/*
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)
}
}
func createEnvelope(eventType events.Envelope_EventType) *events.Envelope {
envelope := &events.Envelope{Origin: proto.String("origin"), EventType: &eventType, Timestamp: proto.Int64(time.Now().UnixNano())}
switch eventType {
case events.Envelope_HttpStart:
req, _ := http.NewRequest("GET", "http://www.example.com", nil)
req.RemoteAddr = "www.example.com"
req.Header.Add("User-Agent", "user-agent")
uuid, _ := uuid.NewV4()
envelope.HttpStart = factories.NewHttpStart(req, events.PeerType_Client, uuid)
case events.Envelope_HttpStop:
req, _ := http.NewRequest("GET", "http://www.example.com", nil)
uuid, _ := uuid.NewV4()
envelope.HttpStop = factories.NewHttpStop(req, http.StatusOK, 128, events.PeerType_Client, uuid)
case events.Envelope_HttpStartStop:
req, _ := http.NewRequest("GET", "http://www.example.com", nil)
req.RemoteAddr = "www.example.com"
req.Header.Add("User-Agent", "user-agent")
uuid, _ := uuid.NewV4()
envelope.HttpStartStop = factories.NewHttpStartStop(req, http.StatusOK, 128, events.PeerType_Client, uuid)
case events.Envelope_ValueMetric:
envelope.ValueMetric = factories.NewValueMetric("some-value-metric", 123, "km")
case events.Envelope_CounterEvent:
envelope.CounterEvent = factories.NewCounterEvent("some-counter-event", 123)
case events.Envelope_LogMessage:
envelope.LogMessage = factories.NewLogMessage(events.LogMessage_OUT, "some message", "appId", "source")
case events.Envelope_ContainerMetric:
envelope.ContainerMetric = factories.NewContainerMetric("appID", 123, 1, 5, 5)
case events.Envelope_Error:
envelope.Error = factories.NewError("source", 123, "message")
default:
fmt.Printf("Unknown event %v\n", eventType)
return nil
}
return envelope
}
/*
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
}
}
message, err := proto.Marshal(containerMetric)
Expect(err).ToNot(HaveOccurred())
_, err = unmarshaller.UnmarshallMessage(message)
Expect(err).ToNot(HaveOccurred())
Eventually(func() uint64 { return fakeSender.GetCounter("dropsondeUnmarshaller.containerMetricReceived") }).Should(BeEquivalentTo(1))
})
It("HTTP start event", func() {
uuid, _ := uuid.NewV4()
request, _ := http.NewRequest("GET", "https://example.com", nil)
httpStart := &events.Envelope{
Origin: proto.String("origin"),
EventType: events.Envelope_HttpStart.Enum(),
HttpStart: factories.NewHttpStart(request, events.PeerType_Client, uuid),
}
message, err := proto.Marshal(httpStart)
Expect(err).ToNot(HaveOccurred())
_, err = unmarshaller.UnmarshallMessage(message)
Expect(err).ToNot(HaveOccurred())
Eventually(func() uint64 { return fakeSender.GetCounter("dropsondeUnmarshaller.httpStartReceived") }).Should(BeEquivalentTo(1))
})
It("HTTP stop event", func() {
uuid, _ := uuid.NewV4()
request, _ := http.NewRequest("GET", "https://example.com", nil)
httpStop := &events.Envelope{
Origin: proto.String("origin"),
EventType: events.Envelope_HttpStop.Enum(),
HttpStop: factories.NewHttpStop(request, 200, 567, events.PeerType_Client, uuid),
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.Method_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)