[Plugin] How to parameterize?

[deeplook]

I'm looking for ways to parameterize custom plugins. In my case I want to write one that acts like a "man in the middle" who some value to the HTTP header before passing on the request. Is there some recommended pattern? So far I have something like this, which is not ideal:

from typing import Optional
from proxy.http.parser import HttpParser
from proxy.http.proxy import HttpProxyBasePlugin

class ModifyHeaderPlugin(HttpProxyBasePlugin):
    """Modify request header before sending to upstream server."""

    # This seems not to be a working pattern:
    # def __init__(self, headers: Optional[dict] = None, **kwargs):
    #     self.added_headers = headers or {}
    #     # HttpProxyBasePlugin.__init__(self, **kwargs)

    def before_upstream_connection(self, request: HttpParser) -> Optional[HttpParser]:
        return request

    def handle_client_request(self, request: HttpParser) -> Optional[HttpParser]:
        # I'd prefer to pass this token to the constructor:
        request.add_header(b'Authorization', bytes(f"Bearer {token}", "utf-8"))
        return request

    def handle_upstream_chunk(self, chunk: memoryview) -> memoryview:
        return chunk

    def on_upstream_connection_close(self) -> None:
        pass

[abhinavsingh]

@deeplook Apologies first of all for missing all your discussions. I'll get to your other threads shortly.

proxy.py plugins can have their own flags. See https://github.com/abhinavsingh/proxy.py/blob/develop/proxy/plugin/filter_by_client_ip.py#L20. Let me know if this doesn't help.

[abhinavsingh]

    def handle_client_request(self, request: HttpParser) -> Optional[HttpParser]:
        # I'd prefer to pass this token to the constructor:
        request.add_header(b'Authorization', bytes(f"Bearer {token}", "utf-8"))
        return request

If the token here is static i.e. same for all outgoing requests, then flags will simply do the trick. You can define a flag like:

flags.add_argument(
    '--bearer-token',
    type=str,
    default=None,
    help='Default: None.  Bearer token.'
)

Then you can use this flag within the plugin as:

self.flags.bearer_token

If the token itself is dynamic, then it will be best to dynamically fetch the token from within the plugin when necessary.

I hope this helps.