Dump stdin to a temporary file in kubectl replace --force

pkg/kubectl/cmd/replace.go

@@ -19,7 +19,9 @@ package cmd
 import (
 	"fmt"
 	"io"
+	"io/ioutil"
 	"os"
+	"path/filepath"
 
 	"github.com/spf13/cobra"
 
@@ -131,6 +133,22 @@ func forceReplace(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []
 		return err
 	}
 
+	for i, filename := range filenames {
+		if filename == "-" {
+			tempDir, err := ioutil.TempDir("", "kubectl_replace_")
+			if err != nil {
+				return err
+			}
+			defer os.RemoveAll(tempDir)
+			tempFilename := filepath.Join(tempDir, "resource.stdin")
+			err = cmdutil.DumpReaderToFile(os.Stdin, tempFilename)
+			if err != nil {
+				return err
+			}
+			filenames[i] = tempFilename
+		}
+	}
+
 	mapper, typer := f.Object()
 	r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand()).
 		ContinueOnError().

pkg/kubectl/cmd/util/helpers.go

@@ -406,3 +406,28 @@ func Merge(dst runtime.Object, fragment, kind string) (runtime.Object, error) {
 	}
 	return out, nil
 }
+
+// DumpReaderToFile writes all data from the given io.Reader to the specified file
+// (usually for temporary use).
+func DumpReaderToFile(reader io.Reader, filename string) error {
+	f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	defer f.Close()
+	if err != nil {
+		return err
+	}
+	buffer := make([]byte, 1024)
+	for {
+		count, err := reader.Read(buffer)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		_, err = f.Write(buffer[:count])
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

pkg/kubectl/cmd/util/helpers_test.go

@@ -22,6 +22,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
+	"strings"
 	"syscall"
 	"testing"
 
@@ -298,3 +299,25 @@ func TestCheckInvalidErr(t *testing.T) {
 		}
 	}
 }
+
+func TestDumpReaderToFile(t *testing.T) {
+	testString := "TEST STRING"
+	tempFile, err := ioutil.TempFile("", "hlpers_test_dump_")
+	if err != nil {
+		t.Errorf("unexpected error setting up a temporary file %v", err)
+	}
+	defer syscall.Unlink(tempFile.Name())
+	defer tempFile.Close()
+	err = DumpReaderToFile(strings.NewReader(testString), tempFile.Name())
+	if err != nil {
+		t.Errorf("error in DumpReaderToFile: %v", err)
+	}
+	data, err := ioutil.ReadFile(tempFile.Name())
+	if err != nil {
+		t.Errorf("error when reading %s: %v", tempFile, err)
+	}
+	stringData := string(data)
+	if stringData != testString {
+		t.Fatalf("Wrong file content %s != %s", testString, stringData)
+	}
+}

pkg/kubectl/resource/builder.go

@@ -164,7 +164,7 @@ func (b *Builder) Path(paths ...string) *Builder {
 			continue
 		}
 
-		visitors, err := ExpandPathsToFileVisitors(b.mapper, p, false, []string{".json", ".yaml", ".yml"}, b.continueOnError, b.schema)
+		visitors, err := ExpandPathsToFileVisitors(b.mapper, p, false, []string{".json", ".stdin", ".yaml", ".yml"}, b.continueOnError, b.schema)
 		if err != nil {
 			b.errs = append(b.errs, fmt.Errorf("error reading %q: %v", p, err))
 		}