| package opts |
| |
| import ( |
| "bufio" |
| "fmt" |
| "os" |
| "strings" |
| ) |
| |
| // ParseEnvFile reads a file with environment variables enumerated by lines |
| // |
| // ``Environment variable names used by the utilities in the Shell and |
| // Utilities volume of IEEE Std 1003.1-2001 consist solely of uppercase |
| // letters, digits, and the '_' (underscore) from the characters defined in |
| // Portable Character Set and do not begin with a digit. *But*, other |
| // characters may be permitted by an implementation; applications shall |
| // tolerate the presence of such names.'' |
| // -- http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap08.html |
| // |
| // As of #16585, it's up to application inside docker to validate or not |
| // environment variables, that's why we just strip leading whitespace and |
| // nothing more. |
| func ParseEnvFile(filename string) ([]string, error) { |
| fh, err := os.Open(filename) |
| if err != nil { |
| return []string{}, err |
| } |
| defer fh.Close() |
| |
| lines := []string{} |
| scanner := bufio.NewScanner(fh) |
| for scanner.Scan() { |
| // trim the line from all leading whitespace first |
| line := strings.TrimLeft(scanner.Text(), whiteSpaces) |
| // line is not empty, and not starting with '#' |
| if len(line) > 0 && !strings.HasPrefix(line, "#") { |
| data := strings.SplitN(line, "=", 2) |
| |
| // trim the front of a variable, but nothing else |
| variable := strings.TrimLeft(data[0], whiteSpaces) |
| if strings.ContainsAny(variable, whiteSpaces) { |
| return []string{}, ErrBadEnvVariable{fmt.Sprintf("variable '%s' has white spaces", variable)} |
| } |
| |
| if len(data) > 1 { |
| |
| // pass the value through, no trimming |
| lines = append(lines, fmt.Sprintf("%s=%s", variable, data[1])) |
| } else { |
| // if only a pass-through variable is given, clean it up. |
| lines = append(lines, fmt.Sprintf("%s=%s", strings.TrimSpace(line), os.Getenv(line))) |
| } |
| } |
| } |
| return lines, scanner.Err() |
| } |
| |
| var whiteSpaces = " \t" |
| |
| // ErrBadEnvVariable typed error for bad environment variable |
| type ErrBadEnvVariable struct { |
| msg string |
| } |
| |
| func (e ErrBadEnvVariable) Error() string { |
| return fmt.Sprintf("poorly formatted environment: %s", e.msg) |
| } |