Be able to force the client information

To be able to generate correct URL when we debug with pserve behind a
reverse proxy.

README.md

@@ -670,7 +670,7 @@ A few other environment variables can be used to tune the info sent with each re
 
 # Developer info
 
-You will need `docker` (>=1.12.0), `docker-compose` (>=1.10.0) and
+You will need `docker` (>=1.12.0), `docker compose` and
 `make` installed on the machine to play with this project.
 Check available versions of `docker-engine` with
 `apt-get policy docker-engine` and eventually force install the
@@ -699,6 +699,13 @@ To make a release:
 - Add the new branch name in the `.github/workflows/rebuild.yaml` and
   `.github/workflows/audit.yaml` files.
 
+## Pserve
+
+Pserve will not set the headers in the environment then if you are behind a reverse proxy, you will have
+wrong values in client information, you can force them by using the environment variables:
+`C2CWSGIUTILS_FORCE_PROTO`, `C2CWSGIUTILS_FORCE_HOST` `C2CWSGIUTILS_FORCE_SERVER_NAME` and
+`C2CWSGIUTILS_FORCE_REMOTE_ADDR`.
+
 ## Testing
 
 ### Screenshots

c2cwsgiutils/client_info.py

@@ -1,3 +1,4 @@
+import os
 import re
 from typing import Any, Callable
 
@@ -22,6 +23,15 @@ def __call__(self, environ: dict[str, str], start_response: Any) -> Any:
         else:
             _handle_others(environ)
 
+        if "C2CWSGIUTILS_FORCE_PROTO" in os.environ:
+            os.environ["wsgi.url_scheme"] = os.environ.pop("C2CWSGIUTILS_FORCE_PROTO")
+        if "C2CWSGIUTILS_FORCE_HOST" in os.environ:
+            os.environ["HTTP_HOST"] = os.environ.pop("C2CWSGIUTILS_FORCE_HOST")
+        if "C2CWSGIUTILS_FORCE_SERVER_NAME" in os.environ:
+            os.environ["SERVER_NAME"] = os.environ.pop("C2CWSGIUTILS_FORCE_SERVER_NAME")
+        if "C2CWSGIUTILS_FORCE_REMOTE_ADDR" in os.environ:
+            os.environ["REMOTE_ADDR"] = os.environ.pop("C2CWSGIUTILS_FORCE_REMOTE_ADDR")
+
         return self._application(environ, start_response)