all: use helper funcs for ctx's tracking info

Also use a bool for DoNotTrack, since the value stored in it is never
used.

And simplify the DoNotTrack logic, since it only sets the vars to their
original values.

For TykTechnologies#683.

api.go

@@ -1863,3 +1863,25 @@ func ctxSetAuthToken(r *http.Request, t string) {
 	}
 	context.Set(r, AuthHeaderValue, t)
 }
+
+func ctxGetTrackedPath(r *http.Request) string {
+	if v := context.Get(r, TrackThisEndpoint); v != nil {
+		return v.(string)
+	}
+	return ""
+}
+
+func ctxSetTrackedPath(r *http.Request, p string) {
+	if p == "" {
+		panic("setting a nil context TrackThisEndpoint")
+	}
+	context.Set(r, TrackThisEndpoint, p)
+}
+
+func ctxGetDoNotTrack(r *http.Request) bool {
+	return context.Get(r, DoNotTrackThisEndpoint) == true
+}
+
+func ctxSetDoNotTrack(r *http.Request, b bool) {
+	context.Set(r, DoNotTrackThisEndpoint, b)
+}

handler_error.go

@@ -122,17 +122,11 @@ func (e *ErrorHandler) HandleError(w http.ResponseWriter, r *http.Request, errMs
 			rawRequest = base64.StdEncoding.EncodeToString(wireFormatReq.Bytes())
 		}
 
-		trackThisEndpoint := context.Get(r, TrackThisEndpoint)
-		trackedPath := r.URL.Path
 		trackEP := false
-		if trackThisEndpoint != nil {
+		trackedPath := r.URL.Path
+		if p := ctxGetTrackedPath(r); p != "" && !ctxGetDoNotTrack(r) {
 			trackEP = true
-			trackedPath = trackThisEndpoint.(string)
-		}
-
-		if context.Get(r, DoNotTrackThisEndpoint) != nil {
-			trackEP = false
-			trackedPath = r.URL.Path
+			trackedPath = p
 		}
 
 		record := AnalyticsRecord{

handler_success.go

@@ -245,17 +245,11 @@ func (s *SuccessHandler) RecordHit(r *http.Request, timing int64, code int, requ
 			rawResponse = base64.StdEncoding.EncodeToString(wireFormatRes.Bytes())
 		}
 
-		trackThisEndpoint := context.Get(r, TrackThisEndpoint)
-		trackedPath := r.URL.Path
 		trackEP := false
-		if trackThisEndpoint != nil {
+		trackedPath := r.URL.Path
+		if p := ctxGetTrackedPath(r); p != "" && !ctxGetDoNotTrack(r) {
 			trackEP = true
-			trackedPath = trackThisEndpoint.(string)
-		}
-
-		if context.Get(r, DoNotTrackThisEndpoint) != nil {
-			trackEP = false
-			trackedPath = r.URL.Path
+			trackedPath = p
 		}
 
 		record := AnalyticsRecord{

middleware_track_endpoints.go

@@ -3,8 +3,6 @@ package main
 import (
 	"net/http"
 
-	"github.com/gorilla/context"
-
 	"github.com/TykTechnologies/tyk/apidef"
 )
 
@@ -32,12 +30,12 @@ func (a *TrackEndpointMiddleware) ProcessRequest(w http.ResponseWriter, r *http.
 	_, versionPaths, _, _ := a.TykMiddleware.Spec.GetVersionData(r)
 	foundTracked, metaTrack := a.TykMiddleware.Spec.CheckSpecMatchesStatus(r.URL.Path, r.Method, versionPaths, RequestTracked)
 	if foundTracked {
-		context.Set(r, TrackThisEndpoint, metaTrack.(*apidef.TrackEndpointMeta).Path)
+		ctxSetTrackedPath(r, metaTrack.(*apidef.TrackEndpointMeta).Path)
 	}
 
-	foundDnTrack, meta_dnTrack := a.TykMiddleware.Spec.CheckSpecMatchesStatus(r.URL.Path, r.Method, versionPaths, RequestNotTracked)
+	foundDnTrack, _ := a.TykMiddleware.Spec.CheckSpecMatchesStatus(r.URL.Path, r.Method, versionPaths, RequestNotTracked)
 	if foundDnTrack {
-		context.Set(r, DoNotTrackThisEndpoint, meta_dnTrack.(*apidef.TrackEndpointMeta).Path)
+		ctxSetDoNotTrack(r, true)
 	}
 
 	return nil, 200