Merge pull request #65786 from juanvallejo/jvallejo/update-template-printer-check

Automatic merge from submit-queue (batch tested with PRs 65715, 65786). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

update --template printer defaulting

**Release note**:
```release-note
NONE
```

Depends on https://github.com/kubernetes/kubernetes/pull/65711
The relevant commit for this PR is the last one (`
fix go-template defaulting for commands w default output format`)

cc @deads2k @soltysh

hack/make-rules/test-cmd-util.sh

@@ -1777,10 +1777,6 @@ run_template_output_tests() {
   output_message=$(kubectl "${kube_flags[@]}" auth reconcile --dry-run -f test/fixtures/pkg/kubectl/cmd/auth/rbac-resource-plus.yaml --template="{{ .metadata.name }}:")
   kube::test::if_has_string "${output_message}" 'testing-CR:testing-CRB:testing-RB:testing-R:'
 
-  # check that "config view" command supports --template output
-  output_message=$(kubectl "${kube_flags[@]}" config view --output=go-template="{{ .kind }}:")
-  kube::test::if_has_string "${output_message}" 'Config'
-
   # check that "create clusterrole" command supports --template output
   output_message=$(kubectl "${kube_flags[@]}" create clusterrole --template="{{ .metadata.name }}:" --verb get myclusterrole  --non-resource-url /logs/ --resource pods)
   kube::test::if_has_string "${output_message}" 'myclusterrole:'
@@ -1901,6 +1897,22 @@ EOF
   output_message=$(kubectl "${kube_flags[@]}" create service nodeport foo --dry-run --tcp=8080 --template="{{ .metadata.name }}:")
   kube::test::if_has_string "${output_message}" 'foo:'
 
+  # check that "config view" ouputs "yaml" as its default output format
+  output_message=$(kubectl "${kube_flags[@]}" config view)
+  kube::test::if_has_string "${output_message}" 'kind: Config'
+
+  # check that "config view" command supports --template output
+  # and that commands that set a default output (yaml in this case),
+  # default to "go-template" as their output format when a --template
+  # value is provided, but no explicit --output format is given.
+  output_message=$(kubectl "${kube_flags[@]}" config view --template="{{ .kind }}:")
+  kube::test::if_has_string "${output_message}" 'Config'
+
+  # check that running a command with both a --template flag and a
+  # non-template --output prefers the non-template output value
+  output_message=$(kubectl "${kube_flags[@]}" create configmap cm --dry-run --template="{{ .metadata.name }}:" --output yaml)
+  kube::test::if_has_string "${output_message}" 'kind: ConfigMap'
+
   # cleanup
   kubectl delete cronjob pi "${kube_flags[@]}"
   kubectl delete pods --all "${kube_flags[@]}"

pkg/kubectl/genericclioptions/print_flags.go

@@ -22,6 +22,8 @@ import (
 	"strings"
 
 	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/kubernetes/pkg/kubectl/genericclioptions/printers"
 )
@@ -62,6 +64,8 @@ type PrintFlags struct {
 	TypeSetterPrinter *printers.TypeSetterPrinter
 
 	OutputFormat    *string
+	outputFlag      *pflag.Flag
+	outputDefaulted bool
 }
 
 func (f *PrintFlags) Complete(successTemplate string) error {
@@ -81,8 +85,12 @@ func (f *PrintFlags) ToPrinter() (printers.ResourcePrinter, error) {
 	if f.OutputFormat != nil {
 		outputFormat = *f.OutputFormat
 	}
-	// for backwards compatibility we want to support a --template argument given, even when no --output format is provided
+	// For backwards compatibility we want to support a --template argument given, even when no --output format is provided.
-	if f.TemplatePrinterFlags != nil && f.TemplatePrinterFlags.TemplateArgument != nil && len(*f.TemplatePrinterFlags.TemplateArgument) > 0 && len(outputFormat) == 0 {
+	// If a default output format has been set, but no explicit output format has been provided via the --output flag, fallback
+	// to honoring the --template argument.
+	if f.TemplatePrinterFlags != nil && f.TemplatePrinterFlags.TemplateArgument != nil &&
+		len(*f.TemplatePrinterFlags.TemplateArgument) > 0 &&
+		(len(outputFormat) == 0 || (f.outputDefaulted && !f.outputFlag.Changed)) {
 		outputFormat = "go-template"
 	}
 
@@ -114,12 +122,14 @@ func (f *PrintFlags) AddFlags(cmd *cobra.Command) {
 
 	if f.OutputFormat != nil {
 		cmd.Flags().StringVarP(f.OutputFormat, "output", "o", *f.OutputFormat, fmt.Sprintf("Output format. One of: %s.", strings.Join(f.AllowedFormats(), "|")))
+		f.outputFlag = cmd.Flag("output")
 	}
 }
 
 // WithDefaultOutput sets a default output format if one is not provided through a flag value
 func (f *PrintFlags) WithDefaultOutput(output string) *PrintFlags {
 	f.OutputFormat = &output
+	f.outputDefaulted = true
 	return f
 }