Move the k8s code generator.

cmd/k8scopy/internal/utils.go

@@ -0,0 +1,32 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package internal
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"os/exec"
+	"strings"
+)
+
+func RunNoOutputCommand(n string, args ...string) {
+	o := RunGetOutputCommand(n, args...)
+	if len(o) > 0 {
+		log.Fatalf("unexpected output: %q", o)
+	}
+}
+
+func RunGetOutputCommand(n string, args ...string) string {
+	cmd := exec.Command(n, args...)
+	var outBuf bytes.Buffer
+	cmd.Stdout = &outBuf
+	var errBuf bytes.Buffer
+	cmd.Stderr = &errBuf
+	if err := cmd.Run(); err != nil {
+		fmt.Printf("err: %q\n", errBuf.String())
+		log.Fatal(err)
+	}
+	return strings.TrimSpace(outBuf.String())
+}