Fix error when output is set to name

[daisy-ycguo]

Describe

Fix the error when calling kn service list -o name. Because the default name printer only supports unstructured.UnstructuredList, we have to convert servingv1.ServiceList to unstructured.UnstructuredList when output flag is set.

Changes

• Convert servingv1.ServiceList to unstructured.UnstructuredList when output flag is set in kn service list -o name

Reference

Fixes #754

[navidshaikh]

see if you can reuse https://github.com/knative/pkg/blob/master/apis/duck/unstructured.go#L32

[daisy-ycguo]

Thanks for the information.
I checked pkg/apis/duck, and noticed it only accepts an interface duck.OneOfOurs. Unfortunately, neither servingv1.ServiceList nor servingv1.Service , runtime.Object cannot satisfy that interface. So I cannot leverage it.

[maximilien]

See feedback

[maximilien]

s/unstructedList/unstructuredList/

[daisy-ycguo]

changed in the new version.

[maximilien]

Where is the unit test for this ToUnstructuredList exported function?

[daisy-ycguo]

see TestToUnstructuredList in pkg/util/unstructured_test.go

[navidshaikh]

We can solve this and also improve the list printing for all command groups.
If we pull the following check earlier in pkg/kn/commands/flags/listprint.go

			if serviceListFlags.GenericPrintFlags.OutputFlagSpecified() {
				unstructedList, err := util.ToUnstructuredList(serviceList)

and add another method Print to ListPrintFlags taking care of finding correct printer and above check+conversion,
we solve this for other list commands too.
I tried doing ^^ on your PR and replaced the print call for revision list (can be done in similar way for route.. etc)

➜  client git:(f5a4863b) ✗ git --no-pager diff .
diff --git a/pkg/kn/commands/flags/listprint.go b/pkg/kn/commands/flags/listprint.go
index a19cca49..2ec1c81d 100644
--- a/pkg/kn/commands/flags/listprint.go
+++ b/pkg/kn/commands/flags/listprint.go
@@ -15,11 +15,15 @@
 package flags
 
 import (
+	"io"
+
 	"github.com/spf13/cobra"
+	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 
 	"knative.dev/client/pkg/kn/commands"
 	hprinters "knative.dev/client/pkg/printers"
+	"knative.dev/client/pkg/util"
 )
 
 // ListFlags composes common printer flag structs
@@ -56,6 +60,23 @@ func (f *ListPrintFlags) ToPrinter() (hprinters.ResourcePrinter, error) {
 	return p, nil
 }
 
+func (f *ListPrintFlags) Print(obj runtime.Object, w io.Writer) error {
+	printer, err := f.ToPrinter()
+	if err != nil {
+		return err
+	}
+
+	if f.GenericPrintFlags.OutputFlagSpecified() {
+		unstructedList, err := util.ToUnstructuredList(obj)
+		if err != nil {
+			return err
+		}
+		return printer.PrintObj(unstructedList, w)
+	}
+
+	return printer.PrintObj(obj, w)
+}
+
 // AddFlags receives a *cobra.Command reference and binds
 // flags related to humanreadable and template printing.
 func (f *ListPrintFlags) AddFlags(cmd *cobra.Command) {
diff --git a/pkg/kn/commands/revision/list.go b/pkg/kn/commands/revision/list.go
index 88f733f5..3821d76e 100644
--- a/pkg/kn/commands/revision/list.go
+++ b/pkg/kn/commands/revision/list.go
@@ -102,13 +102,7 @@ func NewRevisionListCommand(p *commands.KnParams) *cobra.Command {
 			// Sort revisions by namespace, service, generation (in this order)
 			sortRevisions(revisionList)
 
-			// Print out infos via printer framework
-			printer, err := revisionListFlags.ToPrinter()
-			if err != nil {
-				return err
-			}
-
-			return printer.PrintObj(revisionList, cmd.OutOrStdout())
+			return revisionListFlags.Print(revisionList, cmd.OutOrStdout())
 		},
 	}
 	commands.AddNamespaceFlags(revisionListCommand.Flags(), true)
diff --git a/pkg/kn/commands/service/list.go b/pkg/kn/commands/service/list.go
index 974db353..10a3308c 100644
--- a/pkg/kn/commands/service/list.go
+++ b/pkg/kn/commands/service/list.go
@@ -24,7 +24,6 @@ import (
 	"knative.dev/client/pkg/kn/commands"
 	"knative.dev/client/pkg/kn/commands/flags"
 	clientservingv1 "knative.dev/client/pkg/serving/v1"
-	"knative.dev/client/pkg/util"
 )
 
 // NewServiceListCommand represents 'kn service list' command
@@ -66,11 +65,6 @@ func NewServiceListCommand(p *commands.KnParams) *cobra.Command {
 				serviceListFlags.EnsureWithNamespace()
 			}
 
-			printer, err := serviceListFlags.ToPrinter()
-			if err != nil {
-				return err
-			}
-
 			// Sort serviceList by namespace and name (in this order)
 			sort.SliceStable(serviceList.Items, func(i, j int) bool {
 				a := serviceList.Items[i]
@@ -82,15 +76,7 @@ func NewServiceListCommand(p *commands.KnParams) *cobra.Command {
 				return a.ObjectMeta.Name < b.ObjectMeta.Name
 			})
 
-			if serviceListFlags.GenericPrintFlags.OutputFlagSpecified() {
-				unstructedList, err := util.ToUnstructuredList(serviceList)
-				if err != nil {
-					return err
-				}
-				return printer.PrintObj(unstructedList, cmd.OutOrStdout())
-			}
-
-			return printer.PrintObj(serviceList, cmd.OutOrStdout())
+			return serviceListFlags.Print(serviceList, cmd.OutOrStdout())
 		},
 	}
 	commands.AddNamespaceFlags(serviceListCommand.Flags(), true)

here is the output:

➜  client git:(f5a4863b) ✗ ./kn revision list -oname
revision.serving.knative.dev/svc-tgzvv-1
➜  client git:(f5a4863b) ✗ ./kn service list -oname 
service.serving.knative.dev/svc

[navidshaikh]

/retest

[navidshaikh]

@daisy-ycguo needs rebase and changes in e2e as e2e refactor PR is in now

test/e2e/basic_workflow_test.go:52:19: not enough arguments in call to serviceListOutput
	have (*test.KnRunResultCollector, string)
	want (*test.KnRunResultCollector, *test.KnRunResultCollector, string)

[knative-metrics-robot]

The following is the coverage report on the affected files.
Say /test pull-knative-client-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/kn/commands/flags/listprint.go	62.5%	56.0%	-6.5
pkg/kn/commands/service/list.go	89.5%	93.8%	4.3
pkg/util/unstructured.go	Do not exist	78.3%

[daisy-ycguo]

@navidshaikh This PR is ready for review.

[navidshaikh]

/lgtm
/approve

Thanks Daisy!

[navidshaikh]

Suggested change

[navidshaikh]

Suggested change

	// Copyright © 2019 The Knative Authors
	// Copyright © 2020 The Knative Authors

[navidshaikh]

does it require to set creationTimeStamp field ?

[knative-prow-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: daisy-ycguo, maximilien, navidshaikh

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