clair/utils/http/http.go
2016-02-24 16:32:21 -05:00

78 lines
2.6 KiB
Go

// Copyright 2015 clair authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package http provides utility functions for HTTP servers and clients.
package http
import (
"encoding/json"
"io"
"net/http"
"github.com/coreos/clair/database"
"github.com/coreos/clair/utils"
cerrors "github.com/coreos/clair/utils/errors"
"github.com/coreos/clair/worker"
)
// MaxBodySize is the maximum number of bytes that ParseHTTPBody reads from an http.Request.Body.
const MaxBodySize int64 = 1048576
// WriteHTTP writes a JSON-encoded object to a http.ResponseWriter, as well as
// a HTTP status code.
func WriteHTTP(w http.ResponseWriter, httpStatus int, v interface{}) {
w.WriteHeader(httpStatus)
if v != nil {
w.Header().Set("Content-Type", "application/json; charset=utf-8")
result, _ := json.Marshal(v)
w.Write(result)
}
}
// WriteHTTPError writes an error, wrapped in the Message field of a JSON-encoded
// object to a http.ResponseWriter, as well as a HTTP status code.
// If the status code is 0, handleError tries to guess the proper HTTP status
// code from the error type.
func WriteHTTPError(w http.ResponseWriter, httpStatus int, err error) {
if httpStatus == 0 {
httpStatus = http.StatusInternalServerError
// Try to guess the http status code from the error type
if _, isBadRequestError := err.(*cerrors.ErrBadRequest); isBadRequestError {
httpStatus = http.StatusBadRequest
} else {
switch err {
case cerrors.ErrNotFound:
httpStatus = http.StatusNotFound
case database.ErrBackendException:
httpStatus = http.StatusServiceUnavailable
case worker.ErrParentUnknown, worker.ErrUnsupported, utils.ErrCouldNotExtract, utils.ErrExtractedFileTooBig:
httpStatus = http.StatusBadRequest
}
}
}
WriteHTTP(w, httpStatus, struct{ Message string }{Message: err.Error()})
}
// ParseHTTPBody reads a JSON-encoded body from a http.Request and unmarshals it
// into the provided object.
func ParseHTTPBody(r *http.Request, v interface{}) (int, error) {
defer r.Body.Close()
err := json.NewDecoder(io.LimitReader(r.Body, MaxBodySize)).Decode(v)
if err != nil {
return http.StatusUnsupportedMediaType, err
}
return 0, nil
}