websocket: Unable to hijack the connection

[yuriy-zhilovets2]

v1.2.0-rc2
v1.2.0

etcd backend on Debian box

Configuration (read from etcd):

etcdctl get /traefik/backends/r-announcer/servers/server41/url
ws://172.25.255.41:2010

etcdctl get /traefik/frontends/r-announcer/passHostHeader
false

etcdctl get /traefik/frontends/r-announcer/backend
r-announcer

etcdctl get /traefik/frontends/r-announcer/entrypoints
https

etcdctl get /traefik/frontends/r-announcer/routes/host/rule
Host:announcer.mol.net.ua

etcdctl get /traefik/entrypoints/https/address
:443

etcdctl get /traefik/entrypoints/https/compress
false

tls settngs skipped because they work with https wihout any problems

time="2017-03-22T21:05:47+03:00" level=debug msg="Creating frontend r-announcer" 
time="2017-03-22T21:05:47+03:00" level=debug msg="Wiring frontend r-announcer to entryPoint http" 
time="2017-03-22T21:05:47+03:00" level=debug msg="Creating route host Host:announcer.mol.net.ua" 
time="2017-03-22T21:05:47+03:00" level=debug msg="Wiring frontend r-announcer to entryPoint https" 
time="2017-03-22T21:05:47+03:00" level=debug msg="Creating route host Host:announcer.mol.net.ua" 
time="2017-03-22T21:05:47+03:00" level=debug msg="Creating backend r-announcer" 
time="2017-03-22T21:05:47+03:00" level=debug msg="Creating load-balancer wrr" 
time="2017-03-22T21:05:47+03:00" level=debug msg="Creating server server41 at ws://172.25.255.41:2010 with weight 0"

The settings for proxiyng web sockets are fairly standard. I have studied thoroughly #452, so there are no:

ddr balancer (on this backend)
circuitbreaker (on this backend)
retry (globally)
compress (on entrypoint https)

But all log is filled with:

Unable to hijack the connection: *negroni.responseWriter the ResponseWriter doesn't support the Hijacker interface

and all connections to frontend URL immediately return 500 without any attempts to call backend.

[thomasf]

I see this problem as well after upgrading to 1.2 from 1.1.2

[emilevauge]

Could give a try without retry and then without circuit breaker ?

[thomasf]

I have none of those enabled if I understand things correctly..

I just have a single back end (the latest offifical pre build mattermost prod docker images) configured via docker compose.

Retry or Compress are not mentioned in my traefik toml config file.

The status page says: 'Load Balancer: wrr'

The labels inside my docker-compose-file:

 labels:
      traefik.backend: mattermost
      traefik.port: "80"
      traefik.frontend.rule: Host:somehost.com
      traefik.docker.network: traefik
      traefik.enable: "true"

[yuriy-zhilovets2]

That's my results without any circuitbreaker and retry is not mentioned in my config.

[Vincoll]

I also encounter this error systematically, causing a 500 error on websockets.
If necessary I can provide details logs and informations for the bug fix.

What version of Traefik are you using?

Version:      v1.2.1
Codename:     morbier
Go version:   go1.7.5
Built:        2017-03-27_03:19:40PM
OS/Arch:      linux/amd64

What is your environment & configuration (arguments, toml...)?

{
 "GraceTimeOut": 10,
 "Debug": false,
 "CheckNewVersion": true,
 "AccessLogsFile": "",
 "TraefikLogsFile": "",
 "LogLevel": "ERROR",
 "EntryPoints": {
  "http": {
   "Network": "",
   "Address": ":80",
   "TLS": null,
   "Redirect": {
    "EntryPoint": "https",
    "Regex": "",
    "Replacement": ""
   },
   "Auth": null,
   "Compress": false
  },
  "https": {
   "Network": "",
   "Address": ":443",
   "TLS": {
    "MinVersion": "",
    "CipherSuites": null,
    "Certificates": [
     {
      "CertFile": "-----BEGIN CERTIFICATE-----[...]-----END CERTIFICATE-----",
      "KeyFile": "-----BEGIN PRIVATE KEY-----[...]-----END PRIVATE KEY-----"
     }
    ],
    "ClientCAFiles": null
   },
   "Redirect": null,
   "Auth": null,
   "Compress": false
  }
 },
 "Cluster": null,
 "Constraints": [],
 "ACME": null,
 "DefaultEntryPoints": [
  "http",
  "https"
 ],
 "ProvidersThrottleDuration": 2000000000,
 "MaxIdleConnsPerHost": 200,
 "InsecureSkipVerify": false,
 "Retry": null,
 "Docker": null,
 "File": null,
 "Web": {
  "Address": ":8080",
  "CertFile": "",
  "KeyFile": "",
  "ReadOnly": false,
  "Statistics": {
   "RecentErrors": 50
  },
  "Metrics": null,
  "Auth": {
   "Basic": {
    "Users": [
     "[...]:[...]"
    ]
   },
   "Digest": null,
   "HeaderField": ""
  }
 },
 "Marathon": null,
 "Consul": null,
 "ConsulCatalog": null,
 "Etcd": null,
 "Zookeeper": null,
 "Boltdb": null,
 "Kubernetes": null,
 "Mesos": null,
 "Eureka": null,
 "ECS": null,
 "Rancher": {
  "Watch": true,
  "Filename": "",
  "Constraints": null,
  "Endpoint": "",
  "AccessKey": "",
  "SecretKey": "",
  "ExposedByDefault": false,
  "Domain": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 },
 "ConfigFile": "/etc/traefik/traefik.toml"
}

[krohrsb]

Similar problem.

time="2017-04-09T00:37:07Z" level=info msg="Traefik version v1.2.1 built on 2017-03-27_03:19:40PM"

Using docker.

I've got a container specifying a label traefik.frontend.entryPoints=https,wss

https works fine, just the trouble with websockets.

[Ranger-X]

Try to turn off detailed statistics (subsection [web.statistics] in [web]). Unexpected, but it helped me.

[yuriy-zhilovets2]

Unbelievable but true. Turning off the statistics fixes the error. Thank you, Ranger-X.

[Vincoll]

I confirm too. WS are OK now.
Thank you !

[emilevauge]

Hum, thanks for this investigation @Ranger-X.
We need to add this to StatsRecorder:

var (
	_ http.ResponseWriter = &StatsRecorder{}
	_ http.Hijacker       = &StatsRecorder{}
	_ http.Flusher        = &StatsRecorder{}
	_ http.CloseNotifier  = &StatsRecorder{}
)

[phoenix741]

I have the same problem, if i comment this two line like this :

#  [web.statistics]
#  RecentErrors = 10

The problem is resolved too.

[ldez]

Closed by #1598