Set network_userid to empty UUID in anonymous mode to prevent collector_payload_format_violation

[paulboocock]

When anonymous tracking is enabled in the JavaScript Tracker, as of version 2.1.2 we set the network_user to an empty string, which leads to collector_payload_format_violation errors downstream due to "" being an invalid UUID.

JavaScript Tracker (v2.17.3) example:

  <script type="text/javascript" async=1>
    ; (function (p, l, o, w, i, n, g) {
      if (!p[i]) {
        p.GlobalSnowplowNamespace = p.GlobalSnowplowNamespace || [];
        p.GlobalSnowplowNamespace.push(i); p[i] = function () {
          (p[i].q = p[i].q || []).push(arguments)
        }; p[i].q = p[i].q || []; n = l.createElement(o); g = l.getElementsByTagName(o)[0]; n.async = 1;
        n.src = w; g.parentNode.insertBefore(n, g)
      }
    }(window, document, "script", "https://cdn.jsdelivr.net/gh/snowplow/[email protected]/sp.js", "snowplow"));
  </script>

  <script>
    window.snowplow('newTracker', 'sp1', '{{COLLECTOR_URL}}', {
      appId: 'simple-test-1'
    });

    window.snowplow('enableAnonymousTracking', { withServerAnonymisation: true });
    window.snowplow('trackPageView');
  </script>

should have a network_userid of 00000000-0000-0000-0000-000000000000.

[dilyand]

Hey @paulboocock , this looks good. However I feel that it's unnecessarily late to swap the nuid with a dummy value when we're building the event. To me it seems more appropriate to do it when we're extracting the nuid from the request / cookie here: https://github.com/snowplow/stream-collector/blob/master/core/src/main/scala/com.snowplowanalytics.snowplow.collectors.scalastream/CollectorService.scala#L115.

This can be achieved with a change in the networkUserId function: https://github.com/snowplow/stream-collector/blob/master/core/src/main/scala/com.snowplowanalytics.snowplow.collectors.scalastream/CollectorService.scala#L460

def networkUserId(
    request: HttpRequest,
    requestCookie: Option[HttpCookie],
    spAnonymous: Option[String]
  ): Option[String] =
    spAnonymous match {
      case Some(_) => request.uri.query().get("nuid").orElse(requestCookie.map(_.value))
      case None    => Some("00000000-0000-0000-0000-000000000000")
    }

WDYT?

[paulboocock]

That seems reasonable, keeps the nuid "calculatation" in the right function. The only reason I put it so far down the chain was so we didn't accidentally write a nuid when we shouldn't in the future but with some good unit tests this is likely not much of a risk.

[dilyand]

Closing in favour of #124.