Update Unzip to retain previous signature to avoid breaking external …

…usage

Make filesToUnzip a glob of remaining arguments and set default if the argument has not been provided

Issue #315

lib/files.go

@@ -45,9 +45,17 @@ func CheckFileExist(file string) bool {
 
 // Unzip will decompress a zip archive, moving all files and folders
 // within the zip file (parameter 1) to an output directory (parameter 2).
-func Unzip(src string, dest string, fileToUnzip string) ([]string, error) {
+// fileToUnzip (parameter 3) specifices the file within the zipfile to be extracted.
+// This is optional and default to "terraform"
+func Unzip(src string, dest string, fileToUnzipSlice ...string) ([]string, error) {
 	logger.Debugf("Unzipping file %q", src)
 
+	// Handle old signature of method, where fileToUnzip did not exist
+	fileToUnzip := "terraform"
+	if len(fileToUnzipSlice) > 0 {
+		fileToUnzip = fileToUnzipSlice[0]
+	}
+
 	var filenames []string
 
 	reader, err := zip.OpenReader(src)
@@ -79,9 +87,9 @@ func Unzip(src string, dest string, fileToUnzip string) ([]string, error) {
 	unzipWaitGroup.Wait()
 
 	if len(filenames) < 1 {
-		logger.Fatalf("Could not find terraform file in release archive to unzip")
+		logger.Fatalf("Could not find %s file in release archive to unzip", fileToUnzipSlice[])
 	} else if len(filenames) > 1 {
-		logger.Fatalf("Extracted more files than expected in release archive")
+		logger.Fatal("Extracted more files than expected in release archive")
 	}
 
 	return filenames, nil