Implement output for pipeline describe

Closes: cloudfoundry#581, cloudfoundry#640

Signed-off-by: Chmouel Boudjnah <chmouel@redhat.com>

pkg/cmd/pipeline/describe.go

@@ -17,6 +17,7 @@ package pipeline
 import (
 	"fmt"
 	"io"
+	"os"
 	"sort"
 	"strings"
 	"text/tabwriter"
@@ -26,8 +27,11 @@ import (
 	"github.com/tektoncd/cli/pkg/cli"
 	"github.com/tektoncd/cli/pkg/formatted"
 	validate "github.com/tektoncd/cli/pkg/helper/validate"
+	"github.com/tektoncd/cli/pkg/printer"
 	"github.com/tektoncd/pipeline/pkg/apis/pipeline/v1alpha1"
+	"github.com/tektoncd/pipeline/pkg/client/clientset/versioned"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 	cliopts "k8s.io/cli-runtime/pkg/genericclioptions"
 )
 
@@ -101,6 +105,16 @@ func describeCommand(p cli.Params) *cobra.Command {
 				return err
 			}
 
+			output, err := cmd.LocalFlags().GetString("output")
+			if err != nil {
+				fmt.Fprint(os.Stderr, "Error: output option not set properly \n")
+				return err
+			}
+
+			if output != "" {
+				return describePipelineOutput(cmd.OutOrStdout(), p, f, args[0])
+			}
+
 			return printPipelineDescription(cmd.OutOrStdout(), p, args[0])
 		},
 	}
@@ -110,6 +124,37 @@ func describeCommand(p cli.Params) *cobra.Command {
 	return c
 }
 
+func describePipelineOutput(w io.Writer, p cli.Params, f *cliopts.PrintFlags, pname string) error {
+	cs, err := p.Clients()
+	if err != nil {
+		return err
+	}
+
+	pipeline, err := outputPipeline(cs.Tekton, p.Namespace(), pname)
+	if err != nil {
+		return err
+	}
+	return printer.PrintObject(w, pipeline, f)
+}
+
+func outputPipeline(cs versioned.Interface, ns, pname string) (*v1alpha1.Pipeline, error) {
+	c := cs.TektonV1alpha1().Pipelines(ns)
+
+	pipeline, err := c.Get(pname, metav1.GetOptions{})
+	if err != nil {
+		return nil, err
+	}
+
+	// NOTE: this is required for -o json|yaml to work properly since
+	// tektoncd go client fails to set these; probably a bug
+	pipeline.GetObjectKind().SetGroupVersionKind(
+		schema.GroupVersionKind{
+			Version: "tekton.dev/v1alpha1",
+			Kind:    "Pipeline",
+		})
+	return pipeline, nil
+}
+
 func printPipelineDescription(out io.Writer, p cli.Params, pname string) error {
 	cs, err := p.Clients()
 	if err != nil {

pkg/cmd/pipeline/describe_test.go

@@ -16,6 +16,7 @@ package pipeline
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 	"time"
 
@@ -331,3 +332,36 @@ func TestPipelinesDescribe_with_multiple_resource_param_task_run(t *testing.T) {
 	}
 	golden.Assert(t, got, fmt.Sprintf("%s.golden", t.Name()))
 }
+
+func TestPipelinesDescribe_custom_output(t *testing.T) {
+	clock := clockwork.NewFakeClock()
+	cs, _ := test.SeedTestData(t, pipelinetest.Data{
+		Pipelines: []*v1alpha1.Pipeline{
+			tb.Pipeline("pipeline", "ns",
+				tb.PipelineSpec(
+					tb.PipelineDeclaredResource("name", v1alpha1.PipelineResourceTypeGit),
+				),
+			),
+		},
+		Namespaces: []*corev1.Namespace{
+			{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "ns",
+				},
+			},
+		},
+	})
+
+	p := &test.Params{Tekton: cs.Pipeline, Clock: clock, Kube: cs.Kube}
+	pipeline := Command(p)
+
+	got, err := test.ExecuteCommand(pipeline, "desc", "-o", "name", "-n", "ns", "pipeline")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	got = strings.TrimSpace(got)
+	if got != "pipeline.tekton.dev/pipeline" {
+		t.Errorf("Result should be 'pipeline.tekton.dev/pipeline' != '%s'", got)
+	}
+}