package dockerignore // import "github.com/docker/docker/builder/dockerignore" import ( "bufio" "bytes" "fmt" "io" "path/filepath" "strings" ) // ReadAll reads a .dockerignore file and returns the list of file patterns // to ignore. Note this will trim whitespace from each line as well // as use GO's "clean" func to get the shortest/cleanest path for each. func ReadAll(reader io.Reader) ([]string, error) { if reader == nil { return nil, nil } scanner := bufio.NewScanner(reader) var excludes []string currentLine := 0 utf8bom := []byte{0xEF, 0xBB, 0xBF} for scanner.Scan() { scannedBytes := scanner.Bytes() // We trim UTF8 BOM if currentLine == 0 { scannedBytes = bytes.TrimPrefix(scannedBytes, utf8bom) } pattern := string(scannedBytes) currentLine++ // Lines starting with # (comments) are ignored before processing if strings.HasPrefix(pattern, "#") { continue } pattern = strings.TrimSpace(pattern) if pattern == "" { continue } // normalize absolute paths to paths relative to the context // (taking care of '!' prefix) invert := pattern[0] == '!' if invert { pattern = strings.TrimSpace(pattern[1:]) } if len(pattern) > 0 { pattern = filepath.Clean(pattern) pattern = filepath.ToSlash(pattern) if len(pattern) > 1 && pattern[0] == '/' { pattern = pattern[1:] } } if invert { pattern = "!" + pattern } excludes = append(excludes, pattern) } if err := scanner.Err(); err != nil { return nil, fmt.Errorf("Error reading .dockerignore: %v", err) } return excludes, nil }