Merge pull request #38112 from juanvallejo/jvallejo/add-output-format-support-kubectl-create

Automatic merge from submit-queue

Add json,yaml output format support to kubectl create, kubectl apply

Fixes: https://github.com/kubernetes/kubernetes/issues/37390

**Release note**:
```release-note
Added support for printing in all supported `--output` formats to `kubectl create ...` and `kubectl apply ...`
```

This patch adds the ability to specify an output format other than
"name" to `kubectl create ...`. It can be used in conjunction with the
`--dry-run` option. Converts unstructured objects into known types in
order to support all `--output` values.

The patch prints `*resource.Info`s returned by the server. If a resource does not yet exist (and the `--dry-run` option is not set), the resource is created and printed in the specified format.

@kubernetes/cli-review @fabianofranz

pkg/kubectl/cmd/apply.go

@@ -100,7 +100,6 @@ func NewCmdApply(f cmdutil.Factory, out, errOut io.Writer) *cobra.Command {
 		Example: apply_example,
 		Run: func(cmd *cobra.Command, args []string) {
 			cmdutil.CheckErr(validateArgs(cmd, args))
-			cmdutil.CheckErr(cmdutil.ValidateOutputArgs(cmd))
 			cmdutil.CheckErr(validatePruneAll(options.Prune, cmdutil.GetFlagBool(cmd, "all"), options.Selector))
 			cmdutil.CheckErr(RunApply(f, cmd, out, errOut, &options))
 		},
@@ -164,7 +163,6 @@ func parsePruneResources(gvks []string) ([]pruneResource, error) {
 }
 
 func RunApply(f cmdutil.Factory, cmd *cobra.Command, out, errOut io.Writer, options *ApplyOptions) error {
-	shortOutput := cmdutil.GetFlagString(cmd, "output") == "name"
 	schema, err := f.Validator(cmdutil.GetFlagBool(cmd, "validate"), cmdutil.GetFlagString(cmd, "schema-cache-dir"))
 	if err != nil {
 		return err
@@ -197,6 +195,8 @@ func RunApply(f cmdutil.Factory, cmd *cobra.Command, out, errOut io.Writer, opti
 	}
 
 	dryRun := cmdutil.GetFlagBool(cmd, "dry-run")
+	output := cmdutil.GetFlagString(cmd, "output")
+	shortOutput := output == "name"
 
 	encoder := f.JSONEncoder()
 	decoder := f.Decoder(false)
@@ -253,6 +253,9 @@ func RunApply(f cmdutil.Factory, cmd *cobra.Command, out, errOut io.Writer, opti
 			}
 
 			count++
+			if len(output) > 0 && !shortOutput {
+				return cmdutil.PrintResourceInfoForCommand(cmd, info, f, out)
+			}
 			cmdutil.PrintSuccess(mapper, shortOutput, out, info.Mapping.Resource, info.Name, dryRun, "created")
 			return nil
 		}
@@ -304,6 +307,9 @@ func RunApply(f cmdutil.Factory, cmd *cobra.Command, out, errOut io.Writer, opti
 			}
 		}
 		count++
+		if len(output) > 0 && !shortOutput {
+			return cmdutil.PrintResourceInfoForCommand(cmd, info, f, out)
+		}
 		cmdutil.PrintSuccess(mapper, shortOutput, out, info.Mapping.Resource, info.Name, dryRun, "configured")
 		return nil
 	})

pkg/kubectl/cmd/create.go

@@ -131,6 +131,7 @@ func RunCreate(f cmdutil.Factory, cmd *cobra.Command, out, errOut io.Writer, opt
 	}
 
 	dryRun := cmdutil.GetFlagBool(cmd, "dry-run")
+	output := cmdutil.GetFlagString(cmd, "output")
 
 	count := 0
 	err = r.Visit(func(info *resource.Info, err error) error {
@@ -154,7 +155,11 @@ func RunCreate(f cmdutil.Factory, cmd *cobra.Command, out, errOut io.Writer, opt
 		}
 
 		count++
-		shortOutput := cmdutil.GetFlagString(cmd, "output") == "name"
+
+		shortOutput := output == "name"
+		if len(output) > 0 && !shortOutput {
+			return cmdutil.PrintResourceInfoForCommand(cmd, info, f, out)
+		}
 		if !shortOutput {
 			f.PrintObjectSpecificMessage(info.Object, out)
 		}

pkg/kubectl/cmd/util/printing.go

@@ -23,6 +23,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api/meta"
 	"k8s.io/kubernetes/pkg/kubectl"
+	"k8s.io/kubernetes/pkg/kubectl/resource"
 	"k8s.io/kubernetes/pkg/runtime/schema"
 
 	"github.com/spf13/cobra"
@@ -133,6 +134,24 @@ func PrinterForCommand(cmd *cobra.Command) (kubectl.ResourcePrinter, bool, error
 	return maybeWrapSortingPrinter(cmd, printer), generic, nil
 }
 
+// PrintResourceInfoForCommand receives a *cobra.Command and a *resource.Info and
+// attempts to print an info object based on the specified output format. If the
+// object passed is non-generic, it attempts to print the object using a HumanReadablePrinter.
+// Requires that printer flags have been added to cmd (see AddPrinterFlags).
+func PrintResourceInfoForCommand(cmd *cobra.Command, info *resource.Info, f Factory, out io.Writer) error {
+	printer, generic, err := PrinterForCommand(cmd)
+	if err != nil {
+		return err
+	}
+	if !generic || printer == nil {
+		printer, err = f.PrinterForMapping(cmd, nil, false)
+		if err != nil {
+			return err
+		}
+	}
+	return printer.PrintObj(info.Object, out)
+}
+
 func maybeWrapSortingPrinter(cmd *cobra.Command, printer kubectl.ResourcePrinter) kubectl.ResourcePrinter {
 	sorting, err := cmd.Flags().GetString("sort-by")
 	if err != nil {