"no router to route request" (regex_priority is nil)

[mars]

For Kong version 1.0.0-1.0.2 configured with a Route with null/nil regex_priority, Kong throws a 500 error when receiving any request, logging the error (formatted for readability):

2019/01/28 22:47:06 [error] 54#0: *33046 [kong] handler.lua:687
  no router to route request (reason:
    /app/kong-runtime/share/lua/5.1/kong/runloop/handler.lua:116:
      attempt to compare nil with number), 
  client: x.x.x.x, 
  server: kong, 
  request: "GET /favicon.ico HTTP/1.1", 
  host: "xxxxx.example.com", 
  referrer: "https://xxxxx.example.com/"

Looking at Kong source location referenced in that error:

    sort(routes, function(r1, r2)
      r1, r2 = r1.route, r2.route
      if r1.regex_priority == r2.regex_priority then
        return r1.created_at < r2.created_at
      end
      return r1.regex_priority > r2.regex_priority  -- ← THIS IS LINE #116
    end)

So it seems to be routing code comparing route priorities.

I check the Postgres database to see what the route contains for that field:

-[ RECORD 2 ]--+-------------------------------------
id             | b4e8ae92-8e4c-40a4-87d9-98af04969da0
created_at     | 2019-01-28 23:07:05+00
updated_at     | 2019-01-28 23:07:05+00
service_id     | 36a43882-84ba-4fc8-aa2a-94569c4bf2b7
protocols      | {https}
methods        | 
hosts          | {mars-micro-wasabi.happ.host}
paths          | 
regex_priority |                                      ← THIS FIELD IS NULL
strip_path     | t
preserve_host  | f
name           | 
snis           | 
sources        | 
destinations   | 

The field is null.

So, it seems like at least one of these solutions would be good for Kong:

• that handler/routing code should gracefully accept nil (treat like 0)
• the data access layer should fill in a default of 0
• the API should reject Route configuration requests that contain "regex_priority": null

[thibaultcha]

@mars Thanks for the report! I can provide a patch asap.

[thibaultcha]

@mars Btw, a Route's default regex_priority is 0 (as can be seen in its schema). How did you have this field set to NULL? An update, or a PUT maybe?

[thibaultcha]

PR is #4255 - feel free to apply the patch on your end and verify that it solves the issue for you. Thanks again!

[mars]

Amazing! Thank you @thibaultcha I will build Kong on that PR and reply here with results.

My requests that set regex_priority → nil are from kevholditch/terraform-provider-kong, updating via PATCH & creating via POST.

[mars]

Using the PR's "fix/router-rebuild-no-regex-priority" branch I built Kong and while the 500 error is gone, it no longer matches requests for the route at all:

{"message":"no Route matched with those values"}

This route used to work, but have yet to discover why it's not matching now:

resource "kong_route" "wasabi_hostname" {
  protocols  = ["https"]
  paths      = ["/wasabi"]
  strip_path = true
  service_id = "${kong_service.wasabi.id}"
}

Will continue debugging tomorrow.

[mars]

Now that the fix has been merged to master, I built Kong from master and now see that this is fixed ✅ 💯 Thank you for the fast action @thibaultcha 🤗

[forestgagnon]

FYI for those running Kong EE: I discovered that this bug is still present in some of the route-building logic in the latest enterprise edition (0.35-3). I've submitted a support ticket about this.