package utils import ( "errors" "fmt" "io" "net/http" "net/url" "os" "strings" "unsafe" "github.com/blang/semver" "github.com/containers/podman/v4/version" "github.com/gorilla/mux" jsoniter "github.com/json-iterator/go" "github.com/sirupsen/logrus" ) var ( // ErrVersionNotGiven returned when version not given by client ErrVersionNotGiven = errors.New("version not given in URL path") // ErrVersionNotSupported returned when given version is too old ErrVersionNotSupported = errors.New("given version is not supported") ) // IsLibpodRequest returns true if the request related to a libpod endpoint // (e.g., /v2/libpod/...). func IsLibpodRequest(r *http.Request) bool { split := strings.Split(r.URL.String(), "/") return len(split) >= 3 && split[2] == "libpod" } // SupportedVersion validates that the version provided by client is included in the given condition // https://github.com/blang/semver#ranges provides the details for writing conditions // If a version is not given in URL path, ErrVersionNotGiven is returned func SupportedVersion(r *http.Request, condition string) (semver.Version, error) { version := semver.Version{} val, ok := mux.Vars(r)["version"] if !ok { return version, ErrVersionNotGiven } safeVal, err := url.PathUnescape(val) if err != nil { return version, fmt.Errorf("unable to unescape given API version: %q: %w", val, err) } version, err = semver.ParseTolerant(safeVal) if err != nil { return version, fmt.Errorf("unable to parse given API version: %q from %q: %w", safeVal, val, err) } inRange, err := semver.ParseRange(condition) if err != nil { return version, err } if inRange(version) { return version, nil } return version, ErrVersionNotSupported } // SupportedVersionWithDefaults validates that the version provided by client valid is supported by server // minimal API version <= client path version <= maximum API version focused on the endpoint tree from URL func SupportedVersionWithDefaults(r *http.Request) (semver.Version, error) { tree := version.Compat if IsLibpodRequest(r) { tree = version.Libpod } return SupportedVersion(r, fmt.Sprintf(">=%s <=%s", version.APIVersion[tree][version.MinimalAPI].String(), version.APIVersion[tree][version.CurrentAPI].String())) } // WriteResponse encodes the given value as JSON or string and renders it for http client func WriteResponse(w http.ResponseWriter, code int, value interface{}) { // RFC2616 explicitly states that the following status codes "MUST NOT // include a message-body": switch code { case http.StatusNoContent, http.StatusNotModified: // 204, 304 w.WriteHeader(code) return } switch v := value.(type) { case string: w.Header().Set("Content-Type", "text/plain; charset=us-ascii") w.WriteHeader(code) if _, err := fmt.Fprintln(w, v); err != nil { logrus.Errorf("Unable to send string response: %q", err) } case *os.File: w.Header().Set("Content-Type", "application/octet; charset=us-ascii") w.WriteHeader(code) if _, err := io.Copy(w, v); err != nil { logrus.Errorf("Unable to copy to response: %q", err) } case io.Reader: w.Header().Set("Content-Type", "application/x-tar") w.WriteHeader(code) if _, err := io.Copy(w, v); err != nil { logrus.Errorf("Unable to copy to response: %q", err) } default: WriteJSON(w, code, value) } } func init() { jsoniter.RegisterTypeEncoderFunc("error", MarshalErrorJSON, MarshalErrorJSONIsEmpty) jsoniter.RegisterTypeEncoderFunc("[]error", MarshalErrorSliceJSON, MarshalErrorSliceJSONIsEmpty) } var json = jsoniter.ConfigCompatibleWithStandardLibrary // MarshalErrorJSON writes error to stream as string func MarshalErrorJSON(ptr unsafe.Pointer, stream *jsoniter.Stream) { p := *((*error)(ptr)) if p == nil { stream.WriteNil() } else { stream.WriteString(p.Error()) } } // MarshalErrorSliceJSON writes []error to stream as []string JSON blob func MarshalErrorSliceJSON(ptr unsafe.Pointer, stream *jsoniter.Stream) { a := *((*[]error)(ptr)) switch { case len(a) == 0: stream.WriteNil() default: stream.WriteArrayStart() for i, e := range a { if i > 0 { stream.WriteMore() } stream.WriteString(e.Error()) } stream.WriteArrayEnd() } } func MarshalErrorJSONIsEmpty(ptr unsafe.Pointer) bool { return *((*error)(ptr)) == nil } func MarshalErrorSliceJSONIsEmpty(ptr unsafe.Pointer) bool { return len(*((*[]error)(ptr))) == 0 } // WriteJSON writes an interface value encoded as JSON to w func WriteJSON(w http.ResponseWriter, code int, value interface{}) { // FIXME: we don't need to write the header in all/some circumstances. w.Header().Set("Content-Type", "application/json") w.WriteHeader(code) coder := json.NewEncoder(w) coder.SetEscapeHTML(true) if err := coder.Encode(value); err != nil { logrus.Errorf("Unable to write json: %q", err) } } func FilterMapToString(filters map[string][]string) (string, error) { f, err := json.Marshal(filters) if err != nil { return "", err } return string(f), nil } func GetVar(r *http.Request, k string) string { val := mux.Vars(r)[k] safeVal, err := url.PathUnescape(val) if err != nil { logrus.Error(fmt.Errorf("failed to unescape mux key %s, value %s: %w", k, val, err)) return val } return safeVal } // GetName extracts the name from the mux func GetName(r *http.Request) string { return GetVar(r, "name") }