Move, but do not refactor, printers to their own package

This commit is contained in:
Clayton Coleman 2017-02-18 22:40:38 -05:00
parent c36eee2a0c
commit 6d1c7308a5
No known key found for this signature in database
GPG Key ID: 3D16906B4F1C5CB3
17 changed files with 899 additions and 672 deletions

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@ -1,86 +0,0 @@
/*
Copyright 2014 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 kubectl
import (
"sort"
"k8s.io/kubernetes/pkg/api"
"k8s.io/kubernetes/pkg/kubelet/qos"
)
type SortableResourceNames []api.ResourceName
func (list SortableResourceNames) Len() int {
return len(list)
}
func (list SortableResourceNames) Swap(i, j int) {
list[i], list[j] = list[j], list[i]
}
func (list SortableResourceNames) Less(i, j int) bool {
return list[i] < list[j]
}
// SortedResourceNames returns the sorted resource names of a resource list.
func SortedResourceNames(list api.ResourceList) []api.ResourceName {
resources := make([]api.ResourceName, 0, len(list))
for res := range list {
resources = append(resources, res)
}
sort.Sort(SortableResourceNames(resources))
return resources
}
type SortableResourceQuotas []api.ResourceQuota
func (list SortableResourceQuotas) Len() int {
return len(list)
}
func (list SortableResourceQuotas) Swap(i, j int) {
list[i], list[j] = list[j], list[i]
}
func (list SortableResourceQuotas) Less(i, j int) bool {
return list[i].Name < list[j].Name
}
type SortableVolumeMounts []api.VolumeMount
func (list SortableVolumeMounts) Len() int {
return len(list)
}
func (list SortableVolumeMounts) Swap(i, j int) {
list[i], list[j] = list[j], list[i]
}
func (list SortableVolumeMounts) Less(i, j int) bool {
return list[i].MountPath < list[j].MountPath
}
// SortedQoSResourceNames returns the sorted resource names of a QoS list.
func SortedQoSResourceNames(list qos.QOSList) []api.ResourceName {
resources := make([]api.ResourceName, 0, len(list))
for res := range list {
resources = append(resources, api.ResourceName(res))
}
sort.Sort(SortableResourceNames(resources))
return resources
}

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@ -0,0 +1,159 @@
/*
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 printers
import (
"fmt"
"io"
"reflect"
"strings"
"github.com/golang/glog"
)
type handlerEntry struct {
columns []string
columnsWithWide []string
printFunc reflect.Value
args []reflect.Value
}
// HumanReadablePrinter is an implementation of ResourcePrinter which attempts to provide
// more elegant output. It is not threadsafe, but you may call PrintObj repeatedly; headers
// will only be printed if the object type changes. This makes it useful for printing items
// received from watches.
type HumanReadablePrinter struct {
handlerMap map[reflect.Type]*handlerEntry
options PrintOptions
lastType reflect.Type
hiddenObjNum int
}
// NewHumanReadablePrinter creates a HumanReadablePrinter.
func NewHumanReadablePrinter(options PrintOptions) *HumanReadablePrinter {
printer := &HumanReadablePrinter{
handlerMap: make(map[reflect.Type]*handlerEntry),
options: options,
}
printer.addDefaultHandlers()
return printer
}
// formatResourceName receives a resource kind, name, and boolean specifying
// whether or not to update the current name to "kind/name"
func formatResourceName(kind, name string, withKind bool) string {
if !withKind || kind == "" {
return name
}
return kind + "/" + name
}
// GetResourceKind returns the type currently set for a resource
func (h *HumanReadablePrinter) GetResourceKind() string {
return h.options.Kind
}
// EnsurePrintWithKind sets HumanReadablePrinter options "WithKind" to true
// and "Kind" to the string arg it receives, pre-pending this string
// to the "NAME" column in an output of resources.
func (h *HumanReadablePrinter) EnsurePrintWithKind(kind string) {
h.options.WithKind = true
h.options.Kind = kind
}
// EnsurePrintHeaders sets the HumanReadablePrinter option "NoHeaders" to false
// and removes the .lastType that was printed, which forces headers to be
// printed in cases where multiple lists of the same resource are printed
// consecutively, but are separated by non-printer related information.
func (h *HumanReadablePrinter) EnsurePrintHeaders() {
h.options.NoHeaders = false
h.lastType = nil
}
// Handler adds a print handler with a given set of columns to HumanReadablePrinter instance.
// See validatePrintHandlerFunc for required method signature.
func (h *HumanReadablePrinter) Handler(columns, columnsWithWide []string, printFunc interface{}) error {
printFuncValue := reflect.ValueOf(printFunc)
if err := h.validatePrintHandlerFunc(printFuncValue); err != nil {
glog.Errorf("Unable to add print handler: %v", err)
return err
}
objType := printFuncValue.Type().In(0)
h.handlerMap[objType] = &handlerEntry{
columns: columns,
columnsWithWide: columnsWithWide,
printFunc: printFuncValue,
}
return nil
}
// validatePrintHandlerFunc validates print handler signature.
// printFunc is the function that will be called to print an object.
// It must be of the following type:
// func printFunc(object ObjectType, w io.Writer, options PrintOptions) error
// where ObjectType is the type of the object that will be printed.
func (h *HumanReadablePrinter) validatePrintHandlerFunc(printFunc reflect.Value) error {
if printFunc.Kind() != reflect.Func {
return fmt.Errorf("invalid print handler. %#v is not a function", printFunc)
}
funcType := printFunc.Type()
if funcType.NumIn() != 3 || funcType.NumOut() != 1 {
return fmt.Errorf("invalid print handler." +
"Must accept 3 parameters and return 1 value.")
}
if funcType.In(1) != reflect.TypeOf((*io.Writer)(nil)).Elem() ||
funcType.In(2) != reflect.TypeOf((*PrintOptions)(nil)).Elem() ||
funcType.Out(0) != reflect.TypeOf((*error)(nil)).Elem() {
return fmt.Errorf("invalid print handler. The expected signature is: "+
"func handler(obj %v, w io.Writer, options PrintOptions) error", funcType.In(0))
}
return nil
}
func (h *HumanReadablePrinter) HandledResources() []string {
keys := make([]string, 0)
for k := range h.handlerMap {
// k.String looks like "*api.PodList" and we want just "pod"
api := strings.Split(k.String(), ".")
resource := api[len(api)-1]
if strings.HasSuffix(resource, "List") {
continue
}
resource = strings.ToLower(resource)
keys = append(keys, resource)
}
return keys
}
func (h *HumanReadablePrinter) AfterPrint(output io.Writer, res string) error {
return nil
}
func (h *HumanReadablePrinter) unknown(data []byte, w io.Writer) error {
_, err := fmt.Fprintf(w, "Unknown object: %s", string(data))
return err
}
func (h *HumanReadablePrinter) printHeader(columnNames []string, w io.Writer) error {
if _, err := fmt.Fprintf(w, "%s\n", strings.Join(columnNames, "\t")); err != nil {
return err
}
return nil
}

62
pkg/printers/interface.go Normal file
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@ -0,0 +1,62 @@
/*
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 printers
import (
"io"
"k8s.io/apimachinery/pkg/runtime"
)
// ResourcePrinter is an interface that knows how to print runtime objects.
type ResourcePrinter interface {
// Print receives a runtime object, formats it and prints it to a writer.
PrintObj(runtime.Object, io.Writer) error
HandledResources() []string
//Can be used to print out warning/clarifications if needed
//after all objects were printed
AfterPrint(io.Writer, string) error
}
// ResourcePrinterFunc is a function that can print objects
type ResourcePrinterFunc func(runtime.Object, io.Writer) error
// PrintObj implements ResourcePrinter
func (fn ResourcePrinterFunc) PrintObj(obj runtime.Object, w io.Writer) error {
return fn(obj, w)
}
// TODO: implement HandledResources()
func (fn ResourcePrinterFunc) HandledResources() []string {
return []string{}
}
func (fn ResourcePrinterFunc) AfterPrint(io.Writer, string) error {
return nil
}
type PrintOptions struct {
NoHeaders bool
WithNamespace bool
WithKind bool
Wide bool
ShowAll bool
ShowLabels bool
AbsoluteTimestamps bool
Kind string
ColumnLabels []string
}

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@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
limitations under the License.
*/
package kubectl
package internalversion
import (
"bytes"

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@ -1,5 +1,5 @@
/*
Copyright 2014 The Kubernetes Authors.
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.
@ -14,11 +14,10 @@ See the License for the specific language governing permissions and
limitations under the License.
*/
package kubectl
package internalversion
import (
"bytes"
"encoding/json"
"fmt"
"io"
"io/ioutil"
@ -27,18 +26,14 @@ import (
"sort"
"strings"
"text/tabwriter"
"text/template"
"time"
"k8s.io/apimachinery/pkg/api/meta"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
utilerrors "k8s.io/apimachinery/pkg/util/errors"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/client-go/util/jsonpath"
"k8s.io/kubernetes/federation/apis/federation"
"k8s.io/kubernetes/pkg/api"
"k8s.io/kubernetes/pkg/api/events"
@ -52,18 +47,6 @@ import (
"k8s.io/kubernetes/pkg/apis/storage"
storageutil "k8s.io/kubernetes/pkg/apis/storage/util"
"k8s.io/kubernetes/pkg/util/node"
"github.com/ghodss/yaml"
"github.com/golang/glog"
)
const (
tabwriterMinWidth = 10
tabwriterWidth = 4
tabwriterPadding = 3
tabwriterPadChar = ' '
tabwriterFlags = 0
loadBalancerWidth = 16
)
// GetPrinter takes a format type, an optional format argument. It will return true
@ -156,339 +139,6 @@ func GetPrinter(format, formatArgument string, noHeaders, allowMissingTemplateKe
return printer, true, nil
}
// ResourcePrinter is an interface that knows how to print runtime objects.
type ResourcePrinter interface {
// Print receives a runtime object, formats it and prints it to a writer.
PrintObj(runtime.Object, io.Writer) error
HandledResources() []string
//Can be used to print out warning/clarifications if needed
//after all objects were printed
AfterPrint(io.Writer, string) error
}
// ResourcePrinterFunc is a function that can print objects
type ResourcePrinterFunc func(runtime.Object, io.Writer) error
// PrintObj implements ResourcePrinter
func (fn ResourcePrinterFunc) PrintObj(obj runtime.Object, w io.Writer) error {
return fn(obj, w)
}
// TODO: implement HandledResources()
func (fn ResourcePrinterFunc) HandledResources() []string {
return []string{}
}
func (fn ResourcePrinterFunc) AfterPrint(io.Writer, string) error {
return nil
}
// VersionedPrinter takes runtime objects and ensures they are converted to a given API version
// prior to being passed to a nested printer.
type VersionedPrinter struct {
printer ResourcePrinter
converter runtime.ObjectConvertor
versions []schema.GroupVersion
}
// NewVersionedPrinter wraps a printer to convert objects to a known API version prior to printing.
func NewVersionedPrinter(printer ResourcePrinter, converter runtime.ObjectConvertor, versions ...schema.GroupVersion) ResourcePrinter {
return &VersionedPrinter{
printer: printer,
converter: converter,
versions: versions,
}
}
func (p *VersionedPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj implements ResourcePrinter
func (p *VersionedPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
if len(p.versions) == 0 {
return fmt.Errorf("no version specified, object cannot be converted")
}
converted, err := p.converter.ConvertToVersion(obj, schema.GroupVersions(p.versions))
if err != nil {
return err
}
return p.printer.PrintObj(converted, w)
}
// TODO: implement HandledResources()
func (p *VersionedPrinter) HandledResources() []string {
return []string{}
}
// NamePrinter is an implementation of ResourcePrinter which outputs "resource/name" pair of an object.
type NamePrinter struct {
Decoder runtime.Decoder
Typer runtime.ObjectTyper
}
func (p *NamePrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj is an implementation of ResourcePrinter.PrintObj which decodes the object
// and print "resource/name" pair. If the object is a List, print all items in it.
func (p *NamePrinter) PrintObj(obj runtime.Object, w io.Writer) error {
if meta.IsListType(obj) {
items, err := meta.ExtractList(obj)
if err != nil {
return err
}
if errs := runtime.DecodeList(items, p.Decoder, unstructured.UnstructuredJSONScheme); len(errs) > 0 {
return utilerrors.NewAggregate(errs)
}
for _, obj := range items {
if err := p.PrintObj(obj, w); err != nil {
return err
}
}
return nil
}
name := "<unknown>"
if acc, err := meta.Accessor(obj); err == nil {
if n := acc.GetName(); len(n) > 0 {
name = n
}
}
if kind := obj.GetObjectKind().GroupVersionKind(); len(kind.Kind) == 0 {
// this is the old code. It's unnecessary on decoded external objects, but on internal objects
// you may have to do it. Tests are definitely calling it with internals and I'm not sure who else
// is
if gvks, _, err := p.Typer.ObjectKinds(obj); err == nil {
// TODO: this is wrong, it assumes that meta knows about all Kinds - should take a RESTMapper
_, resource := meta.KindToResource(gvks[0])
fmt.Fprintf(w, "%s/%s\n", resource.Resource, name)
} else {
fmt.Fprintf(w, "<unknown>/%s\n", name)
}
} else {
// TODO: this is wrong, it assumes that meta knows about all Kinds - should take a RESTMapper
_, resource := meta.KindToResource(kind)
fmt.Fprintf(w, "%s/%s\n", resource.Resource, name)
}
return nil
}
// TODO: implement HandledResources()
func (p *NamePrinter) HandledResources() []string {
return []string{}
}
// JSONPrinter is an implementation of ResourcePrinter which outputs an object as JSON.
type JSONPrinter struct {
}
func (p *JSONPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj is an implementation of ResourcePrinter.PrintObj which simply writes the object to the Writer.
func (p *JSONPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
switch obj := obj.(type) {
case *runtime.Unknown:
var buf bytes.Buffer
err := json.Indent(&buf, obj.Raw, "", " ")
if err != nil {
return err
}
buf.WriteRune('\n')
_, err = buf.WriteTo(w)
return err
}
data, err := json.MarshalIndent(obj, "", " ")
if err != nil {
return err
}
data = append(data, '\n')
_, err = w.Write(data)
return err
}
// TODO: implement HandledResources()
func (p *JSONPrinter) HandledResources() []string {
return []string{}
}
// YAMLPrinter is an implementation of ResourcePrinter which outputs an object as YAML.
// The input object is assumed to be in the internal version of an API and is converted
// to the given version first.
type YAMLPrinter struct {
version string
converter runtime.ObjectConvertor
}
func (p *YAMLPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj prints the data as YAML.
func (p *YAMLPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
switch obj := obj.(type) {
case *runtime.Unknown:
data, err := yaml.JSONToYAML(obj.Raw)
if err != nil {
return err
}
_, err = w.Write(data)
return err
}
output, err := yaml.Marshal(obj)
if err != nil {
return err
}
_, err = fmt.Fprint(w, string(output))
return err
}
// TODO: implement HandledResources()
func (p *YAMLPrinter) HandledResources() []string {
return []string{}
}
type handlerEntry struct {
columns []string
columnsWithWide []string
printFunc reflect.Value
args []reflect.Value
}
type PrintOptions struct {
NoHeaders bool
WithNamespace bool
WithKind bool
Wide bool
ShowAll bool
ShowLabels bool
AbsoluteTimestamps bool
Kind string
ColumnLabels []string
}
// HumanReadablePrinter is an implementation of ResourcePrinter which attempts to provide
// more elegant output. It is not threadsafe, but you may call PrintObj repeatedly; headers
// will only be printed if the object type changes. This makes it useful for printing items
// received from watches.
type HumanReadablePrinter struct {
handlerMap map[reflect.Type]*handlerEntry
options PrintOptions
lastType reflect.Type
hiddenObjNum int
}
// NewHumanReadablePrinter creates a HumanReadablePrinter.
func NewHumanReadablePrinter(options PrintOptions) *HumanReadablePrinter {
printer := &HumanReadablePrinter{
handlerMap: make(map[reflect.Type]*handlerEntry),
options: options,
}
printer.addDefaultHandlers()
return printer
}
// formatResourceName receives a resource kind, name, and boolean specifying
// whether or not to update the current name to "kind/name"
func formatResourceName(kind, name string, withKind bool) string {
if !withKind || kind == "" {
return name
}
return kind + "/" + name
}
// GetResourceKind returns the type currently set for a resource
func (h *HumanReadablePrinter) GetResourceKind() string {
return h.options.Kind
}
// EnsurePrintWithKind sets HumanReadablePrinter options "WithKind" to true
// and "Kind" to the string arg it receives, pre-pending this string
// to the "NAME" column in an output of resources.
func (h *HumanReadablePrinter) EnsurePrintWithKind(kind string) {
h.options.WithKind = true
h.options.Kind = kind
}
// EnsurePrintHeaders sets the HumanReadablePrinter option "NoHeaders" to false
// and removes the .lastType that was printed, which forces headers to be
// printed in cases where multiple lists of the same resource are printed
// consecutively, but are separated by non-printer related information.
func (h *HumanReadablePrinter) EnsurePrintHeaders() {
h.options.NoHeaders = false
h.lastType = nil
}
// Handler adds a print handler with a given set of columns to HumanReadablePrinter instance.
// See validatePrintHandlerFunc for required method signature.
func (h *HumanReadablePrinter) Handler(columns, columnsWithWide []string, printFunc interface{}) error {
printFuncValue := reflect.ValueOf(printFunc)
if err := h.validatePrintHandlerFunc(printFuncValue); err != nil {
glog.Errorf("Unable to add print handler: %v", err)
return err
}
objType := printFuncValue.Type().In(0)
h.handlerMap[objType] = &handlerEntry{
columns: columns,
columnsWithWide: columnsWithWide,
printFunc: printFuncValue,
}
return nil
}
// validatePrintHandlerFunc validates print handler signature.
// printFunc is the function that will be called to print an object.
// It must be of the following type:
// func printFunc(object ObjectType, w io.Writer, options PrintOptions) error
// where ObjectType is the type of the object that will be printed.
func (h *HumanReadablePrinter) validatePrintHandlerFunc(printFunc reflect.Value) error {
if printFunc.Kind() != reflect.Func {
return fmt.Errorf("invalid print handler. %#v is not a function", printFunc)
}
funcType := printFunc.Type()
if funcType.NumIn() != 3 || funcType.NumOut() != 1 {
return fmt.Errorf("invalid print handler." +
"Must accept 3 parameters and return 1 value.")
}
if funcType.In(1) != reflect.TypeOf((*io.Writer)(nil)).Elem() ||
funcType.In(2) != reflect.TypeOf((*PrintOptions)(nil)).Elem() ||
funcType.Out(0) != reflect.TypeOf((*error)(nil)).Elem() {
return fmt.Errorf("invalid print handler. The expected signature is: "+
"func handler(obj %v, w io.Writer, options PrintOptions) error", funcType.In(0))
}
return nil
}
func (h *HumanReadablePrinter) HandledResources() []string {
keys := make([]string, 0)
for k := range h.handlerMap {
// k.String looks like "*api.PodList" and we want just "pod"
api := strings.Split(k.String(), ".")
resource := api[len(api)-1]
if strings.HasSuffix(resource, "List") {
continue
}
resource = strings.ToLower(resource)
keys = append(keys, resource)
}
return keys
}
func (h *HumanReadablePrinter) AfterPrint(output io.Writer, res string) error {
return nil
}
// NOTE: When adding a new resource type here, please update the list
// pkg/kubectl/cmd/get.go to reflect the new resource type.
var (
@ -544,7 +194,7 @@ var (
certificateSigningRequestColumns = []string{"NAME", "AGE", "REQUESTOR", "CONDITION"}
)
func (h *HumanReadablePrinter) printPod(pod *api.Pod, w io.Writer, options PrintOptions) error {
func printPod(pod *api.Pod, w io.Writer, options PrintOptions) error {
if err := printPodBase(pod, w, options); err != nil {
return err
}
@ -552,7 +202,7 @@ func (h *HumanReadablePrinter) printPod(pod *api.Pod, w io.Writer, options Print
return nil
}
func (h *HumanReadablePrinter) printPodList(podList *api.PodList, w io.Writer, options PrintOptions) error {
func printPodList(podList *api.PodList, w io.Writer, options PrintOptions) error {
for _, pod := range podList.Items {
if err := printPodBase(&pod, w, options); err != nil {
return err
@ -638,18 +288,6 @@ func (h *HumanReadablePrinter) addDefaultHandlers() {
h.Handler(statusColumns, nil, printStatus)
}
func (h *HumanReadablePrinter) unknown(data []byte, w io.Writer) error {
_, err := fmt.Fprintf(w, "Unknown object: %s", string(data))
return err
}
func (h *HumanReadablePrinter) printHeader(columnNames []string, w io.Writer) error {
if _, err := fmt.Fprintf(w, "%s\n", strings.Join(columnNames, "\t")); err != nil {
return err
}
return nil
}
// Pass ports=nil for all ports.
func formatEndpoints(endpoints *api.Endpoints, ports sets.String) string {
if len(endpoints.Subsets) == 0 {
@ -2449,11 +2087,6 @@ func formatShowLabelsHeader(showLabels bool, t reflect.Type) []string {
return nil
}
// GetNewTabWriter returns a tabwriter that translates tabbed columns in input into properly aligned text.
func GetNewTabWriter(output io.Writer) *tabwriter.Writer {
return tabwriter.NewWriter(output, tabwriterMinWidth, tabwriterWidth, tabwriterPadding, tabwriterPadChar, tabwriterFlags)
}
// PrintObj prints the obj in a human-friendly format according to the type of the obj.
func (h *HumanReadablePrinter) PrintObj(obj runtime.Object, output io.Writer) error {
// if output is a tabwriter (when it's called by kubectl get), we use it; create a new tabwriter otherwise
@ -2563,90 +2196,6 @@ func printUnstructured(unstructured runtime.Unstructured, w io.Writer, options P
return nil
}
// TemplatePrinter is an implementation of ResourcePrinter which formats data with a Go Template.
type TemplatePrinter struct {
rawTemplate string
template *template.Template
}
func NewTemplatePrinter(tmpl []byte) (*TemplatePrinter, error) {
t, err := template.New("output").
Funcs(template.FuncMap{"exists": exists}).
Parse(string(tmpl))
if err != nil {
return nil, err
}
return &TemplatePrinter{
rawTemplate: string(tmpl),
template: t,
}, nil
}
// AllowMissingKeys tells the template engine if missing keys are allowed.
func (p *TemplatePrinter) AllowMissingKeys(allow bool) {
if allow {
p.template.Option("missingkey=default")
} else {
p.template.Option("missingkey=error")
}
}
func (p *TemplatePrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj formats the obj with the Go Template.
func (p *TemplatePrinter) PrintObj(obj runtime.Object, w io.Writer) error {
var data []byte
var err error
data, err = json.Marshal(obj)
if err != nil {
return err
}
out := map[string]interface{}{}
if err := json.Unmarshal(data, &out); err != nil {
return err
}
if err = p.safeExecute(w, out); err != nil {
// It is way easier to debug this stuff when it shows up in
// stdout instead of just stdin. So in addition to returning
// a nice error, also print useful stuff with the writer.
fmt.Fprintf(w, "Error executing template: %v. Printing more information for debugging the template:\n", err)
fmt.Fprintf(w, "\ttemplate was:\n\t\t%v\n", p.rawTemplate)
fmt.Fprintf(w, "\traw data was:\n\t\t%v\n", string(data))
fmt.Fprintf(w, "\tobject given to template engine was:\n\t\t%+v\n\n", out)
return fmt.Errorf("error executing template %q: %v", p.rawTemplate, err)
}
return nil
}
// TODO: implement HandledResources()
func (p *TemplatePrinter) HandledResources() []string {
return []string{}
}
// safeExecute tries to execute the template, but catches panics and returns an error
// should the template engine panic.
func (p *TemplatePrinter) safeExecute(w io.Writer, obj interface{}) error {
var panicErr error
// Sorry for the double anonymous function. There's probably a clever way
// to do this that has the defer'd func setting the value to be returned, but
// that would be even less obvious.
retErr := func() error {
defer func() {
if x := recover(); x != nil {
panicErr = fmt.Errorf("caught panic: %+v", x)
}
}()
return p.template.Execute(w, obj)
}()
if panicErr != nil {
return panicErr
}
return retErr
}
func tabbedString(f func(io.Writer) error) (string, error) {
out := new(tabwriter.Writer)
buf := &bytes.Buffer{}
@ -2662,135 +2211,6 @@ func tabbedString(f func(io.Writer) error) (string, error) {
return str, nil
}
// exists returns true if it would be possible to call the index function
// with these arguments.
//
// TODO: how to document this for users?
//
// index returns the result of indexing its first argument by the following
// arguments. Thus "index x 1 2 3" is, in Go syntax, x[1][2][3]. Each
// indexed item must be a map, slice, or array.
func exists(item interface{}, indices ...interface{}) bool {
v := reflect.ValueOf(item)
for _, i := range indices {
index := reflect.ValueOf(i)
var isNil bool
if v, isNil = indirect(v); isNil {
return false
}
switch v.Kind() {
case reflect.Array, reflect.Slice, reflect.String:
var x int64
switch index.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
x = index.Int()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
x = int64(index.Uint())
default:
return false
}
if x < 0 || x >= int64(v.Len()) {
return false
}
v = v.Index(int(x))
case reflect.Map:
if !index.IsValid() {
index = reflect.Zero(v.Type().Key())
}
if !index.Type().AssignableTo(v.Type().Key()) {
return false
}
if x := v.MapIndex(index); x.IsValid() {
v = x
} else {
v = reflect.Zero(v.Type().Elem())
}
default:
return false
}
}
if _, isNil := indirect(v); isNil {
return false
}
return true
}
// stolen from text/template
// indirect returns the item at the end of indirection, and a bool to indicate if it's nil.
// We indirect through pointers and empty interfaces (only) because
// non-empty interfaces have methods we might need.
func indirect(v reflect.Value) (rv reflect.Value, isNil bool) {
for ; v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface; v = v.Elem() {
if v.IsNil() {
return v, true
}
if v.Kind() == reflect.Interface && v.NumMethod() > 0 {
break
}
}
return v, false
}
// JSONPathPrinter is an implementation of ResourcePrinter which formats data with jsonpath expression.
type JSONPathPrinter struct {
rawTemplate string
*jsonpath.JSONPath
}
func NewJSONPathPrinter(tmpl string) (*JSONPathPrinter, error) {
j := jsonpath.New("out")
if err := j.Parse(tmpl); err != nil {
return nil, err
}
return &JSONPathPrinter{tmpl, j}, nil
}
func (j *JSONPathPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj formats the obj with the JSONPath Template.
func (j *JSONPathPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
var queryObj interface{} = obj
if meta.IsListType(obj) {
data, err := json.Marshal(obj)
if err != nil {
return err
}
queryObj = map[string]interface{}{}
if err := json.Unmarshal(data, &queryObj); err != nil {
return err
}
}
if unknown, ok := obj.(*runtime.Unknown); ok {
data, err := json.Marshal(unknown)
if err != nil {
return err
}
queryObj = map[string]interface{}{}
if err := json.Unmarshal(data, &queryObj); err != nil {
return err
}
}
if unstructured, ok := obj.(*unstructured.Unstructured); ok {
queryObj = unstructured.Object
}
if err := j.JSONPath.Execute(w, queryObj); err != nil {
fmt.Fprintf(w, "Error executing template: %v. Printing more information for debugging the template:\n", err)
fmt.Fprintf(w, "\ttemplate was:\n\t\t%v\n", j.rawTemplate)
fmt.Fprintf(w, "\tobject given to jsonpath engine was:\n\t\t%#v\n\n", queryObj)
return fmt.Errorf("error executing jsonpath %q: %v\n", j.rawTemplate, err)
}
return nil
}
// TODO: implement HandledResources()
func (p *JSONPathPrinter) HandledResources() []string {
return []string{}
}
// formatEventSource formats EventSource as a comma separated string excluding Host when empty
func formatEventSource(es api.EventSource) string {
EventSourceString := []string{es.Component}

View File

@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
limitations under the License.
*/
package kubectl
package internalversion
import (
"bytes"

101
pkg/printers/json.go Normal file
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@ -0,0 +1,101 @@
/*
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 printers
import (
"bytes"
"encoding/json"
"fmt"
"io"
"k8s.io/apimachinery/pkg/runtime"
"github.com/ghodss/yaml"
)
// JSONPrinter is an implementation of ResourcePrinter which outputs an object as JSON.
type JSONPrinter struct {
}
func (p *JSONPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj is an implementation of ResourcePrinter.PrintObj which simply writes the object to the Writer.
func (p *JSONPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
switch obj := obj.(type) {
case *runtime.Unknown:
var buf bytes.Buffer
err := json.Indent(&buf, obj.Raw, "", " ")
if err != nil {
return err
}
buf.WriteRune('\n')
_, err = buf.WriteTo(w)
return err
}
data, err := json.MarshalIndent(obj, "", " ")
if err != nil {
return err
}
data = append(data, '\n')
_, err = w.Write(data)
return err
}
// TODO: implement HandledResources()
func (p *JSONPrinter) HandledResources() []string {
return []string{}
}
// YAMLPrinter is an implementation of ResourcePrinter which outputs an object as YAML.
// The input object is assumed to be in the internal version of an API and is converted
// to the given version first.
type YAMLPrinter struct {
version string
converter runtime.ObjectConvertor
}
func (p *YAMLPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj prints the data as YAML.
func (p *YAMLPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
switch obj := obj.(type) {
case *runtime.Unknown:
data, err := yaml.JSONToYAML(obj.Raw)
if err != nil {
return err
}
_, err = w.Write(data)
return err
}
output, err := yaml.Marshal(obj)
if err != nil {
return err
}
_, err = fmt.Fprint(w, string(output))
return err
}
// TODO: implement HandledResources()
func (p *YAMLPrinter) HandledResources() []string {
return []string{}
}

157
pkg/printers/jsonpath.go Normal file
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@ -0,0 +1,157 @@
/*
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 printers
import (
"encoding/json"
"fmt"
"io"
"reflect"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/client-go/util/jsonpath"
)
// exists returns true if it would be possible to call the index function
// with these arguments.
//
// TODO: how to document this for users?
//
// index returns the result of indexing its first argument by the following
// arguments. Thus "index x 1 2 3" is, in Go syntax, x[1][2][3]. Each
// indexed item must be a map, slice, or array.
func exists(item interface{}, indices ...interface{}) bool {
v := reflect.ValueOf(item)
for _, i := range indices {
index := reflect.ValueOf(i)
var isNil bool
if v, isNil = indirect(v); isNil {
return false
}
switch v.Kind() {
case reflect.Array, reflect.Slice, reflect.String:
var x int64
switch index.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
x = index.Int()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
x = int64(index.Uint())
default:
return false
}
if x < 0 || x >= int64(v.Len()) {
return false
}
v = v.Index(int(x))
case reflect.Map:
if !index.IsValid() {
index = reflect.Zero(v.Type().Key())
}
if !index.Type().AssignableTo(v.Type().Key()) {
return false
}
if x := v.MapIndex(index); x.IsValid() {
v = x
} else {
v = reflect.Zero(v.Type().Elem())
}
default:
return false
}
}
if _, isNil := indirect(v); isNil {
return false
}
return true
}
// stolen from text/template
// indirect returns the item at the end of indirection, and a bool to indicate if it's nil.
// We indirect through pointers and empty interfaces (only) because
// non-empty interfaces have methods we might need.
func indirect(v reflect.Value) (rv reflect.Value, isNil bool) {
for ; v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface; v = v.Elem() {
if v.IsNil() {
return v, true
}
if v.Kind() == reflect.Interface && v.NumMethod() > 0 {
break
}
}
return v, false
}
// JSONPathPrinter is an implementation of ResourcePrinter which formats data with jsonpath expression.
type JSONPathPrinter struct {
rawTemplate string
*jsonpath.JSONPath
}
func NewJSONPathPrinter(tmpl string) (*JSONPathPrinter, error) {
j := jsonpath.New("out")
if err := j.Parse(tmpl); err != nil {
return nil, err
}
return &JSONPathPrinter{tmpl, j}, nil
}
func (j *JSONPathPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj formats the obj with the JSONPath Template.
func (j *JSONPathPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
var queryObj interface{} = obj
if meta.IsListType(obj) {
data, err := json.Marshal(obj)
if err != nil {
return err
}
queryObj = map[string]interface{}{}
if err := json.Unmarshal(data, &queryObj); err != nil {
return err
}
}
if unknown, ok := obj.(*runtime.Unknown); ok {
data, err := json.Marshal(unknown)
if err != nil {
return err
}
queryObj = map[string]interface{}{}
if err := json.Unmarshal(data, &queryObj); err != nil {
return err
}
}
if unstructured, ok := obj.(runtime.Unstructured); ok {
queryObj = unstructured.UnstructuredContent()
}
if err := j.JSONPath.Execute(w, queryObj); err != nil {
fmt.Fprintf(w, "Error executing template: %v. Printing more information for debugging the template:\n", err)
fmt.Fprintf(w, "\ttemplate was:\n\t\t%v\n", j.rawTemplate)
fmt.Fprintf(w, "\tobject given to jsonpath engine was:\n\t\t%#v\n\n", queryObj)
return fmt.Errorf("error executing jsonpath %q: %v\n", j.rawTemplate, err)
}
return nil
}
// TODO: implement HandledResources()
func (p *JSONPathPrinter) HandledResources() []string {
return []string{}
}

89
pkg/printers/name.go Normal file
View File

@ -0,0 +1,89 @@
/*
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 printers
import (
"fmt"
"io"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
"k8s.io/apimachinery/pkg/runtime"
utilerrors "k8s.io/apimachinery/pkg/util/errors"
)
// NamePrinter is an implementation of ResourcePrinter which outputs "resource/name" pair of an object.
type NamePrinter struct {
Decoder runtime.Decoder
Typer runtime.ObjectTyper
}
func (p *NamePrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj is an implementation of ResourcePrinter.PrintObj which decodes the object
// and print "resource/name" pair. If the object is a List, print all items in it.
func (p *NamePrinter) PrintObj(obj runtime.Object, w io.Writer) error {
if meta.IsListType(obj) {
items, err := meta.ExtractList(obj)
if err != nil {
return err
}
if errs := runtime.DecodeList(items, p.Decoder, unstructured.UnstructuredJSONScheme); len(errs) > 0 {
return utilerrors.NewAggregate(errs)
}
for _, obj := range items {
if err := p.PrintObj(obj, w); err != nil {
return err
}
}
return nil
}
name := "<unknown>"
if acc, err := meta.Accessor(obj); err == nil {
if n := acc.GetName(); len(n) > 0 {
name = n
}
}
if kind := obj.GetObjectKind().GroupVersionKind(); len(kind.Kind) == 0 {
// this is the old code. It's unnecessary on decoded external objects, but on internal objects
// you may have to do it. Tests are definitely calling it with internals and I'm not sure who else
// is
if gvks, _, err := p.Typer.ObjectKinds(obj); err == nil {
// TODO: this is wrong, it assumes that meta knows about all Kinds - should take a RESTMapper
_, resource := meta.KindToResource(gvks[0])
fmt.Fprintf(w, "%s/%s\n", resource.Resource, name)
} else {
fmt.Fprintf(w, "<unknown>/%s\n", name)
}
} else {
// TODO: this is wrong, it assumes that meta knows about all Kinds - should take a RESTMapper
_, resource := meta.KindToResource(kind)
fmt.Fprintf(w, "%s/%s\n", resource.Resource, name)
}
return nil
}
// TODO: implement HandledResources()
func (p *NamePrinter) HandledResources() []string {
return []string{}
}

116
pkg/printers/printers.go Normal file
View File

@ -0,0 +1,116 @@
/*
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 printers
import (
"fmt"
"io/ioutil"
"os"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/runtime"
)
// GetStandardPrinter takes a format type, an optional format argument. It will return true
// if the format is generic (untyped), otherwise it will return false. The printer
// is agnostic to schema versions, so you must send arguments to PrintObj in the
// version you wish them to be shown using a VersionedPrinter (typically when
// generic is true).
func GetStandardPrinter(format, formatArgument string, noHeaders, allowMissingTemplateKeys bool, mapper meta.RESTMapper, typer runtime.ObjectTyper, decoders []runtime.Decoder) (ResourcePrinter, bool, error) {
var printer ResourcePrinter
switch format {
case "json":
printer = &JSONPrinter{}
case "yaml":
printer = &YAMLPrinter{}
case "name":
printer = &NamePrinter{
Typer: typer,
Decoders: decoders,
Mapper: mapper,
}
case "template", "go-template":
if len(formatArgument) == 0 {
return nil, false, fmt.Errorf("template format specified but no template given")
}
templatePrinter, err := NewTemplatePrinter([]byte(formatArgument))
if err != nil {
return nil, false, fmt.Errorf("error parsing template %s, %v\n", formatArgument, err)
}
templatePrinter.AllowMissingKeys(allowMissingTemplateKeys)
printer = templatePrinter
case "templatefile", "go-template-file":
if len(formatArgument) == 0 {
return nil, false, fmt.Errorf("templatefile format specified but no template file given")
}
data, err := ioutil.ReadFile(formatArgument)
if err != nil {
return nil, false, fmt.Errorf("error reading template %s, %v\n", formatArgument, err)
}
templatePrinter, err := NewTemplatePrinter(data)
if err != nil {
return nil, false, fmt.Errorf("error parsing template %s, %v\n", string(data), err)
}
templatePrinter.AllowMissingKeys(allowMissingTemplateKeys)
printer = templatePrinter
case "jsonpath":
if len(formatArgument) == 0 {
return nil, false, fmt.Errorf("jsonpath template format specified but no template given")
}
jsonpathPrinter, err := NewJSONPathPrinter(formatArgument)
if err != nil {
return nil, false, fmt.Errorf("error parsing jsonpath %s, %v\n", formatArgument, err)
}
jsonpathPrinter.AllowMissingKeys(allowMissingTemplateKeys)
printer = jsonpathPrinter
case "jsonpath-file":
if len(formatArgument) == 0 {
return nil, false, fmt.Errorf("jsonpath file format specified but no template file file given")
}
data, err := ioutil.ReadFile(formatArgument)
if err != nil {
return nil, false, fmt.Errorf("error reading template %s, %v\n", formatArgument, err)
}
jsonpathPrinter, err := NewJSONPathPrinter(string(data))
if err != nil {
return nil, false, fmt.Errorf("error parsing template %s, %v\n", string(data), err)
}
jsonpathPrinter.AllowMissingKeys(allowMissingTemplateKeys)
printer = jsonpathPrinter
case "custom-columns":
var err error
if printer, err = NewCustomColumnsPrinterFromSpec(formatArgument, decoders[0], noHeaders); err != nil {
return nil, false, err
}
case "custom-columns-file":
file, err := os.Open(formatArgument)
if err != nil {
return nil, false, fmt.Errorf("error reading template %s, %v\n", formatArgument, err)
}
defer file.Close()
if printer, err = NewCustomColumnsPrinterFromTemplate(file, decoders[0]); err != nil {
return nil, false, err
}
case "wide":
fallthrough
case "":
return nil, false, nil
default:
return nil, false, fmt.Errorf("output format %q not recognized", format)
}
return printer, true, nil
}

36
pkg/printers/tabwriter.go Normal file
View File

@ -0,0 +1,36 @@
/*
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 printers
import (
"io"
"text/tabwriter"
)
const (
tabwriterMinWidth = 10
tabwriterWidth = 4
tabwriterPadding = 3
tabwriterPadChar = ' '
tabwriterFlags = 0
loadBalancerWidth = 16
)
// GetNewTabWriter returns a tabwriter that translates tabbed columns in input into properly aligned text.
func GetNewTabWriter(output io.Writer) *tabwriter.Writer {
return tabwriter.NewWriter(output, tabwriterMinWidth, tabwriterWidth, tabwriterPadding, tabwriterPadChar, tabwriterFlags)
}

110
pkg/printers/template.go Normal file
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@ -0,0 +1,110 @@
/*
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 printers
import (
"encoding/json"
"fmt"
"io"
"text/template"
"k8s.io/apimachinery/pkg/runtime"
)
// TemplatePrinter is an implementation of ResourcePrinter which formats data with a Go Template.
type TemplatePrinter struct {
rawTemplate string
template *template.Template
}
func NewTemplatePrinter(tmpl []byte) (*TemplatePrinter, error) {
t, err := template.New("output").
Funcs(template.FuncMap{"exists": exists}).
Parse(string(tmpl))
if err != nil {
return nil, err
}
return &TemplatePrinter{
rawTemplate: string(tmpl),
template: t,
}, nil
}
// AllowMissingKeys tells the template engine if missing keys are allowed.
func (p *TemplatePrinter) AllowMissingKeys(allow bool) {
if allow {
p.template.Option("missingkey=default")
} else {
p.template.Option("missingkey=error")
}
}
func (p *TemplatePrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj formats the obj with the Go Template.
func (p *TemplatePrinter) PrintObj(obj runtime.Object, w io.Writer) error {
var data []byte
var err error
data, err = json.Marshal(obj)
if err != nil {
return err
}
out := map[string]interface{}{}
if err := json.Unmarshal(data, &out); err != nil {
return err
}
if err = p.safeExecute(w, out); err != nil {
// It is way easier to debug this stuff when it shows up in
// stdout instead of just stdin. So in addition to returning
// a nice error, also print useful stuff with the writer.
fmt.Fprintf(w, "Error executing template: %v. Printing more information for debugging the template:\n", err)
fmt.Fprintf(w, "\ttemplate was:\n\t\t%v\n", p.rawTemplate)
fmt.Fprintf(w, "\traw data was:\n\t\t%v\n", string(data))
fmt.Fprintf(w, "\tobject given to template engine was:\n\t\t%+v\n\n", out)
return fmt.Errorf("error executing template %q: %v", p.rawTemplate, err)
}
return nil
}
// TODO: implement HandledResources()
func (p *TemplatePrinter) HandledResources() []string {
return []string{}
}
// safeExecute tries to execute the template, but catches panics and returns an error
// should the template engine panic.
func (p *TemplatePrinter) safeExecute(w io.Writer, obj interface{}) error {
var panicErr error
// Sorry for the double anonymous function. There's probably a clever way
// to do this that has the defer'd func setting the value to be returned, but
// that would be even less obvious.
retErr := func() error {
defer func() {
if x := recover(); x != nil {
panicErr = fmt.Errorf("caught panic: %+v", x)
}
}()
return p.template.Execute(w, obj)
}()
if panicErr != nil {
return panicErr
}
return retErr
}

63
pkg/printers/versioned.go Normal file
View File

@ -0,0 +1,63 @@
/*
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 printers
import (
"fmt"
"io"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
)
// VersionedPrinter takes runtime objects and ensures they are converted to a given API version
// prior to being passed to a nested printer.
type VersionedPrinter struct {
printer ResourcePrinter
converter runtime.ObjectConvertor
versions []schema.GroupVersion
}
// NewVersionedPrinter wraps a printer to convert objects to a known API version prior to printing.
func NewVersionedPrinter(printer ResourcePrinter, converter runtime.ObjectConvertor, versions ...schema.GroupVersion) ResourcePrinter {
return &VersionedPrinter{
printer: printer,
converter: converter,
versions: versions,
}
}
func (p *VersionedPrinter) AfterPrint(w io.Writer, res string) error {
return nil
}
// PrintObj implements ResourcePrinter
func (p *VersionedPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
if len(p.versions) == 0 {
return fmt.Errorf("no version specified, object cannot be converted")
}
converted, err := p.converter.ConvertToVersion(obj, schema.GroupVersions(p.versions))
if err != nil {
return err
}
return p.printer.PrintObj(converted, w)
}
// TODO: implement HandledResources()
func (p *VersionedPrinter) HandledResources() []string {
return []string{}
}