/* * MinIO Cloud Storage, (C) 2018, 2019 MinIO, Inc. * * 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 logger import ( "bytes" "fmt" "io" "net/http" "time" "github.com/gorilla/mux" "github.com/minio/minio/cmd/logger/message/audit" ) // ResponseWriter - is a wrapper to trap the http response status code. type ResponseWriter struct { http.ResponseWriter StatusCode int // Response body should be logged LogBody bool TimeToFirstByte time.Duration StartTime time.Time // number of bytes written bytesWritten int // Internal recording buffer headers bytes.Buffer body bytes.Buffer // Indicate if headers are written in the log headersLogged bool } // NewResponseWriter - returns a wrapped response writer to trap // http status codes for auditiing purposes. func NewResponseWriter(w http.ResponseWriter) *ResponseWriter { return &ResponseWriter{ ResponseWriter: w, StatusCode: http.StatusOK, StartTime: time.Now().UTC(), } } func (lrw *ResponseWriter) Write(p []byte) (int, error) { n, err := lrw.ResponseWriter.Write(p) lrw.bytesWritten += n if lrw.TimeToFirstByte == 0 { lrw.TimeToFirstByte = time.Now().UTC().Sub(lrw.StartTime) } if !lrw.headersLogged { // We assume the response code to be '200 OK' when WriteHeader() is not called, // that way following Golang HTTP response behavior. lrw.writeHeaders(&lrw.headers, http.StatusOK, lrw.Header()) lrw.headersLogged = true } if lrw.StatusCode >= http.StatusBadRequest || lrw.LogBody { // Always logging error responses. lrw.body.Write(p) } if err != nil { return n, err } return n, err } // Write the headers into the given buffer func (lrw *ResponseWriter) writeHeaders(w io.Writer, statusCode int, headers http.Header) { n, _ := fmt.Fprintf(w, "%d %s\n", statusCode, http.StatusText(statusCode)) lrw.bytesWritten += n for k, v := range headers { n, _ := fmt.Fprintf(w, "%s: %s\n", k, v[0]) lrw.bytesWritten += n } } // BodyPlaceHolder returns a dummy body placeholder var BodyPlaceHolder = []byte("") // Body - Return response body. func (lrw *ResponseWriter) Body() []byte { // If there was an error response or body logging is enabled // then we return the body contents if lrw.StatusCode >= http.StatusBadRequest || lrw.LogBody { return lrw.body.Bytes() } // ... otherwise we return the place holder return BodyPlaceHolder } // WriteHeader - writes http status code func (lrw *ResponseWriter) WriteHeader(code int) { lrw.StatusCode = code if !lrw.headersLogged { lrw.writeHeaders(&lrw.headers, code, lrw.ResponseWriter.Header()) lrw.headersLogged = true } lrw.ResponseWriter.WriteHeader(code) } // Flush - Calls the underlying Flush. func (lrw *ResponseWriter) Flush() { lrw.ResponseWriter.(http.Flusher).Flush() } // Size - reutrns the number of bytes written func (lrw *ResponseWriter) Size() int { return lrw.bytesWritten } // AuditTargets is the list of enabled audit loggers var AuditTargets = []Target{} // AddAuditTarget adds a new audit logger target to the // list of enabled loggers func AddAuditTarget(t Target) { AuditTargets = append(AuditTargets, t) } // AuditLog - logs audit logs to all audit targets. func AuditLog(w http.ResponseWriter, r *http.Request, api string, reqClaims map[string]interface{}) { var statusCode int var timeToResponse time.Duration var timeToFirstByte time.Duration lrw, ok := w.(*ResponseWriter) if ok { statusCode = lrw.StatusCode timeToResponse = time.Now().UTC().Sub(lrw.StartTime) timeToFirstByte = lrw.TimeToFirstByte } vars := mux.Vars(r) bucket := vars["bucket"] object := vars["object"] // Send audit logs only to http targets. for _, t := range AuditTargets { entry := audit.ToEntry(w, r, reqClaims, globalDeploymentID) entry.API.Name = api entry.API.Bucket = bucket entry.API.Object = object entry.API.Status = http.StatusText(statusCode) entry.API.StatusCode = statusCode entry.API.TimeToFirstByte = timeToFirstByte.String() entry.API.TimeToResponse = timeToResponse.String() _ = t.Send(entry, string(All)) } }