Copyfile

kyaml/copyutil/copyutil.go

@@ -131,3 +131,49 @@ func Diff(sourceDir, destDir string) (sets.String, error) {
 	// return the differing files
 	return diff, nil
 }
+
+// SyncFile copies file from src file path to a dst file path by replacement
+// deletes dst file if src file doesn't exist
+func SyncFile(src, dst string) error {
+	srcFileInfo, err := os.Stat(src)
+	if err != nil {
+		// delete dst if source doesn't exist
+		if err = deleteFile(dst); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	input, err := ioutil.ReadFile(src)
+	if err != nil {
+		return err
+	}
+
+	var filePerm os.FileMode
+
+	// get the destination file perm if file exists
+	dstFileInfo, err := os.Stat(dst)
+	if err != nil {
+		// get source file perm if destination file doesn't exist
+		filePerm = srcFileInfo.Mode().Perm()
+	} else {
+		filePerm = dstFileInfo.Mode().Perm()
+	}
+
+	err = ioutil.WriteFile(dst, input, filePerm)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// deleteFile deletes file from path, returns no error if file doesn't exist
+func deleteFile(path string) error {
+	_, err := os.Stat(path)
+	if err != nil {
+		// return nil if file doesn't exist
+		return nil
+	}
+	return os.Remove(path)
+}

kyaml/copyutil/copyutil_test.go

@@ -8,6 +8,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -203,3 +204,60 @@ func TestDiff_skipGitDest(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Empty(t, diff.List())
 }
+
+// TestSyncFile tests if destination file is replaced by source file content
+func TestSyncFile(t *testing.T) {
+	d1, err := ioutil.TempDir("", "")
+	assert.NoError(t, err)
+	d2, err := ioutil.TempDir("", "")
+	assert.NoError(t, err)
+	f1Name := d1 + "/temp.txt"
+	f2Name := d2 + "/temp.txt"
+	err = ioutil.WriteFile(f1Name, []byte("abc"), 0600)
+	assert.NoError(t, err)
+	err = ioutil.WriteFile(f2Name, []byte("def"), 0644)
+	assert.NoError(t, err)
+	err = SyncFile(f1Name, f2Name)
+	assert.NoError(t, err)
+	actual, err := ioutil.ReadFile(f2Name)
+	assert.NoError(t, err)
+	assert.Equal(t, "abc", string(actual))
+	dstFileInfo, _ := os.Stat(f2Name)
+	assert.Equal(t, "-rw-r--r--", dstFileInfo.Mode().String())
+}
+
+// TestSyncFileNoDestFile tests if new file is created at destination with source file content
+func TestSyncFileNoDestFile(t *testing.T) {
+	d1, err := ioutil.TempDir("", "")
+	assert.NoError(t, err)
+	d2, err := ioutil.TempDir("", "")
+	assert.NoError(t, err)
+	f1Name := d1 + "/temp.txt"
+	f2Name := d2 + "/temp.txt"
+	err = ioutil.WriteFile(f1Name, []byte("abc"), 0644)
+	assert.NoError(t, err)
+	err = SyncFile(f1Name, f2Name)
+	assert.NoError(t, err)
+	actual, err := ioutil.ReadFile(f2Name)
+	assert.NoError(t, err)
+	assert.Equal(t, "abc", string(actual))
+	dstFileInfo, _ := os.Stat(f2Name)
+	assert.Equal(t, "-rw-r--r--", dstFileInfo.Mode().String())
+}
+
+// TestSyncFileNoSrcFile tests if destination file is deleted if source file doesn't exist
+func TestSyncFileNoSrcFile(t *testing.T) {
+	d1, err := ioutil.TempDir("", "")
+	assert.NoError(t, err)
+	d2, err := ioutil.TempDir("", "")
+	assert.NoError(t, err)
+	f1Name := d1 + "/temp.txt"
+	f2Name := d2 + "/temp.txt"
+	err = ioutil.WriteFile(f2Name, []byte("abc"), 0644)
+	assert.NoError(t, err)
+	err = SyncFile(f1Name, f2Name)
+	assert.NoError(t, err)
+	_, err = ioutil.ReadFile(f2Name)
+	assert.Error(t, err)
+	assert.True(t, strings.Contains(err.Error(), "no such file or directory"))
+}