Update KibanaRequest to use the new WHATWG URL API

[watson]

This PR is a prerequisite for upgrading to hapi v18.

The reason for this is that the new version of hapi uses the WHATWG URL format for its request.url property instead of the legacy url format.

Note to reviewers

The hack of using request._core.info.uri to build the new URL object, isn't needed once we upgrade to hapi v18, as this version of hapi already uses the WHATWG URL API. So instead of constructing the URL object once the KibanaRequest is instantiated, we simply copy it from the hapi request object.

Note to future self

If you remove the urlCopy hack in src/core/server/http/lifecycle/on_pre_routing.ts, you can reproduce the problem it's trying to fix by first performing the following cURL request:

curl \
  -X GET \
  -u elastic:changeme "localhost:5601/s/space_1/api/saved_objects/dashboard/cts_dashboard" \
  -H 'kbn-xsrf: true'

This will prime the process and put it in a state where the error will occur in the next request, which you perform with the following cURL request:

curl \
  -X GET \
  -u elastic:changeme "localhost:5601/api/saved_objects/dashboard/cts_dashboard" \
  -H 'kbn-xsrf: true'

The first cURL request will trigger the request.setUrl line in src/core/server/http/lifecycle/on_pre_routing.ts, which will screw up the internal object holding the routing table in such a way that the call router used by hapi can't find the saved_objects segment under api and will make the request fall through to the catch-all route.

The only thing needed from this PR to trigger the bug, is the following in src/core/server/http/router/request.ts:

-    this.url = request.url;
+    this.url = new URL(request.url.href!, request._core.info.uri);

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

[nchaulet]

Ingest manager changes 🚀

[mshustov]

I'm glad I didn't have to debug this 😄

[gmmorris]

LGTM for Alerts, TaskManager & EventLog 👍

[azasypkin]

ACK: will review the security team related changes today or tomorrow morning at the latest.

[thomheymann]

LGTM 👍

[jgowdyelastic]

ML changes LGTM

[thomheymann]

Awesome, looks good!

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: f648288

Metrics [docs]

✅ unchanged

History

• 💔 Build #84259 failed e13886a
• 💚 Build #83866 succeeded 7cb51c2
• 💚 Build #83750 succeeded 4180378
• 💚 Build #83722 succeeded 0a2ad8a
• 💔 Build #82743 failed 6aa7526

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

[azasypkin]

Security/Spaces changes LGTM, thanks!