Added --no-headers flag for resource listing

docs/cmd/kn_revision_list.md

@@ -34,6 +34,7 @@ kn revision list [name] [flags]
       --allow-missing-template-keys   If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats. (default true)
   -h, --help                          help for list
   -n, --namespace string              List the requested object(s) in given namespace.
+      --no-headers                    Remove column headers in default table output.
   -o, --output string                 Output format. One of: json|yaml|name|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-file.
   -s, --service string                Service name
       --template string               Template string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].

docs/cmd/kn_route_list.md

@@ -31,6 +31,7 @@ kn route list NAME [flags]
       --allow-missing-template-keys   If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats. (default true)
   -h, --help                          help for list
   -n, --namespace string              List the requested object(s) in given namespace.
+      --no-headers                    Remove column headers in default table output.
   -o, --output string                 Output format. One of: json|yaml|name|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-file.
       --template string               Template string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].
 ```

docs/cmd/kn_service_list.md

@@ -31,6 +31,7 @@ kn service list [name] [flags]
       --allow-missing-template-keys   If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats. (default true)
   -h, --help                          help for list
   -n, --namespace string              List the requested object(s) in given namespace.
+      --no-headers                    Remove column headers in default table output.
   -o, --output string                 Output format. One of: json|yaml|name|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-file.
       --template string               Template string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].
 ```

pkg/kn/commands/human_readable_flags.go

@@ -30,26 +30,28 @@ import (
 // Given the following flag values, a printer can be requested that knows
 // how to handle printing based on these values.
 type HumanPrintFlags struct {
+	NoHeaders bool
 	//TODO: Add more flags as required
 }
 
 // AllowedFormats returns more customized formating options
 func (f *HumanPrintFlags) AllowedFormats() []string {
 	// TODO: Add more formats eg: wide
-	return []string{""}
+	return []string{"no-headers"}
 }
 
 // ToPrinter receives returns a printer capable of
 // handling human-readable output.
 func (f *HumanPrintFlags) ToPrinter(getHandlerFunc func(h hprinters.PrintHandler)) (hprinters.ResourcePrinter, error) {
-	p := hprinters.NewTablePrinter(hprinters.PrintOptions{})
+	p := hprinters.NewTablePrinter(hprinters.PrintOptions{NoHeaders: f.NoHeaders})
 	getHandlerFunc(p)
 	return p, nil
 }
 
 // AddFlags receives a *cobra.Command reference and binds
 // flags related to human-readable printing to it
 func (f *HumanPrintFlags) AddFlags(c *cobra.Command) {
+	c.Flags().BoolVar(&f.NoHeaders, "no-headers", false, "Remove column headers in default table output.")
 	//TODO: Add more flags as required
 }
 

pkg/kn/commands/revision/revision_list_test.go

@@ -92,6 +92,23 @@ func TestRevisionListDefaultOutput(t *testing.T) {
 	assert.Check(t, util.ContainsAll(output[2], "bar-wxyz", "bar"))
 }
 
+func TestRevisionListDefaultOutputNoHeaders(t *testing.T) {
+	revision1 := createMockRevisionWithParams("foo-abcd", "foo")
+	revision2 := createMockRevisionWithParams("bar-wxyz", "bar")
+	RevisionList := &v1alpha1.RevisionList{Items: []v1alpha1.Revision{*revision1, *revision2}}
+	action, output, err := fakeRevisionList([]string{"revision", "list", "--no-headers"}, RevisionList)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if action == nil {
+		t.Errorf("No action")
+	} else if !action.Matches("list", "revisions") {
+		t.Errorf("Bad action %v", action)
+	}
+	assert.Check(t, util.ContainsAll(output[0], "foo-abcd", "foo"))
+	assert.Check(t, util.ContainsAll(output[1], "bar-wxyz", "bar"))
+}
+
 func TestRevisionListForService(t *testing.T) {
 	revision1 := createMockRevisionWithParams("foo-abcd", "svc1")
 	revision2 := createMockRevisionWithParams("bar-wxyz", "svc1")

pkg/kn/commands/route/list_test.go

@@ -77,6 +77,23 @@ func TestRouteListDefaultOutput(t *testing.T) {
 	assert.Check(t, util.ContainsAll(output[2], "bar", "100% -> bar-98765"))
 }
 
+func TestRouteListDefaultOutputNoHeaders(t *testing.T) {
+	route1 := createMockRouteSingleTarget("foo", "foo-01234", 100)
+	route2 := createMockRouteSingleTarget("bar", "bar-98765", 100)
+	routeList := &v1alpha1.RouteList{Items: []v1alpha1.Route{*route1, *route2}}
+	action, output, err := fakeRouteList([]string{"route", "list", "--no-headers"}, routeList)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if action == nil {
+		t.Errorf("No action")
+	} else if !action.Matches("list", "routes") {
+		t.Errorf("Bad action %v", action)
+	}
+	assert.Check(t, util.ContainsAll(output[0], "foo", "100% -> foo-01234"))
+	assert.Check(t, util.ContainsAll(output[1], "bar", "100% -> bar-98765"))
+}
+
 func TestRouteListWithTwoTargetsOutput(t *testing.T) {
 	route := createMockRouteTwoTarget("foo", "foo-01234", "foo-98765", 20, 80)
 	routeList := &v1alpha1.RouteList{Items: []v1alpha1.Route{*route}}

pkg/kn/commands/service/service_list_test.go

@@ -93,6 +93,23 @@ func TestServiceListDefaultOutput(t *testing.T) {
 	assert.Check(t, util.ContainsAll(output[2], "bar", "bar.default.example.com", "2"))
 }
 
+func TestServiceListDefaultOutputNoHeaders(t *testing.T) {
+	service1 := createMockServiceWithParams("foo", "http://foo.default.example.com", 1)
+	service2 := createMockServiceWithParams("bar", "http://bar.default.example.com", 2)
+	serviceList := &v1alpha1.ServiceList{Items: []v1alpha1.Service{*service1, *service2}}
+	action, output, err := fakeServiceList([]string{"service", "list", "--no-headers"}, serviceList)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if action == nil {
+		t.Errorf("No action")
+	} else if !action.Matches("list", "services") {
+		t.Errorf("Bad action %v", action)
+	}
+	assert.Check(t, util.ContainsAll(output[0], "foo", "foo.default.example.com", "1"))
+	assert.Check(t, util.ContainsAll(output[1], "bar", "bar.default.example.com", "2"))
+}
+
 func TestServiceGetOneOutput(t *testing.T) {
 	service := createMockServiceWithParams("foo", "foo.default.example.com", 1)
 	serviceList := &v1alpha1.ServiceList{Items: []v1alpha1.Service{*service}}

pkg/printers/interface.go

@@ -38,5 +38,6 @@ func (fn ResourcePrinterFunc) PrintObj(obj runtime.Object, w io.Writer) error {
 
 // PrintOptions for different table printing options
 type PrintOptions struct {
+	NoHeaders bool
 	//TODO: Add options for eg: with-kind, server-printing, wide etc
 }

pkg/printers/tableprinter.go

@@ -73,12 +73,13 @@ func printRowsForHandlerEntry(output io.Writer, handler *handlerEntry, obj runti
 	if !results[1].IsNil() {
 		return results[1].Interface().(error)
 	}
-
-	var headers []string
-	for _, column := range handler.columnDefinitions {
-		headers = append(headers, strings.ToUpper(column.Name))
+	if !options.NoHeaders {
+		var headers []string
+		for _, column := range handler.columnDefinitions {
+			headers = append(headers, strings.ToUpper(column.Name))
+		}
+		printHeader(headers, output)
 	}
-	printHeader(headers, output)
 
 	if results[1].IsNil() {
 		rows := results[0].Interface().([]metav1beta1.TableRow)