feat: Create target dir if it does not exist (#79)

pkg/install/install.go

@@ -77,9 +77,8 @@ func Install(logger logrus.FieldLogger) error {
 		return err
 	}
 
-	// Place the new binaries if the directory is writeable.
-	if err := fileutil.IsDirWriteable(c.CredentialProviderTargetDir); err != nil {
-		return fmt.Errorf("directory is not writeable: %w", err)
+	if err := ensureDirExists(c.CredentialProviderTargetDir); err != nil {
+		return fmt.Errorf("failed to ensure target directory exists and is writable: %w", err)
 	}
 
 	// Iterate through each binary we might want to install.
@@ -112,6 +111,21 @@ func Install(logger logrus.FieldLogger) error {
 	return nil
 }
 
+func ensureDirExists(dir string) error {
+	// Create the directory if it does not already exist.
+	//nolint:revive // 755 is easy to understand file permissions.
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return fmt.Errorf("failed to create target directory: %w", err)
+	}
+
+	// Ensure the directory is writeable.
+	if err := fileutil.IsDirWriteable(dir); err != nil {
+		return fmt.Errorf("directory is not writeable: %w", err)
+	}
+
+	return nil
+}
+
 // copyFileAndPermissions copies file permission.
 func copyFileAndPermissions(src, dst string, logger logrus.FieldLogger) error {
 	// If the source and destination are the same, we can simply return.

pkg/install/install_test.go

@@ -81,6 +81,31 @@ func TestSuccessfulCopy(t *testing.T) {
 	}
 }
 
+func TestSuccessfulCopyNonExistentTarget(t *testing.T) {
+	tmpDir := t.TempDir()
+	targetDir := filepath.Join(tmpDir, "nonexistent")
+
+	t.Setenv(install.CredentialProviderSourceDirEnvVar, "testdata")
+	t.Setenv(install.CredentialProviderTargetDirEnvVar, targetDir)
+
+	require.NoError(t, install.Install(logrus.New()))
+
+	testFiles, err := os.ReadDir("testdata")
+	require.NoError(t, err)
+
+	for _, f := range testFiles {
+		expectedFile := filepath.Join(targetDir, f.Name())
+		assert.FileExists(t, expectedFile)
+		srcFile := filepath.Join("testdata", f.Name())
+		srcFileStat, err := os.Stat(srcFile)
+		assert.NoError(t, err)
+		expectedFileStat, err := os.Stat(expectedFile)
+		assert.NoError(t, err)
+		assert.Equal(t, srcFileStat.Mode(), expectedFileStat.Mode())
+		assertFileHashesEqual(t, srcFile, expectedFile)
+	}
+}
+
 func TestSuccessfulCopySkipFile(t *testing.T) {
 	tmpDir := t.TempDir()