Error 403/forbidden on trying to connect from remote

[Roman-jj]

Hi, when trying to connect to the simulator using the python API, I'm getting an error that I guess could have to do with system proxies again.

On one machine I have the simulator running fine in Unity, WebUI ist working correctly on port 8080, and I can connect to my rosbridge on a remote machine.
Now I installed the python API on the remote machine and tried to connect to the simulator running an API only simulation, but I only get error 403.

For debugging I tried to open a websocket through a python shell and I get the following output:
>>> soc=lgsvl.remote.Remote('53.63.112.62',8081) Exception in thread Thread-8: Traceback (most recent call last): File "/usr/lib/python3.6/threading.py", line 916, in _bootstrap_inner self.run() File "/lhome/joerger/GIT/PythonAPI/lgsvl/remote.py", line 28, in run self.loop.run_until_complete(self.process()) File "/usr/lib/python3.6/asyncio/base_events.py", line 484, in run_until_complete return future.result() File "/lhome/joerger/GIT/PythonAPI/lgsvl/remote.py", line 36, in process self.websocket = await websockets.connect(self.endpoint, compression=None) File "/lhome/joerger/.local/lib/python3.6/site-packages/websockets/py35/client.py", line 20, in __await_impl__ extra_headers=protocol.extra_headers, File "/lhome/joerger/.local/lib/python3.6/site-packages/websockets/client.py", line 286, in handshake raise InvalidStatusCode(status_code) websockets.exceptions.InvalidStatusCode: Status code not 101: 403
and then after interrupt
^CTraceback (most recent call last): File "<stdin>", line 1, in <module> File "/lhome/joerger/GIT/PythonAPI/lgsvl/remote.py", line 23, in __init__ self.sem.acquire() File "/usr/lib/python3.6/threading.py", line 426, in acquire self._cond.wait(timeout) File "/usr/lib/python3.6/threading.py", line 295, in wait waiter.acquire() KeyboardInterrupt

Currently I can't try this on the local machine since python3 is not installed, but when I try to open localhost:8081 in a browser I get 403 forbidden as well.

Could there be any other issue than the proxy settings?

Thanks in advance

[Roman-jj]

Sorry, realized it's port 8181 and not 8081.

I think the problem is a combination of proxy and firewall issues, as I can't even ping the machine running the simulation...
Will leave this open until I've fixed it though

[Roman-jj]

Tried to run a few more tests and it seems it's another proxy problem with python/websockets/...

Connecting locally (localhost) works without problems.
When trying to connect from a remote machine I get the following error:
`>>> sim=lgsvl.Simulator('53.58.82.31',8181)
Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib/python3.6/threading.py", line 916, in _bootstrap_inner
self.run()
File "/lhome/joerger/GIT/PythonAPI/lgsvl/remote.py", line 28, in run
self.loop.run_until_complete(self.process())
File "/usr/lib/python3.6/asyncio/base_events.py", line 484, in run_until_complete
return future.result()
File "/lhome/joerger/GIT/PythonAPI/lgsvl/remote.py", line 36, in process
self.websocket = await websockets.connect(self.endpoint, compression=None)
File "/lhome/joerger/.local/lib/python3.6/site-packages/websockets/client.py", line 537, in await_impl
transport, protocol = await self._create_connection()
File "/usr/lib/python3.6/asyncio/base_events.py", line 794, in create_connection
raise exceptions[0]
File "/usr/lib/python3.6/asyncio/base_events.py", line 781, in create_connection
yield from self.sock_connect(sock, address)
File "/usr/lib/python3.6/asyncio/selector_events.py", line 439, in sock_connect
return (yield from fut)
File "/usr/lib/python3.6/asyncio/selector_events.py", line 469, in _sock_connect_cb
raise OSError(err, 'Connect call failed %s' % (address,))
ConnectionRefusedError: [Errno 111] Connect call failed ('53.58.82.31', 8181)

^CTraceback (most recent call last):
File "", line 1, in
File "/lhome/joerger/GIT/PythonAPI/lgsvl/utils.py", line 21, in new_f
return f(*args, **kwargs)
File "/lhome/joerger/GIT/PythonAPI/lgsvl/simulator.py", line 26, in init
self.remote = Remote(address, port)
File "/lhome/joerger/GIT/PythonAPI/lgsvl/remote.py", line 23, in init
self.sem.acquire()
File "/usr/lib/python3.6/threading.py", line 426, in acquire
self._cond.wait(timeout)
File "/usr/lib/python3.6/threading.py", line 295, in wait
waiter.acquire()
KeyboardInterrupt`

I then tried to connect using the python websocket-client package and got this error:
>>> ws=websocket.create_connection('ws://53.58.82.31:8181') Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/lhome/joerger/.local/lib/python3.6/site-packages/websocket/_core.py", line 514, in create_connection websock.connect(url, **options) File "/lhome/joerger/.local/lib/python3.6/site-packages/websocket/_core.py", line 223, in connect options.pop('socket', None)) File "/lhome/joerger/.local/lib/python3.6/site-packages/websocket/_http.py", line 122, in connect sock = _tunnel(sock, hostname, port, auth) File "/lhome/joerger/.local/lib/python3.6/site-packages/websocket/_http.py", line 293, in _tunnel "failed CONNECT via proxy status: %r" % status) websocket._exceptions.WebSocketProxyException: failed CONNECT via proxy status: 504
Same error when giving proxy server as parameter (ws=websocket.create_connection('ws://53.58.82.31:8181', http_proxy_host="localhost", http_proxy_port=3128))

On the machine with the simulator, I had sudo tcpdump -v -nS dst port 8181 running and got the following output:
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes 10:35:09.589369 IP (tos 0x0, ttl 63, id 64789, offset 0, flags [DF], proto TCP (6), length 60) 53.58.83.77.53108 > 53.58.82.31.8181: Flags [S], cksum 0xba4f (correct), seq 4242272123, win 29200, options [mss 1460,sackOK,TS val 2884862986 ecr 0,nop,wscale 7], length 0 10:47:05.349041 IP (tos 0x0, ttl 63, id 25541, offset 0, flags [DF], proto TCP (6), length 60) 53.58.83.77.53270 > 53.58.82.31.8181: Flags [S], cksum 0x37e2 (correct), seq 3548229295, win 29200, options [mss 1460,sackOK,TS val 2885578741 ecr 0,nop,wscale 7], length 0 10:47:05.349447 IP (tos 0x0, ttl 63, id 48477, offset 0, flags [DF], proto TCP (6), length 60) 53.58.83.77.53272 > 53.58.82.31.8181: Flags [S], cksum 0x7196 (correct), seq 3627970615, win 29200, options [mss 1460,sackOK,TS val 2885578742 ecr 0,nop,wscale 7], length 0 11:05:09.198766 IP (tos 0x0, ttl 58, id 15032, offset 0, flags [DF], proto TCP (6), length 60) 53.55.11.194.25480 > 53.58.82.31.8181: Flags [S], cksum 0xb3f3 (correct), seq 1748941974, win 12288, options [mss 1460,nop,wscale 6,sackOK,TS val 2478071732 ecr 0], length 0 11:10:52.745063 IP (tos 0x0, ttl 58, id 22891, offset 0, flags [DF], proto TCP (6), length 60) 53.55.11.194.35648 > 53.58.82.31.8181: Flags [S], cksum 0xffa9 (correct), seq 4074602639, win 12288, options [mss 1460,nop,wscale 6,sackOK,TS val 2478415272 ecr 0], length 0 11:12:56.912545 IP (tos 0x0, ttl 58, id 57516, offset 0, flags [DF], proto TCP (6), length 60) 53.55.11.194.39411 > 53.58.82.31.8181: Flags [S], cksum 0x3cbe (correct), seq 4184557870, win 12288, options [mss 1460,nop,wscale 6,sackOK,TS val 2478539442 ecr 0], length 0
When I connect from localhost, there is no output in tcpdump.

Working locally for now, but am grateful for any help

[lemketron]

This is an old issue but in case it's still an issue or someone else finds this issue, please refer to the recommendations in this related LGSVL simulator issue.