From 45a913ee917faff9b40e7ee2dfbcd1fc375fcb9d Mon Sep 17 00:00:00 2001
From: Abdullahi Yunus <abdoollahikbk@gmail.com>
Date: Wed, 5 Feb 2025 14:36:10 +0100
Subject: [PATCH] lnutils: add createdir util function
This utility function replaces repetitive logic patterns
throughout LND.
---
lnutils/fs.go | 31 +++++++++++++++++
lnutils/fs_test.go | 87 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 118 insertions(+)
create mode 100644 lnutils/fs.go
create mode 100644 lnutils/fs_test.go
diff --git a/lnutils/fs.go b/lnutils/fs.go
new file mode 100644
index 000000000..bc09176cc
--- /dev/null
+++ b/lnutils/fs.go
@@ -0,0 +1,31 @@
+package lnutils
+
+import (
+ "errors"
+ "fmt"
+ "os"
+)
+
+// CreateDir creates a directory if it doesn't exist and also handles
+// symlink-related errors with user-friendly messages. It creates all necessary
+// parent directories with the specified permissions.
+func CreateDir(dir string, perm os.FileMode) error {
+ err := os.MkdirAll(dir, perm)
+ if err == nil {
+ return nil
+ }
+
+ // Show a nicer error message if it's because a symlink
+ // is linked to a directory that does not exist
+ // (probably because it's not mounted).
+ var pathErr *os.PathError
+ if errors.As(err, &pathErr) && os.IsExist(err) {
+ link, lerr := os.Readlink(pathErr.Path)
+ if lerr == nil {
+ return fmt.Errorf("is symlink %s -> %s "+
+ "mounted?", pathErr.Path, link)
+ }
+ }
+
+ return fmt.Errorf("failed to create directory '%s': %w", dir, err)
+}
diff --git a/lnutils/fs_test.go b/lnutils/fs_test.go
new file mode 100644
index 000000000..3e96d4faf
--- /dev/null
+++ b/lnutils/fs_test.go
@@ -0,0 +1,87 @@
+package lnutils
+
+import (
+ "os"
+ "path/filepath"
+ "testing"
+
+ "github.com/stretchr/testify/require"
+)
+
+// TestCreateDir verifies the behavior of CreateDir function in various
+// scenarios:
+// - Creating a new directory when it doesn't exist
+// - Handling an already existing directory
+// - Dealing with symlinks pointing to non-existent directories
+// - Handling invalid paths
+// The test uses a temporary directory and runs multiple test cases to ensure
+// proper directory creation, permission settings, and error handling.
+func TestCreateDir(t *testing.T) {
+ t.Parallel()
+
+ tempDir := t.TempDir()
+
+ tests := []struct {
+ name string
+ setup func() string
+ wantError bool
+ }{
+ {
+ name: "create directory",
+ setup: func() string {
+ return filepath.Join(tempDir, "testdir")
+ },
+ wantError: false,
+ },
+ {
+ name: "existing directory",
+ setup: func() string {
+ dir := filepath.Join(tempDir, "testdir")
+ err := os.Mkdir(dir, 0700)
+ require.NoError(t, err)
+
+ return dir
+ },
+ wantError: false,
+ },
+ {
+ name: "symlink to non-existent directory",
+ setup: func() string {
+ dir := filepath.Join(tempDir, "testdir")
+ symlink := filepath.Join(tempDir, "symlink")
+ err := os.Symlink(dir, symlink)
+ require.NoError(t, err)
+
+ return symlink
+ },
+ wantError: true,
+ },
+ {
+ name: "invalid path",
+ setup: func() string {
+ return string([]byte{0})
+ },
+ wantError: true,
+ },
+ }
+
+ for _, tc := range tests {
+ tc := tc
+ t.Run(tc.name, func(t *testing.T) {
+ dir := tc.setup()
+ defer os.RemoveAll(dir)
+
+ err := CreateDir(dir, 0700)
+ if tc.wantError {
+ require.Error(t, err)
+ return
+ }
+
+ require.NoError(t, err)
+
+ info, err := os.Stat(dir)
+ require.NoError(t, err)
+ require.True(t, info.IsDir())
+ })
+ }
+}