Probe websocket double-connect/disconnect

[bboreham]

I added some more logging to app/controls.go:

@@ -95,9 +96,10 @@ func handleProbeWS(cr ControlRouter) CtxHandlerFunc {
                        respondWith(ctx, w, http.StatusBadRequest, err)
                        return
                }
+               log.Infof("Registered probe %s (%d)", probeID, id)
                defer cr.Deregister(ctx, probeID, id)
-               if err := codec.WaitForReadError(); err != nil && !xfer.IsExpectedWSCloseError(err) {
-                       log.Errorf("Error on websocket: %v", err)
+               if err := codec.WaitForReadError(); err != nil /*&& !xfer.IsExpectedWSCloseError(err)*/ {
+                       log.Errorf("Error on websocket from probe %s (%d): %v", probeID, id, err)
                }
        }
 }

and observed this pattern, where different probes disconnect (that's what error 1006 means) then reconnect twice in quick succession:

<app> INFO: 2021/05/18 10:55:12.128837 app starting, version dacfd66e, ID 250f6a02c6baf2f7
<app> INFO: 2021/05/18 10:55:12.128883 command line args: --app.http.address=:80 --mode=app --weave=false
<app> INFO: 2021/05/18 10:55:12.129327 Basic authentication disabled
<app> INFO: 2021/05/18 10:55:12.129467 listening on :80
<app> INFO: 2021/05/18 10:55:13.107251 Registered probe 7776b1e8bdfca2d2 (2389263251951777280)
<app> INFO: 2021/05/18 10:55:13.110027 Registered probe 6c9c4562da09a115 (8839232576504565880)
<app> INFO: 2021/05/18 10:55:13.111379 Registered probe 301c3075165d128d (4509635939760995389)
<app> INFO: 2021/05/18 10:55:13.111448 Registered probe 63cc85218ecf4fd5 (2096114807635611025)
<app> INFO: 2021/05/18 10:55:13.115702 Registered probe 70a1351b675f3949 (1081430012913752367)
<app> INFO: 2021/05/18 10:55:13.115929 Registered probe 5bb63ea0a20a3666 (963780891770807684)
<app> INFO: 2021/05/18 10:55:13.123519 Registered probe 929c2321520af1f (262033173521075032)
<app> INFO: 2021/05/18 10:55:14.109107 Registered probe 22c8b8a2f66f5574 (8775167029614101706)
<app> INFO: 2021/05/18 10:55:14.111184 Registered probe 5eaa20ad7d7e2cae (6380512523209295092)
<app> ERRO: 2021/05/18 10:55:16.518348 Error on websocket from probe 70a1351b675f3949 (1081430012913752367): websocket: close 1006 (abnormal closure): unexpected EOF
<app> INFO: 2021/05/18 10:55:16.518950 Registered probe 70a1351b675f3949 (6950709212411960207)
<app> INFO: 2021/05/18 10:55:16.518980 Registered probe 70a1351b675f3949 (1044548149924223819)
<app> ERRO: 2021/05/18 10:55:16.519344 Error on websocket from probe 70a1351b675f3949 (6950709212411960207): websocket: close 1006 (abnormal closure): unexpected EOF
<app> ERRO: 2021/05/18 10:55:36.237923 Error on websocket from probe 22c8b8a2f66f5574 (8775167029614101706): websocket: close 1006 (abnormal closure): unexpected EOF
<app> INFO: 2021/05/18 10:55:36.242291 Registered probe 22c8b8a2f66f5574 (2841541895986255109)
<app> INFO: 2021/05/18 10:55:36.436206 Registered probe 22c8b8a2f66f5574 (1836450431459227589)
<app> ERRO: 2021/05/18 10:55:36.436618 Error on websocket from probe 22c8b8a2f66f5574 (1836450431459227589): websocket: close 1006 (abnormal closure): unexpected EOF
<app> ERRO: 2021/05/18 10:55:51.341544 Error on websocket from probe 7776b1e8bdfca2d2 (2389263251951777280): websocket: close 1006 (abnormal closure): unexpected EOF
<app> INFO: 2021/05/18 10:55:51.342401 Registered probe 7776b1e8bdfca2d2 (249717423108416770)
<app> INFO: 2021/05/18 10:55:51.342401 Registered probe 7776b1e8bdfca2d2 (3743738419699173713)
<app> ERRO: 2021/05/18 10:55:51.342765 Error on websocket from probe 7776b1e8bdfca2d2 (3743738419699173713): websocket: close 1006 (abnormal closure): unexpected EOF
<app> INFO: 2021/05/18 10:56:02.506321 Registered probe 6c9c4562da09a115 (7854952504722763749)
<app> INFO: 2021/05/18 10:56:02.507742 Registered probe 6c9c4562da09a115 (2175365361958449149)
<app> ERRO: 2021/05/18 10:56:02.509808 Error on websocket from probe 6c9c4562da09a115 (7854952504722763749): websocket: close 1006 (abnormal closure): unexpected EOF
<app> ERRO: 2021/05/18 10:56:02.510059 Error on websocket from probe 6c9c4562da09a115 (8839232576504565880): websocket: close 1006 (abnormal closure): unexpected EOF