/*
Wraps the given http.Handler ServerHTTP function
Will provide accounting metrics for the http.Request / http.Response life-cycle
*/
func (ih *instrumentedHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
requestId, err := uuid.ParseHex(req.Header.Get("X-CF-RequestID"))
if err != nil {
requestId, err = GenerateUuid()
if err != nil {
log.Printf("failed to generated request ID: %v\n", err)
requestId = &uuid.UUID{}
}
req.Header.Set("X-CF-RequestID", requestId.String())
}
rw.Header().Set("X-CF-RequestID", requestId.String())
startEvent := factories.NewHttpStart(req, events.PeerType_Server, requestId)
err = ih.emitter.Emit(startEvent)
if err != nil {
log.Printf("failed to emit start event: %v\n", err)
}
instrumentedWriter := &instrumentedResponseWriter{writer: rw, statusCode: 200}
ih.handler.ServeHTTP(instrumentedWriter, req)
stopEvent := factories.NewHttpStop(req, instrumentedWriter.statusCode, instrumentedWriter.contentLength, events.PeerType_Server, requestId)
err = ih.emitter.Emit(stopEvent)
if err != nil {
log.Printf("failed to emit stop event: %v\n", err)
}
}
/*
Wraps the RoundTrip function of the given RoundTripper.
Will provide accounting metrics for the http.Request / http.Response life-cycle
Callers of RoundTrip are responsible for setting the ‘X-CF-RequestID’ field in the request header if they have one.
Callers are also responsible for setting the ‘X-CF-ApplicationID’ and ‘X-CF-InstanceIndex’ fields in the request header if they are known.
*/
func (irt *instrumentedRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
requestId, err := GenerateUuid()
if err != nil {
log.Printf("failed to generated request ID: %v\n", err)
requestId = &uuid.UUID{}
}
httpStart := factories.NewHttpStart(req, events.PeerType_Client, requestId)
parentRequestId, err := uuid.ParseHex(req.Header.Get("X-CF-RequestID"))
if err == nil {
httpStart.ParentRequestId = factories.NewUUID(parentRequestId)
}
req.Header.Set("X-CF-RequestID", requestId.String())
err = irt.emitter.Emit(httpStart)
if err != nil {
log.Printf("failed to emit start event: %v\n", err)
}
resp, roundTripErr := irt.roundTripper.RoundTrip(req)
var httpStop *events.HttpStop
if roundTripErr != nil {
httpStop = factories.NewHttpStop(req, 0, 0, events.PeerType_Client, requestId)
} else {
httpStop = factories.NewHttpStop(req, resp.StatusCode, resp.ContentLength, events.PeerType_Client, requestId)
}
err = irt.emitter.Emit(httpStop)
if err != nil {
log.Printf("failed to emit stop event: %v\n", err)
}
return resp, roundTripErr
}
Describe("NewHttpStart", func() {
Context("without an application ID or instanceIndex", func() {
It("should set appropriate fields", func() {
expectedStartEvent := &events.HttpStart{
RequestId: factories.NewUUID(requestId),
PeerType: events.PeerType_Server.Enum(),
Method: events.HttpStart_GET.Enum(),
Uri: proto.String("foo.example.com/"),
RemoteAddress: proto.String("127.0.0.1"),
UserAgent: proto.String("our-testing-client"),
}
startEvent := factories.NewHttpStart(req, events.PeerType_Server, requestId)
Expect(startEvent.GetTimestamp()).ToNot(BeZero())
startEvent.Timestamp = nil
Expect(startEvent).To(Equal(expectedStartEvent))
})
})
Context("with an application ID", func() {
It("should include it in the start event", func() {
applicationId, _ := uuid.NewV4()
req.Header.Set("X-CF-ApplicationID", applicationId.String())
startEvent := factories.NewHttpStart(req, events.PeerType_Server, requestId)