| package dockerfile2llb |
| |
| import ( |
| "bufio" |
| "io" |
| "regexp" |
| "strings" |
| ) |
| |
| const keySyntax = "syntax" |
| |
| var reDirective = regexp.MustCompile(`^#\s*([a-zA-Z][a-zA-Z0-9]*)\s*=\s*(.+?)\s*$`) |
| |
| func DetectSyntax(r io.Reader) (string, string, bool) { |
| directives := ParseDirectives(r) |
| if len(directives) == 0 { |
| return "", "", false |
| } |
| v, ok := directives[keySyntax] |
| if !ok { |
| return "", "", false |
| } |
| p := strings.SplitN(v, " ", 2) |
| return p[0], v, true |
| } |
| |
| func ParseDirectives(r io.Reader) map[string]string { |
| m := map[string]string{} |
| s := bufio.NewScanner(r) |
| for s.Scan() { |
| match := reDirective.FindStringSubmatch(s.Text()) |
| if len(match) == 0 { |
| return m |
| } |
| m[strings.ToLower(match[1])] = match[2] |
| } |
| return m |
| } |
