How to filter a request for a host with mitmproxy addon if its hostname match a regex?

Question

I wanna implement an addon which filters and remove all request for a set of domains. All domains must match with the following regex:

a-.+\.xxxx\.com

I do not know how to get a request hostname:

if re.match("a-.+\.xxxx\.com", flow.request.hostname):
     # Do something

Answer 1

In the mitmproxy, the following class is used to encapsulate request information:

mitmproxy.net.http.Request

And the contractor of the Request class is:

def __init__(
        self,
        host: str,
        port: int,
        method: bytes,
        scheme: bytes,
        authority: bytes,
        path: bytes,
        http_version: bytes,
        headers: Union[Headers, Tuple[Tuple[bytes, bytes], ...]],
        content: Optional[bytes],
        trailers: Union[None, Headers, Tuple[Tuple[bytes, bytes], ...]],
        timestamp_start: float,
        timestamp_end: Optional[float],
):

So, somewhere in the platform the host and port is passed to the class instance.

The implementation uses a data class to store data:

@dataclass
class RequestData(message.MessageData):
    host: str
    port: int
    method: bytes
    scheme: bytes
    authority: bytes
    path: bytes

Therefor, to access the request hostname:

if re.match("a-.+\.xxxx\.com", flow.request.data.host):
     # Do something

---

Following method added directly into the Request class:

A getter

@property
def host(self) -> str:

A setter

@host.setter
def host(self, val: Union[str, bytes]) -> None:

So the following code is acceptable too:

if re.match("a-.+\.xxxx\.com", flow.request.host):
     # Do something