`ethstats` plug-in fails with HTTP error 504 if not given full URI

• trinity version: trinity-v0.1.0-alpha.16-15-g3eb6dc5d (current master: commit 3eb6dc5d7e755ec96fc65df1833b9c3628990ab2)
• OS: Arch Linux
• Python Version (python --version): 3.7.0
• Environment (output of pip freeze): MISSING

What is wrong?

PR #1336 squash-merged work from PR #1216, implementing the ethstats plug-in.

I’ve tried it with an actual “secret token” I have for wss://ropsten-stats.parity.io/, and there’s always a 504 when trying to connect via WebSocket:

   ERROR  09-29 23:36:59       EthstatsService  Unexpected error in <trinity.plugins.builtin.ethstats.ethstats_service.EthstatsService object at 0x7f4ac6dafa58>, exiting
Traceback (most recent call last):                                                                     
  File "/home/veox/src/py-evm/p2p/service.py", line 103, in run                                        
    await self._run()                                                                                  
  File "/home/veox/src/py-evm/trinity/plugins/builtin/ethstats/ethstats_service.py", line 68, in _run  
    async with websockets.connect(self.server_url) as websocket:                                       
  File "/home/veox/src/py-evm/.virtualenv/py-evm/lib/python3.7/site-packages/websockets/py35/client.py", line 2, in __aenter__
    return await self                                                                                  
  File "/home/veox/src/py-evm/.virtualenv/py-evm/lib/python3.7/site-packages/websockets/py35/client.py", line 19, in __await_impl__
    extra_headers=protocol.extra_headers,                                                              
  File "/home/veox/src/py-evm/.virtualenv/py-evm/lib/python3.7/site-packages/websockets/client.py", line 263, in handshake
    raise InvalidStatusCode(status_code)                                                               
websockets.exceptions.InvalidStatusCode: Status code not 101: 504                                      
Traceback (most recent call last):                                                                     
  File "/home/veox/src/py-evm/p2p/service.py", line 103, in run                                        
    await self._run()                                                                                  
  File "/home/veox/src/py-evm/trinity/plugins/builtin/ethstats/ethstats_service.py", line 68, in _run  
    async with websockets.connect(self.server_url) as websocket:                                       
  File "/home/veox/src/py-evm/.virtualenv/py-evm/lib/python3.7/site-packages/websockets/py35/client.py", line 2, in __aenter__
    return await self                                                                                  
  File "/home/veox/src/py-evm/.virtualenv/py-evm/lib/python3.7/site-packages/websockets/py35/client.py", line 19, in __await_impl__
    extra_headers=protocol.extra_headers,
  File "/home/veox/src/py-evm/.virtualenv/py-evm/lib/python3.7/site-packages/websockets/client.py", line 263, in handshake
    raise InvalidStatusCode(status_code)
websockets.exceptions.InvalidStatusCode: Status code not 101: 504

EDIT: As a sanity check, I’ve tried with my previous setup of jsonrpcproxy+eth-net-intelligence-api, and it still works. So the URL/secret are correct.

How can it be fixed

See comment.

Either:

• add api to the URL in the plug-in ourselves; or
• instruct the user (in docs?) to specify the full endpoint path and rename “URL” to “URI”.

[pipermerriam]

Also, I think that we can auto select a default for the URI if the node is running against ropsten/mainnet or really any network ID for which we know the right default URI.

[evgeniuz]

Tried to test this with SSL enabled, but it works for me.

@veox BTW, if you pass wss://ropsten-stats.parity.io/ as server URL, can you please try passing wss://ropsten-stats.parity.io/api, as that is endpoint clients should connect to.