Request ID Logging (#1087)

* Add RequestID to the RequestScope

* Expose RequestID to auth & request loggers

* Use the RequestID in templated HTML pages

* Allow customizing the RequestID header

* Document new Request ID support

* Add more cases to scope/requestID tests

* Split Get vs Generate RequestID funtionality

* Add {{.RequestID}} to the request logger tests

* Move RequestID management to RequestScope

* Use HTML escape instead of sanitization for Request ID rendering

pkg/apis/middleware/scope.go

@@ -21,6 +21,10 @@ type RequestScope struct {
 	// mode and if request `X-Forwarded-*` headers should be trusted
 	ReverseProxy bool
 
+	// RequestID is set to the request's `X-Request-Id` header if set.
+	// Otherwise a random UUID is set.
+	RequestID string
+
 	// Session details the authenticated users information (if it exists).
 	Session *sessions.SessionState