Refactor TLS code

internal/copy/copy.go

@@ -0,0 +1,49 @@
+/*
+© Copyright IBM Corporation 2019
+
+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 copy
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+func CopyFileMode(src, dest string, perm os.FileMode) error {
+	in, err := os.Open(src)
+	if err != nil {
+		return fmt.Errorf("failed to open %s for copy: %v", src, err)
+	}
+	defer in.Close()
+
+	out, err := os.OpenFile(dest, os.O_CREATE|os.O_WRONLY, perm)
+	if err != nil {
+		return fmt.Errorf("failed to open %s for copy: %v", dest, err)
+	}
+	defer out.Close()
+
+	_, err = io.Copy(out, in)
+	if err != nil {
+		return err
+	}
+	err = out.Close()
+	return err
+}
+
+// CopyFile copies the specified file
+func CopyFile(src, dest string) error {
+	return CopyFileMode(src, dest, 0770)
+}