Httpx 0.28.1 Configuration Proxy Header

[Kiupii]

Hello,

I'm working on a project and we use Httpx to make call to an API threw a proxy and we would like to up our version to 0.28.1.

Until version 0.27.2, in Client object, parameter proxies was deprecated but still available. So we use it to make our configuration as it :

class ApiService:
  
    def __int__(*args):
        self._proxy_token = [token]
        headers = httpx.Headers({"X-Goog-Iap-Jwt-Assertion": self._proxy_token})
        proxy = httpx.Proxy(url=f"http://{proxy_url}:80", headers=headers)
        self._proxy = {"http://": proxy, "https://": proxy}
        .......


    def call_api(*args):
       cert = (
            ....
        )
        with httpx.Client(proxies=self._proxy, cert=cert, verify=self._cert) as client:
           # our call

I seen in this post #2879 that, in the new version, the way to make this was to use parameter mount with HTTPTransport object.

import httpx

# instead of
# client = httpx.Client(
#    proxies={"http://": "http://127.0.0.1:80", "https://": "https://127.0.0.1:443"}
# )
# do ...
client = httpx.Client(
   mounts={
       "http://": httpx.HTTPTransport(proxy="http://127.0.0.1:80"),
       "https://": httpx.HTTPTransport(proxy="https://127.0.0.1:443"),
   }
)

But when i am looking into Httpx documentations (for Client or HTTPTransport) or anywhere else, i don't find how to pass my proxy headers with HTTPTransport.

Can anyone enlighten me ?
Thanks in advance.

[agammann]

Both Client(proxy=...) and HTTPTransport(proxy=...) accept an httpx.Proxy object, so you can keep the headers on that object. Since both schemes use the same proxy in your example, you can use a single proxy and keep the TLS configuration on the client:

import httpx
import ssl

ctx = ssl.create_default_context(cafile="ca-bundle.pem")
ctx.load_cert_chain("client-cert.pem", "client-key.pem")

proxy = httpx.Proxy(
    "http://proxy.example:80",
    headers={"X-Goog-Iap-Jwt-Assertion": proxy_token},
)

with httpx.Client(proxy=proxy, verify=ctx) as client:
    # make requests here
    ...

Use your actual CA bundle and client certificate/key paths above. If you need separate routing via mounts, use HTTPTransport(proxy=proxy, verify=ctx) for each mount: mounted transports do not inherit the client's TLS settings. I tested this with HTTPX 0.28.1 against a local HTTPS server requiring a client certificate through a local proxy. TLS authentication succeeded and the proxy received the custom CONNECT header. See Proxy and client certificates.