Extract t8n arguments from daemon query string

[SamWilsn]

What was wrong?

Closes #1029
Closes #1006

How was it fixed?

This commit allows daemon clients to pass command line arguments in the query string (under the key arg.) To add multiple arguments, use multiple key/value pairs. For example:

curl --unix-socket /run/user/1000/ethereum-spec-evm/daemon.sock 'http://localhost/?arg=--help'

curl --unix-socket /run/user/1000/ethereum-spec-evm/daemon.sock 'http://localhost/?arg=--help&arg=--state-test'

Cute Animal Picture

[SamWilsn]

This is paired with petertdavies/ethereum-spec-evm-resolver#5

[marioevz]

It seems to be working when passing a single parameter as "?key=--state-test" for example, but when passing none is complaining with the following error:

Exception occurred during processing of request from ['local', 0]                                                                    
Traceback (most recent call last):                                                                                                   
  File "/usr/lib/python3.10/socketserver.py", line 316, in _handle_request_noblock                                                   
    self.process_request(request, client_address)                                                                                    
  File "/usr/lib/python3.10/socketserver.py", line 347, in process_request                                                           
    self.finish_request(request, client_address)                                                                                     
  File "/home/marioevz/.cache/ethereum-spec-evm-resolver/Cancun/src/ethereum_spec_tools/evm_tools/daemon.py", line 100, in finish_req
uest                                                                                                                                 
    super().finish_request(request, client_address)                                                                                  
  File "/usr/lib/python3.10/socketserver.py", line 360, in finish_request                                                            
    self.RequestHandlerClass(request, client_address, self)                                                                          
  File "/usr/lib/python3.10/socketserver.py", line 747, in __init__                                                                  
    self.handle()                                                                                                                      File "/usr/lib/python3.10/http/server.py", line 433, in handle                                                                     
    self.handle_one_request()                                                                                                        
  File "/usr/lib/python3.10/http/server.py", line 421, in handle_one_request                                                         
    method()                                                                                                                         
  File "/home/marioevz/.cache/ethereum-spec-evm-resolver/Cancun/src/ethereum_spec_tools/evm_tools/daemon.py", line 62, in do_POST    
    query = parse_qs(                                                                                                                
  File "/usr/lib/python3.10/urllib/parse.py", line 714, in parse_qs                                                                  
    pairs = parse_qsl(qs, keep_blank_values, strict_parsing,                                                                         
  File "/usr/lib/python3.10/urllib/parse.py", line 775, in parse_qsl                                                                 
    raise ValueError("bad query field: %r" % (name_value,))                                                                          
ValueError: bad query field: ''

I'm debugging to see if I can find the issue, I tried passing empty string and "?" but same behavior.

[SamWilsn]

What's the full URL you're using?

[marioevz]

What's the full URL you're using?

This is an example I obtained from the resolver right before sending the query:
With --state-test:

http+unix://%2Ftmp%2Ftmp5975ll06%2FCancun.3885864.sock/?arg=--state-test

Without --state-test:

http+unix://%2Ftmp%2Ftmpjshog8l0%2FCancun.3886038.sock/

[marioevz]

I reproduced locally and it seems like parse_qs complains if the result from urlparse(self.path).query is an empty string, which is the case if no arguments are passed.

It's a weird behavior from parse_qs IMO, but the easiest solution seems to be to skip the query parsing altogether in the case that urlparse(self.path).query is an empty string.

I tested locally and it seems to work, but let me know what you think.

[SamWilsn]

That's really odd. Only thing I can think of is that I'm in Python 3.12, and maybe they changed the behaviour? Pushed a fix; let me know if it works for you.

[marioevz]

LGTM.

Last change seems to have fixed my issue, thanks!