package utils import ( "encoding/json" "fmt" "io" "net/http" "net/url" "os" "strings" "github.com/blang/semver" "github.com/gorilla/mux" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) type ( // VersionTree determines which API endpoint tree for version VersionTree int // VersionLevel determines which API level, current or something from the past VersionLevel int ) const ( // LibpodTree supports Libpod endpoints LibpodTree = VersionTree(iota) // CompatTree supports Libpod endpoints CompatTree // CurrentAPIVersion announces what is the current API level CurrentAPIVersion = VersionLevel(iota) // MinimalAPIVersion announces what is the oldest API level supported MinimalAPIVersion ) var ( // See https://docs.docker.com/engine/api/v1.40/ // libpod compat handlers are expected to honor docker API versions // APIVersion provides the current and minimal API versions for compat and libpod endpoint trees // Note: GET|HEAD /_ping is never versioned and provides the API-Version and Libpod-API-Version headers to allow // clients to shop for the Version they wish to support APIVersion = map[VersionTree]map[VersionLevel]semver.Version{ LibpodTree: { CurrentAPIVersion: semver.MustParse("1.0.0"), MinimalAPIVersion: semver.MustParse("1.0.0"), }, CompatTree: { CurrentAPIVersion: semver.MustParse("1.40.0"), MinimalAPIVersion: semver.MustParse("1.24.0"), }, } // 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, errors.Wrapf(err, "unable to unescape given API version: %q", val) } version, err = semver.ParseTolerant(safeVal) if err != nil { return version, errors.Wrapf(err, "unable to parse given API version: %q from %q", safeVal, val) } 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 := CompatTree if IsLibpodRequest(r) { tree = LibpodTree } return SupportedVersion(r, fmt.Sprintf(">=%s <=%s", APIVersion[tree][MinimalAPIVersion].String(), APIVersion[tree][CurrentAPIVersion].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 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(errors.Wrapf(err, "failed to unescape mux key %s, value %s", k, val)) return val } return safeVal } // GetName extracts the name from the mux func GetName(r *http.Request) string { return getVar(r, "name") }