Add library function for copying directory

utils.go

@@ -27,9 +27,11 @@ import (
 	"io/ioutil"
 	"os"
 	"os/exec"
+	"path"
 	"regexp"
 	"strconv"
 	"strings"
+	"syscall"
 
 	"github.com/canonical/edgex-snap-hooks/v2/log"
 	"github.com/canonical/edgex-snap-hooks/v2/options"
@@ -82,6 +84,48 @@ func CopyFile(srcPath, destPath string) error {
 	return nil
 }
 
+// CopyDir copies a whole directory recursively
+// snippet from https://blog.depa.do/post/copy-files-and-directories-in-go
+func CopyDir(srcPath string, dstPath string) error {
+	var err error
+	var fds []os.FileInfo
+	var srcinfo os.FileInfo
+
+	srcinfo, err = os.Stat(srcPath)
+	if err != nil {
+		return err
+	}
+
+	oldMask := syscall.Umask(0)
+	defer syscall.Umask(oldMask)
+
+	err = os.MkdirAll(dstPath, srcinfo.Mode())
+	if err != nil {
+		return err
+	}
+
+	if fds, err = ioutil.ReadDir(srcPath); err != nil {
+		return err
+	}
+	for _, fd := range fds {
+		srcfp := path.Join(srcPath, fd.Name())
+		dstfp := path.Join(dstPath, fd.Name())
+
+		if fd.IsDir() {
+			err = CopyDir(srcfp, dstfp)
+			if err != nil {
+				return err
+			}
+		} else {
+			err = CopyFile(srcfp, dstfp)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 // CopyFileReplace copies a file within the snap and replaces strings using
 // the string/replace values in the rStrings parameter.
 func CopyFileReplace(srcPath, destPath string, rStrings map[string]string) error {

utils_test.go

@@ -147,3 +147,28 @@ func getConfigValue(t *testing.T, key string) string {
 	require.NoError(t, err, "Error getting config value via snapctl.")
 	return strings.TrimSpace(string(out))
 }
+
+func TestCopyFile(t *testing.T) {
+	tmpdir := t.TempDir()
+	tmpfile, _ := os.CreateTemp(tmpdir, "tmpSrcFile")
+	srcPath := tmpfile.Name()
+
+	tmpdir = t.TempDir()
+	tmpfile, _ = os.CreateTemp(tmpdir, "tmpDstFile")
+	dstPath := tmpfile.Name()
+
+	require.NoError(t, CopyFile(srcPath, dstPath), "Error copying file.")
+}
+
+func TestCopyDir(t *testing.T) {
+	tmpdir := t.TempDir()
+	tmpSrcDir, _ := os.MkdirTemp(tmpdir, "tmpSrcDir")
+	os.CreateTemp(tmpSrcDir, "tmpSrcFile1")
+	os.CreateTemp(tmpSrcDir, "tmpSrcFile2")
+	os.CreateTemp(tmpSrcDir, "tmpSrcFile3")
+
+	tmpdir = t.TempDir()
+	tmpDstDir, _ := os.MkdirTemp(tmpdir, "tmpDstDir")
+
+	require.NoError(t, CopyDir(tmpSrcDir, tmpDstDir), "Error copying directory.")
+}