeline
 
 [kubernetes-overview]:
   https://kubernetes.io/docs/concepts/overview/working-with-objects/kubernetes-objects/#required-fields
@@ -419,7 +420,7 @@ spec:
 The Timeout property is specified as part of the Pipeline Task on the `Pipeline` spec. The above
 example has a timeout of one minute and 30 seconds.
 
-### Results
+#### Results
 
 Tasks can declare [results](./tasks.md#results) that they will emit during their execution. These results can be used as values for params in subsequent tasks of a Pipeline. Tekton will infer the ordering of these Tasks to ensure that the Task emitting the results runs before the Task consuming those results in its parameters.
 
@@ -435,7 +436,7 @@ In this example the previous pipeline task has name "previous-task-name" and its
 
 For a complete example demonstrating Task Results in a Pipeline see the [pipelinerun example](../examples/v1beta1/pipelineruns/task_results_example.yaml).
 
-### Ordering
+#### Ordering
 
 The [Pipeline Tasks](#pipeline-tasks) in a `Pipeline` can be connected and run
 in a graph, specifically a _Directed Acyclic Graph_ or DAG. Each of the Pipeline
@@ -528,6 +529,22 @@ build-app  build-frontend
 1. The entire `Pipeline` will be finished executing after `lint-repo` and
    `deploy-all` have completed.
 
+### Pipeline Results
+
+A pipeline can declare results that they will emit during their execution. These results can be defined as reference to task results executed
+during the pipeline execution.
+
+```yaml
+  results:
+    - name: sum
+      description: the sum of all three operands
+      value: $(tasks.second-add.results.sum)
+```
+
+In this example the pipeline result has name "sum" and its result is declared as the task result value from the tasks named `second-add`.
+
+For a complete example demonstrating pipeline Results in a Pipeline see the [pipeline example](../examples/pipelineruns/pipelinerun-results.yaml).
+
 ## Examples
 
 For complete examples, see

examples/v1beta1/pipelineruns/pipelinerun-results.yaml

@@ -0,0 +1,79 @@
+apiVersion: tekton.dev/v1beta1
+kind: Task
+metadata:
+  name: add-task
+spec:
+  params:
+    - name: first
+      description: the first operand
+    - name: second
+      description: the second operand
+  results:
+    - name: sum
+      description: the sum of the first and second operand
+  steps:
+    - name: add
+      image: alpine
+      env:
+        - name: OP1
+          value: $(params.first)
+        - name: OP2
+          value: $(params.second)
+      command: ["/bin/sh", "-c"]
+      args:
+        - echo -n $((${OP1}+${OP2})) | tee $(results.sum.path);
+---
+apiVersion: tekton.dev/v1beta1
+kind: Pipeline
+metadata:
+  name: sum-three-pipeline
+spec:
+  params:
+    - name: first
+      description: the first operand
+    - name: second
+      description: the second operand
+    - name: third
+      description: the third operand
+  tasks:
+    - name: first-add
+      taskRef:
+        name: add-task
+      params:
+        - name: first
+          value: $(params.first)
+        - name: second
+          value: $(params.second)
+    - name: second-add
+      taskRef:
+        name: add-task
+      params:
+        - name: first
+          value: $(tasks.first-add.results.sum)
+        - name: second
+          value: $(params.third)
+  results:
+    - name: sum
+      description: the sum of all three operands
+      value: $(tasks.second-add.results.sum)
+    - name: partial-sum
+      description: the sum of first two operands
+      value: $(tasks.first-add.results.sum)
+    - name: all-sum
+      description: the sum of everything
+      value: $(tasks.second-add.results.sum)-$(tasks.first-add.results.sum)
+---
+apiVersion: tekton.dev/v1beta1
+kind: PipelineRun
+metadata:
+  name: sum-three-pipeline-run
+spec:
+  pipelineRef:
+    name: sum-three-pipeline
+  params:
+    - name: first
+      value: "2"
+    - name: second
+      value: "10"
+    - name: third
+      value: "10"

go.mod

@@ -4,6 +4,7 @@ go 1.13
 
 require (
 	cloud.google.com/go v0.47.0 // indirect
+	cloud.google.com/go/storage v1.0.0
 	contrib.go.opencensus.io/exporter/stackdriver v0.12.8 // indirect
 	github.com/GoogleCloudPlatform/cloud-builders/gcs-fetcher v0.0.0-20191203181535-308b93ad1f39
 	github.com/cloudevents/sdk-go/v2 v2.0.0-preview8
@@ -40,6 +41,7 @@ require (
 	golang.org/x/time v0.0.0-20191024005414-555d28b269f0 // indirect
 	golang.org/x/tools v0.0.0-20200214144324-88be01311a71 // indirect
 	gomodules.xyz/jsonpatch/v2 v2.1.0 // indirect
+	google.golang.org/api v0.15.0
 	google.golang.org/appengine v1.6.5 // indirect
 	k8s.io/api v0.17.3
 	k8s.io/apiextensions-apiserver v0.17.3 // indirect

pkg/apis/pipeline/v1alpha1/pipeline_types.go

@@ -40,8 +40,14 @@ type PipelineSpec struct {
 	// provided by a PipelineRun.
 	// +optional
 	Workspaces []WorkspacePipelineDeclaration `json:"workspaces,omitempty"`
+	// Results are values that this pipeline can output once run
+	// +optional
+	Results []PipelineResult `json:"results,omitempty"`
 }
 
+// PipelineResult used to describe the results of a pipeline
+type PipelineResult = v1beta1.PipelineResult
+
 // Check that Pipeline may be validated and defaulted.
 // TaskKind defines the type of Task used by the pipeline.
 type TaskKind = v1beta1.TaskKind
@@ -164,9 +170,12 @@ func (pt PipelineTask) Deps() []string {
 	}
 	// Add any dependents from task results
 	for _, param := range pt.Params {
-		if resultRefs, err := v1beta1.NewResultRefs(param); err == nil {
-			for _, resultRef := range resultRefs {
-				deps = append(deps, resultRef.PipelineTask)
+		expressions, ok := v1beta1.GetVarSubstitutionExpressionsForParam(param)
+		if ok {
+			if resultRefs, err := v1beta1.NewResultRefs(expressions); err == nil {
+				for _, resultRef := range resultRefs {
+					deps = append(deps, resultRef.PipelineTask)
+				}
 			}
 		}
 	}

pkg/apis/pipeline/v1alpha1/pipeline_validation.go

@@ -140,8 +140,26 @@ func validateGraph(tasks []PipelineTask) error {
 func validateParamResults(tasks []PipelineTask) error {
 	for _, task := range tasks {
 		for _, param := range task.Params {
-			if v1beta1.LooksLikeContainsResultRefs(param) {
-				if _, err := v1beta1.NewResultRefs(param); err != nil {
+			expressions, ok := v1beta1.GetVarSubstitutionExpressionsForParam(param)
+			if ok {
+				if v1beta1.LooksLikeContainsResultRefs(expressions) {
+					if _, err := v1beta1.NewResultRefs(expressions); err != nil {
+						return err
+					}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// validatePipelineResults ensure that task result variables are properly configured
+func validatePipelineResults(results []PipelineResult) error {
+	for _, result := range results {
+		expressions, ok := v1beta1.GetVarSubstitutionExpressionsForPipelineResult(result)
+		if ok {
+			if v1beta1.LooksLikeContainsResultRefs(expressions) {
+				if _, err := v1beta1.NewResultRefs(expressions); err != nil {
 					return err
 				}
 			}
@@ -228,6 +246,11 @@ func (ps *PipelineSpec) Validate(ctx context.Context) *apis.FieldError {
 		return err
 	}
 
+	// Validate the pipeline's results
+	if err := validatePipelineResults(ps.Results); err != nil {
+		return apis.ErrInvalidValue(err.Error(), "spec.tasks.params.value")
+	}
+
 	return nil
 }