apiextensions-apiserver: add columns to CRD spec

staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/fuzzer/fuzzer.go

@@ -23,9 +23,12 @@ import (
 	"github.com/google/gofuzz"
 
 	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	runtimeserializer "k8s.io/apimachinery/pkg/runtime/serializer"
 )
 
+var swaggerMetadataDescriptions = metav1.ObjectMeta{}.SwaggerDoc()
+
 // Funcs returns the fuzzer functions for the apiextensions apis.
 func Funcs(codecs runtimeserializer.CodecFactory) []interface{} {
 	return []interface{}{
@@ -53,6 +56,11 @@ func Funcs(codecs runtimeserializer.CodecFactory) []interface{} {
 			} else if len(obj.Versions) != 0 {
 				obj.Version = obj.Versions[0].Name
 			}
+			if len(obj.AdditionalPrinterColumns) == 0 {
+				obj.AdditionalPrinterColumns = []apiextensions.CustomResourceColumnDefinition{
+					{Name: "Age", Type: "date", Description: swaggerMetadataDescriptions["creationTimestamp"], JSONPath: ".metadata.creationTimestamp"},
+				}
+			}
 		},
 		func(obj *apiextensions.CustomResourceDefinition, c fuzz.Continue) {
 			c.FuzzNoCustom(obj)

staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/types.go

@@ -49,6 +49,8 @@ type CustomResourceDefinitionSpec struct {
 	// major version, then minor version. An example sorted list of versions:
 	// v10, v2, v1, v11beta2, v10beta3, v3beta1, v12alpha1, v11alpha2, foo1, foo10.
 	Versions []CustomResourceDefinitionVersion
+	// AdditionalPrinterColumns are additional columns shown e.g. in kubectl next to the name. Defaults to a created-at column.
+	AdditionalPrinterColumns []CustomResourceColumnDefinition
 }
 
 type CustomResourceDefinitionVersion struct {
@@ -61,6 +63,28 @@ type CustomResourceDefinitionVersion struct {
 	Storage bool
 }
 
+// CustomResourceColumnDefinition specifies a column for server side printing.
+type CustomResourceColumnDefinition struct {
+	// name is a human readable name for the column.
+	Name string
+	// type is an OpenAPI type definition for this column.
+	// See https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types for more.
+	Type string
+	// format is an optional OpenAPI type definition for this column. The 'name' format is applied
+	// to the primary identifier column to assist in clients identifying column is the resource name.
+	// See https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types for more.
+	Format string
+	// description is a human readable description of this column.
+	Description string
+	// priority is an integer defining the relative importance of this column compared to others. Lower
+	// numbers are considered higher priority. Columns that may be omitted in limited space scenarios
+	// should be given a higher priority.
+	Priority int32
+
+	// JSONPath is a simple JSON path, i.e. without array notation.
+	JSONPath string
+}
+
 // CustomResourceDefinitionNames indicates the names to serve this CustomResourceDefinition
 type CustomResourceDefinitionNames struct {
 	// Plural is the plural name of the resource to serve.  It must match the name of the CustomResourceDefinition-registration

staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1/defaults.go

@@ -19,9 +19,12 @@ package v1beta1
 import (
 	"strings"
 
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
+var swaggerMetadataDescriptions = metav1.ObjectMeta{}.SwaggerDoc()
+
 func addDefaultingFuncs(scheme *runtime.Scheme) error {
 	scheme.AddTypeDefaultingFunc(&CustomResourceDefinition{}, func(obj interface{}) { SetDefaults_CustomResourceDefinition(obj.(*CustomResourceDefinition)) })
 	// TODO figure out why I can't seem to get my defaulter generated
@@ -63,4 +66,9 @@ func SetDefaults_CustomResourceDefinitionSpec(obj *CustomResourceDefinitionSpec)
 	if len(obj.Version) == 0 && len(obj.Versions) != 0 {
 		obj.Version = obj.Versions[0].Name
 	}
+	if len(obj.AdditionalPrinterColumns) == 0 {
+		obj.AdditionalPrinterColumns = []CustomResourceColumnDefinition{
+			{Name: "Age", Type: "date", Description: swaggerMetadataDescriptions["creationTimestamp"], JSONPath: ".metadata.creationTimestamp"},
+		}
+	}
 }

staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1/types.go

@@ -52,6 +52,8 @@ type CustomResourceDefinitionSpec struct {
 	// major version, then minor version. An example sorted list of versions:
 	// v10, v2, v1, v11beta2, v10beta3, v3beta1, v12alpha1, v11alpha2, foo1, foo10.
 	Versions []CustomResourceDefinitionVersion `json:"versions,omitempty" protobuf:"bytes,7,rep,name=versions"`
+	// AdditionalPrinterColumns are additional columns shown e.g. in kubectl next to the name. Defaults to a created-at column.
+	AdditionalPrinterColumns []CustomResourceColumnDefinition `json:"additionalPrinterColumns,omitempty" protobuf:"bytes,8,rep,name=additionalPrinterColumns"`
 }
 
 type CustomResourceDefinitionVersion struct {
@@ -64,6 +66,28 @@ type CustomResourceDefinitionVersion struct {
 	Storage bool `json:"storage" protobuf:"varint,3,opt,name=storage"`
 }
 
+// CustomResourceColumnDefinition specifies a column for server side printing.
+type CustomResourceColumnDefinition struct {
+	// name is a human readable name for the column.
+	Name string `json:"name" protobuf:"bytes,1,opt,name=name"`
+	// type is an OpenAPI type definition for this column.
+	// See https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types for more.
+	Type string `json:"type" protobuf:"bytes,2,opt,name=type"`
+	// format is an optional OpenAPI type definition for this column. The 'name' format is applied
+	// to the primary identifier column to assist in clients identifying column is the resource name.
+	// See https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types for more.
+	Format string `json:"format,omitempty" protobuf:"bytes,3,opt,name=format"`
+	// description is a human readable description of this column.
+	Description string `json:"description,omitempty" protobuf:"bytes,4,opt,name=description"`
+	// priority is an integer defining the relative importance of this column compared to others. Lower
+	// numbers are considered higher priority. Columns that may be omitted in limited space scenarios
+	// should be given a higher priority.
+	Priority int32 `json:"priority,omitempty" protobuf:"bytes,5,opt,name=priority"`
+
+	// JSONPath is a simple JSON path, i.e. with array notation.
+	JSONPath string `json:"JSONPath" protobuf:"bytes,6,opt,name=JSONPath"`
+}
+
 // CustomResourceDefinitionNames indicates the names to serve this CustomResourceDefinition
 type CustomResourceDefinitionNames struct {
 	// Plural is the plural name of the resource to serve.  It must match the name of the CustomResourceDefinition-registration

staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation.go

@@ -22,6 +22,7 @@ import (
 	"strings"
 
 	genericvalidation "k8s.io/apimachinery/pkg/api/validation"
+	"k8s.io/apimachinery/pkg/util/sets"
 	validationutil "k8s.io/apimachinery/pkg/util/validation"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
@@ -31,6 +32,11 @@ import (
 	apiextensionsfeatures "k8s.io/apiextensions-apiserver/pkg/features"
 )
 
+var (
+	printerColumnDatatypes                = sets.NewString("integer", "number", "string", "boolean", "date")
+	customResourceColumnDefinitionFormats = sets.NewString("int32", "int64", "float", "double", "byte", "date", "date-time", "password")
+)
+
 // ValidateCustomResourceDefinition statically validates
 func ValidateCustomResourceDefinition(obj *apiextensions.CustomResourceDefinition) field.ErrorList {
 	nameValidationFn := func(name string, prefix bool) []string {
@@ -175,6 +181,12 @@ func ValidateCustomResourceDefinitionSpec(spec *apiextensions.CustomResourceDefi
 		allErrs = append(allErrs, field.Forbidden(fldPath.Child("subresources"), "disabled by feature-gate CustomResourceSubresources"))
 	}
 
+	for i := range spec.AdditionalPrinterColumns {
+		if errs := ValidateCustomResourceColumnDefinition(&spec.AdditionalPrinterColumns[i], fldPath.Child("columns").Index(i)); len(errs) > 0 {
+			allErrs = append(allErrs, errs...)
+		}
+	}
+
 	return allErrs
 }
 
@@ -238,6 +250,33 @@ func ValidateCustomResourceDefinitionNames(names *apiextensions.CustomResourceDe
 	return allErrs
 }
 
+// ValidateCustomResourceColumnDefinition statically validates a printer column.
+func ValidateCustomResourceColumnDefinition(col *apiextensions.CustomResourceColumnDefinition, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+
+	if len(col.Name) == 0 {
+		allErrs = append(allErrs, field.Required(fldPath.Child("header"), ""))
+	}
+
+	if len(col.Type) == 0 {
+		allErrs = append(allErrs, field.Required(fldPath.Child("type"), fmt.Sprintf("must be one of %s", strings.Join(printerColumnDatatypes.List(), ","))))
+	} else if !printerColumnDatatypes.Has(col.Type) {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("type"), col.Type, fmt.Sprintf("must be one of %s", strings.Join(printerColumnDatatypes.List(), ","))))
+	}
+
+	if len(col.Format) > 0 && !customResourceColumnDefinitionFormats.Has(col.Format) {
+		allErrs = append(allErrs, field.Invalid(fldPath.Child("format"), col.Format, fmt.Sprintf("must be one of %s", strings.Join(customResourceColumnDefinitionFormats.List(), ","))))
+	}
+
+	if len(col.JSONPath) == 0 {
+		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
+	} else if errs := validateSimpleJSONPath(col.JSONPath, fldPath.Child("path")); len(errs) > 0 {
+		allErrs = append(allErrs, errs...)
+	}
+
+	return allErrs
+}
+
 // specStandardValidator applies validations for different OpenAPI specification versions.
 type specStandardValidator interface {
 	validate(spec *apiextensions.JSONSchemaProps, fldPath *field.Path) field.ErrorList

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/customresource_handler.go

@@ -370,6 +370,8 @@ func (r *crdHandler) GetCustomResourceListerCollectionDeleter(crd *apiextensions
 	return info.storages[info.storageVersion].CustomResource, nil
 }
 
+var swaggerMetadataDescriptions = metav1.ObjectMeta{}.SwaggerDoc()
+
 func (r *crdHandler) getOrCreateServingInfoFor(crd *apiextensions.CustomResourceDefinition) (*crdInfo, error) {
 	storageMap := r.customStorage.Load().(crdStorageMap)
 	if ret, ok := storageMap[crd.UID]; ok {
@@ -439,8 +441,7 @@ func (r *crdHandler) getOrCreateServingInfoFor(crd *apiextensions.CustomResource
 			scaleSpec = crd.Spec.Subresources.Scale
 		}
 
-		// TODO: identify how to pass printer specification from the CRD
+		table, err := tableconvertor.New(crd.Spec.AdditionalPrinterColumns)
-		table, err := tableconvertor.New(nil)
 		if err != nil {
 			glog.V(2).Infof("The CRD for %v has an invalid printer specification, falling back to default printing: %v", kind, err)
 		}

staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd_test.go

@@ -21,12 +21,15 @@ import (
 	"reflect"
 	"strings"
 	"testing"
+	"time"
 
 	autoscalingv1 "k8s.io/api/autoscaling/v1"
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/errors"
+	metainternal "k8s.io/apimachinery/pkg/apis/meta/internalversion"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	metav1beta1 "k8s.io/apimachinery/pkg/apis/meta/v1beta1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/util/diff"
@@ -72,8 +75,19 @@ func newStorage(t *testing.T) (customresource.CustomResourceStorage, *etcdtestin
 
 	status := &apiextensions.CustomResourceSubresourceStatus{}
 
-	// TODO: identify how to pass printer specification from the CRD
+	headers := []apiextensions.CustomResourceColumnDefinition{
-	table, _ := tableconvertor.New(nil)
+		{Name: "Age", Type: "date", JSONPath: ".metadata.creationTimestamp"},
+		{Name: "Replicas", Type: "integer", JSONPath: ".spec.replicas"},
+		{Name: "Missing", Type: "string", JSONPath: ".spec.missing"},
+		{Name: "Invalid", Type: "integer", JSONPath: ".spec.string"},
+		{Name: "String", Type: "string", JSONPath: ".spec.string"},
+		{Name: "StringFloat64", Type: "string", JSONPath: ".spec.float64"},
+		{Name: "StringInt64", Type: "string", JSONPath: ".spec.replicas"},
+		{Name: "StringBool", Type: "string", JSONPath: ".spec.bool"},
+		{Name: "Float64", Type: "number", JSONPath: ".spec.float64"},
+		{Name: "Bool", Type: "boolean", JSONPath: ".spec.bool"},
+	}
+	table, _ := tableconvertor.New(headers)
 
 	storage := customresource.NewStorage(
 		schema.GroupResource{Group: "mygroup.example.com", Resource: "noxus"},
@@ -114,9 +128,16 @@ func validNewCustomResource() *unstructured.Unstructured {
 			"metadata": map[string]interface{}{
 				"namespace":         "default",
 				"name":              "foo",
+				"creationTimestamp": time.Now().Add(-time.Hour*12 - 30*time.Minute).UTC().Format(time.RFC3339),
 			},
 			"spec": map[string]interface{}{
 				"replicas":         int64(7),
+				"string":           "string",
+				"float64":          float64(3.1415926),
+				"bool":             true,
+				"stringList":       []interface{}{"foo", "bar"},
+				"mixedList":        []interface{}{"foo", int64(42)},
+				"nonPrimitiveList": []interface{}{"foo", []interface{}{int64(1), int64(2)}},
 			},
 		},
 	}
@@ -225,6 +246,77 @@ func TestCategories(t *testing.T) {
 	}
 }
 
+func TestColumns(t *testing.T) {
+	storage, server := newStorage(t)
+	defer server.Terminate(t)
+	defer storage.CustomResource.Store.DestroyFunc()
+
+	ctx := genericapirequest.WithNamespace(genericapirequest.NewContext(), metav1.NamespaceDefault)
+	key := "/noxus/" + metav1.NamespaceDefault + "/foo"
+	validCustomResource := validNewCustomResource()
+	if err := storage.CustomResource.Storage.Create(ctx, key, validCustomResource, nil, 0); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	gottenList, err := storage.CustomResource.List(ctx, &metainternal.ListOptions{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	tbl, err := storage.CustomResource.ConvertToTable(ctx, gottenList, &metav1beta1.TableOptions{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	expectedColumns := []struct {
+		Name, Type string
+	}{
+		{"Name", "string"},
+		{"Age", "date"},
+		{"Replicas", "integer"},
+		{"Missing", "string"},
+		{"Invalid", "integer"},
+		{"String", "string"},
+		{"StringFloat64", "string"},
+		{"StringInt64", "string"},
+		{"StringBool", "string"},
+		{"Float64", "number"},
+		{"Bool", "boolean"},
+	}
+	if len(tbl.ColumnDefinitions) != len(expectedColumns) {
+		t.Fatalf("got %d columns, expected %d. Got: %+v", len(tbl.ColumnDefinitions), len(expectedColumns), tbl.ColumnDefinitions)
+	}
+	for i, d := range tbl.ColumnDefinitions {
+		if d.Name != expectedColumns[i].Name {
+			t.Errorf("got column %d name %q, expected %q", i, d.Name, expectedColumns[i].Name)
+		}
+		if d.Type != expectedColumns[i].Type {
+			t.Errorf("got column %d type %q, expected %q", i, d.Type, expectedColumns[i].Type)
+		}
+	}
+
+	expectedRows := [][]interface{}{
+		{
+			"foo",
+			"12h",
+			int64(7),
+			nil,
+			nil,
+			"string",
+			"3.1415926",
+			"7",
+			"true",
+			float64(3.1415926),
+			true,
+		},
+	}
+	for i, r := range tbl.Rows {
+		if !reflect.DeepEqual(r.Cells, expectedRows[i]) {
+			t.Errorf("got row %d with cells %#v, expected %#v", i, r.Cells, expectedRows[i])
+		}
+	}
+}
+
 func TestStatusUpdate(t *testing.T) {
 	storage, server := newStorage(t)
 	defer server.Terminate(t)

staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/tableconvertor/tableconvertor.go

@@ -19,11 +19,11 @@ package tableconvertor
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
-	"strings"
+	"reflect"
-
-	"github.com/go-openapi/spec"
 
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metatable "k8s.io/apimachinery/pkg/api/meta/table"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -33,56 +33,46 @@ import (
 	"k8s.io/client-go/util/jsonpath"
 )
 
-const printColumnsKey = "x-kubernetes-print-columns"
-
 var swaggerMetadataDescriptions = metav1.ObjectMeta{}.SwaggerDoc()
 
-// New creates a new table convertor for the provided OpenAPI schema. If the printer definition cannot be parsed,
+// New creates a new table convertor for the provided CRD column definition. If the printer definition cannot be parsed,
 // error will be returned along with a default table convertor.
-func New(extensions spec.Extensions) (rest.TableConvertor, error) {
+func New(crdColumns []apiextensions.CustomResourceColumnDefinition) (rest.TableConvertor, error) {
 	headers := []metav1beta1.TableColumnDefinition{
 		{Name: "Name", Type: "string", Format: "name", Description: swaggerMetadataDescriptions["name"]},
-		{Name: "Age", Type: "date", Description: swaggerMetadataDescriptions["creationTimestamp"]},
 	}
 	c := &convertor{
 		headers: headers,
 	}
-	format, ok := extensions.GetString(printColumnsKey)
+
-	if !ok {
+	for _, col := range crdColumns {
-		return c, nil
+		path := jsonpath.New(col.Name)
-	}
+		if err := path.Parse(fmt.Sprintf("{%s}", col.JSONPath)); err != nil {
-	// "x-kubernetes-print-columns": "custom-columns=NAME:.metadata.name,RSRC:.metadata.resourceVersion"
+			return c, fmt.Errorf("unrecognized column definition %q", col.JSONPath)
-	parts := strings.SplitN(format, "=", 2)
-	if len(parts) != 2 || parts[0] != "custom-columns" {
-		return c, fmt.Errorf("unrecognized column definition in 'x-kubernetes-print-columns', only support 'custom-columns=NAME=JSONPATH[,NAME=JSONPATH]'")
-	}
-	columnSpecs := strings.Split(parts[1], ",")
-	var columns []*jsonpath.JSONPath
-	for _, spec := range columnSpecs {
-		parts := strings.SplitN(spec, ":", 2)
-		if len(parts) != 2 || len(parts[0]) == 0 || len(parts[1]) == 0 {
-			return c, fmt.Errorf("unrecognized column definition in 'x-kubernetes-print-columns', must specify NAME=JSONPATH: %s", spec)
-		}
-		path := jsonpath.New(parts[0])
-		if err := path.Parse(parts[1]); err != nil {
-			return c, fmt.Errorf("unrecognized column definition in 'x-kubernetes-print-columns': %v", spec)
 		}
 		path.AllowMissingKeys(true)
-		columns = append(columns, path)
+
-		headers = append(headers, metav1beta1.TableColumnDefinition{
+		desc := fmt.Sprintf("Custom resource definition column (in JSONPath format): %s", col.JSONPath)
-			Name:        parts[0],
+		if len(col.Description) > 0 {
-			Type:        "string",
+			desc = col.Description
-			Description: fmt.Sprintf("Custom resource definition column from OpenAPI (in JSONPath format): %s", parts[1]),
+		}
+
+		c.additionalColumns = append(c.additionalColumns, path)
+		c.headers = append(c.headers, metav1beta1.TableColumnDefinition{
+			Name:        col.Name,
+			Type:        col.Type,
+			Format:      col.Format,
+			Description: desc,
+			Priority:    col.Priority,
 		})
 	}
-	c.columns = columns
+
-	c.headers = headers
 	return c, nil
 }
 
 type convertor struct {
 	headers           []metav1beta1.TableColumnDefinition
-	columns []*jsonpath.JSONPath
+	additionalColumns []*jsonpath.JSONPath
 }
 
 func (c *convertor) ConvertToTable(ctx context.Context, obj runtime.Object, tableOptions runtime.Object) (*metav1beta1.Table, error) {
@@ -103,18 +93,80 @@ func (c *convertor) ConvertToTable(ctx context.Context, obj runtime.Object, tabl
 	var err error
 	buf := &bytes.Buffer{}
 	table.Rows, err = metatable.MetaToTableRow(obj, func(obj runtime.Object, m metav1.Object, name, age string) ([]interface{}, error) {
-		cells := make([]interface{}, 2, 2+len(c.columns))
+		cells := make([]interface{}, 1, 1+len(c.additionalColumns))
 		cells[0] = name
-		cells[1] = age
+		customHeaders := c.headers[1:]
-		for _, column := range c.columns {
+		for i, column := range c.additionalColumns {
-			if err := column.Execute(buf, obj); err != nil {
+			results, err := column.FindResults(obj.(runtime.Unstructured).UnstructuredContent())
+			if err != nil || len(results) == 0 || len(results[0]) == 0 {
 				cells = append(cells, nil)
 				continue
 			}
+
+			// as we only support simple JSON path, we can assume to have only one result (or none, filtered out above)
+			value := results[0][0].Interface()
+			if customHeaders[i].Type == "string" {
+				if err := column.PrintResults(buf, []reflect.Value{reflect.ValueOf(value)}); err == nil {
 					cells = append(cells, buf.String())
 					buf.Reset()
+				} else {
+					cells = append(cells, nil)
+				}
+			} else {
+				cells = append(cells, cellForJSONValue(customHeaders[i].Type, value))
+			}
 		}
 		return cells, nil
 	})
 	return table, err
 }
+
+func cellForJSONValue(headerType string, value interface{}) interface{} {
+	if value == nil {
+		return nil
+	}
+
+	switch headerType {
+	case "integer":
+		switch typed := value.(type) {
+		case int64:
+			return typed
+		case float64:
+			return int64(typed)
+		case json.Number:
+			if i64, err := typed.Int64(); err == nil {
+				return i64
+			}
+		}
+	case "number":
+		switch typed := value.(type) {
+		case int64:
+			return float64(typed)
+		case float64:
+			return typed
+		case json.Number:
+			if f, err := typed.Float64(); err == nil {
+				return f
+			}
+		}
+	case "boolean":
+		if b, ok := value.(bool); ok {
+			return b
+		}
+	case "string":
+		if s, ok := value.(string); ok {
+			return s
+		}
+	case "date":
+		if typed, ok := value.(string); ok {
+			var timestamp metav1.Time
+			err := timestamp.UnmarshalQueryParameter(typed)
+			if err != nil {
+				return "<invalid>"
+			}
+			return metatable.ConvertToHumanReadableDateType(timestamp)
+		}
+	}
+
+	return nil
+}

staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/tableconvertor/tableconvertor_test.go

@@ -0,0 +1,68 @@
+/*
+Copyright 2018 The Kubernetes 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 tableconvertor
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+	"time"
+)
+
+func Test_cellForJSONValue(t *testing.T) {
+	tests := []struct {
+		headerType string
+		value      interface{}
+		want       interface{}
+	}{
+		{"integer", int64(42), int64(42)},
+		{"integer", float64(3.14), int64(3)},
+		{"integer", true, nil},
+		{"integer", "foo", nil},
+
+		{"number", int64(42), float64(42)},
+		{"number", float64(3.14), float64(3.14)},
+		{"number", true, nil},
+		{"number", "foo", nil},
+
+		{"boolean", int64(42), nil},
+		{"boolean", float64(3.14), nil},
+		{"boolean", true, true},
+		{"boolean", "foo", nil},
+
+		{"string", int64(42), nil},
+		{"string", float64(3.14), nil},
+		{"string", true, nil},
+		{"string", "foo", "foo"},
+
+		{"date", int64(42), nil},
+		{"date", float64(3.14), nil},
+		{"date", true, nil},
+		{"date", time.Now().Add(-time.Hour*12 - 30*time.Minute).UTC().Format(time.RFC3339), "12h"},
+		{"date", time.Now().Add(+time.Hour*12 + 30*time.Minute).UTC().Format(time.RFC3339), "<invalid>"},
+		{"date", "", "<unknown>"},
+
+		{"unknown", "foo", nil},
+	}
+	for _, tt := range tests {
+		t.Run(fmt.Sprintf("%#v of type %s", tt.value, tt.headerType), func(t *testing.T) {
+			if got := cellForJSONValue(tt.headerType, tt.value); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("cellForJSONValue() = %#v, want %#v", got, tt.want)
+			}
+		})
+	}
+}

staging/src/k8s.io/apiextensions-apiserver/test/integration/table_test.go

@@ -0,0 +1,185 @@
+/*
+Copyright 2017 The Kubernetes 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 integration
+
+import (
+	"fmt"
+	"testing"
+
+	"k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	metav1beta1 "k8s.io/apimachinery/pkg/apis/meta/v1beta1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+	"k8s.io/client-go/dynamic"
+	"k8s.io/client-go/rest"
+
+	apiextensionsv1beta1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+	"k8s.io/apiextensions-apiserver/test/integration/testserver"
+)
+
+func newTableCRD() *apiextensionsv1beta1.CustomResourceDefinition {
+	return &apiextensionsv1beta1.CustomResourceDefinition{
+		ObjectMeta: metav1.ObjectMeta{Name: "tables.mygroup.example.com"},
+		Spec: apiextensionsv1beta1.CustomResourceDefinitionSpec{
+			Group:   "mygroup.example.com",
+			Version: "v1beta1",
+			Names: apiextensionsv1beta1.CustomResourceDefinitionNames{
+				Plural:   "tables",
+				Singular: "table",
+				Kind:     "Table",
+				ListKind: "TablemList",
+			},
+			Scope: apiextensionsv1beta1.ClusterScoped,
+			AdditionalPrinterColumns: []apiextensionsv1beta1.CustomResourceColumnDefinition{
+				{Name: "Age", Type: "date", JSONPath: ".metadata.creationTimestamp"},
+				{Name: "Alpha", Type: "string", JSONPath: ".spec.alpha"},
+				{Name: "Beta", Type: "integer", Description: "the beta field", Format: "int64", Priority: 42, JSONPath: ".spec.beta"},
+				{Name: "Gamma", Type: "integer", Description: "a column with wrongly typed values", JSONPath: ".spec.gamma"},
+			},
+		},
+	}
+}
+
+func newTableInstance(name string) *unstructured.Unstructured {
+	return &unstructured.Unstructured{
+		Object: map[string]interface{}{
+			"apiVersion": "mygroup.example.com/v1beta1",
+			"kind":       "Table",
+			"metadata": map[string]interface{}{
+				"name": name,
+			},
+			"spec": map[string]interface{}{
+				"alpha": "foo_123",
+				"beta":  10,
+				"gamma": "bar",
+				"delta": "hello",
+			},
+		},
+	}
+}
+
+func TestTableGet(t *testing.T) {
+	stopCh, config, err := testserver.StartDefaultServer()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer close(stopCh)
+
+	apiExtensionClient, err := clientset.NewForConfig(config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dynamicClient, err := dynamic.NewForConfig(config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	crd := newTableCRD()
+	crd, err = testserver.CreateNewCustomResourceDefinition(crd, apiExtensionClient, dynamicClient)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	crd, err = apiExtensionClient.ApiextensionsV1beta1().CustomResourceDefinitions().Get(crd.Name, metav1.GetOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("table crd created: %#v", crd)
+
+	crClient := newNamespacedCustomResourceClient("", dynamicClient, crd)
+	foo, err := crClient.Create(newTableInstance("foo"))
+	if err != nil {
+		t.Fatalf("unable to create noxu instance: %v", err)
+	}
+	t.Logf("foo created: %#v", foo.UnstructuredContent())
+
+	gv := schema.GroupVersion{Group: crd.Spec.Group, Version: crd.Spec.Version}
+	gvk := gv.WithKind(crd.Spec.Names.Kind)
+
+	scheme := runtime.NewScheme()
+	codecs := serializer.NewCodecFactory(scheme)
+	parameterCodec := runtime.NewParameterCodec(scheme)
+	metav1.AddToGroupVersion(scheme, gv)
+	scheme.AddKnownTypes(gv, &metav1beta1.Table{}, &metav1beta1.TableOptions{})
+	scheme.AddKnownTypes(metav1beta1.SchemeGroupVersion, &metav1beta1.Table{}, &metav1beta1.TableOptions{})
+
+	crConfig := *config
+	crConfig.GroupVersion = &gv
+	crConfig.APIPath = "/apis"
+	crConfig.NegotiatedSerializer = serializer.DirectCodecFactory{CodecFactory: codecs}
+	crRestClient, err := rest.RESTClientFor(&crConfig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ret, err := crRestClient.Get().
+		Resource(crd.Spec.Names.Plural).
+		SetHeader("Accept", fmt.Sprintf("application/json;as=Table;v=%s;g=%s, application/json", metav1beta1.SchemeGroupVersion.Version, metav1beta1.GroupName)).
+		VersionedParams(&metav1beta1.TableOptions{}, parameterCodec).
+		Do().
+		Get()
+	if err != nil {
+		t.Fatalf("failed to list %v resources: %v", gvk, err)
+	}
+
+	tbl, ok := ret.(*metav1beta1.Table)
+	if !ok {
+		t.Fatalf("expected metav1beta1.Table, got %T", ret)
+	}
+	t.Logf("%v table list: %#v", gvk, tbl)
+
+	if got, expected := len(tbl.ColumnDefinitions), 5; got != expected {
+		t.Errorf("expected %d headers, got %d", expected, got)
+	} else {
+		alpha := metav1beta1.TableColumnDefinition{Name: "Alpha", Type: "string", Format: "", Description: "Custom resource definition column (in JSONPath format): .spec.alpha", Priority: 0}
+		if got, expected := tbl.ColumnDefinitions[2], alpha; got != expected {
+			t.Errorf("expected column definition %#v, got %#v", expected, got)
+		}
+
+		beta := metav1beta1.TableColumnDefinition{Name: "Beta", Type: "integer", Format: "int64", Description: "the beta field", Priority: 42}
+		if got, expected := tbl.ColumnDefinitions[3], beta; got != expected {
+			t.Errorf("expected column definition %#v, got %#v", expected, got)
+		}
+
+		gamma := metav1beta1.TableColumnDefinition{Name: "Gamma", Type: "integer", Description: "a column with wrongly typed values"}
+		if got, expected := tbl.ColumnDefinitions[4], gamma; got != expected {
+			t.Errorf("expected column definition %#v, got %#v", expected, got)
+		}
+	}
+	if got, expected := len(tbl.Rows), 1; got != expected {
+		t.Errorf("expected %d rows, got %d", expected, got)
+	} else if got, expected := len(tbl.Rows[0].Cells), 5; got != expected {
+		t.Errorf("expected %d cells, got %d", expected, got)
+	} else {
+		if got, expected := tbl.Rows[0].Cells[0], "foo"; got != expected {
+			t.Errorf("expected cell[0] to equal %q, got %q", expected, got)
+		}
+		if got, expected := tbl.Rows[0].Cells[2], "foo_123"; got != expected {
+			t.Errorf("expected cell[2] to equal %q, got %q", expected, got)
+		}
+		if got, expected := tbl.Rows[0].Cells[3], int64(10); got != expected {
+			t.Errorf("expected cell[3] to equal %#v, got %#v", expected, got)
+		}
+		if got, expected := tbl.Rows[0].Cells[4], interface{}(nil); got != expected {
+			t.Errorf("expected cell[3] to equal %#v although the type does not match the column, got %#v", expected, got)
+		}
+	}
+}

staging/src/k8s.io/apimachinery/pkg/api/meta/table/table.go

@@ -53,7 +53,7 @@ func MetaToTableRow(obj runtime.Object, rowFn func(obj runtime.Object, m metav1.
 	row := metav1beta1.TableRow{
 		Object: runtime.RawExtension{Object: obj},
 	}
-	row.Cells, err = rowFn(obj, m, m.GetName(), translateTimestamp(m.GetCreationTimestamp()))
+	row.Cells, err = rowFn(obj, m, m.GetName(), ConvertToHumanReadableDateType(m.GetCreationTimestamp()))
 	if err != nil {
 		return nil, err
 	}
@@ -61,9 +61,9 @@ func MetaToTableRow(obj runtime.Object, rowFn func(obj runtime.Object, m metav1.
 	return rows, nil
 }
 
-// translateTimestamp returns the elapsed time since timestamp in
+// ConvertToHumanReadableDateType returns the elapsed time since timestamp in
 // human-readable approximation.
-func translateTimestamp(timestamp metav1.Time) string {
+func ConvertToHumanReadableDateType(timestamp metav1.Time) string {
 	if timestamp.IsZero() {
 		return "<unknown>"
 	}

staging/src/k8s.io/apiserver/pkg/registry/rest/resttest/resttest.go

@@ -1320,7 +1320,7 @@ func (t *Tester) testListTableConversion(obj runtime.Object, assignFn AssignFunc
 			t.Errorf("column %d has no name", j)
 		}
 		switch column.Type {
-		case "string", "date", "integer":
+		case "string", "date", "integer", "number", "boolean":
 		default:
 			t.Errorf("column %d has unexpected type: %q", j, column.Type)
 		}
@@ -1342,13 +1342,14 @@ func (t *Tester) testListTableConversion(obj runtime.Object, assignFn AssignFunc
 	}
 	for i, row := range table.Rows {
 		if len(row.Cells) != len(table.ColumnDefinitions) {
-			t.Errorf("row %d did not have the correct number of cells: %d in %v", i, len(table.ColumnDefinitions), row.Cells)
+			t.Errorf("row %d did not have the correct number of cells: %d in %v, expected %d", i, len(row.Cells), row.Cells, len(table.ColumnDefinitions))
 		}
 		for j, cell := range row.Cells {
 			// do not add to this test without discussion - may break clients
 			switch cell.(type) {
 			case float64, int64, int32, int, string, bool:
 			case []interface{}:
+			case nil:
 			default:
 				t.Errorf("row %d, cell %d has an unrecognized type, only JSON serialization safe types are allowed: %T ", i, j, cell)
 			}