werkzeug.middleware.proxy_fix.ProxyFix

class documentation

class ProxyFix:

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Adjust the WSGI environ based on X-Forwarded- that proxies in front of the application may set.

  • X-Forwarded-For sets REMOTE_ADDR.
  • X-Forwarded-Proto sets wsgi.url_scheme.
  • X-Forwarded-Host sets HTTP_HOST, SERVER_NAME, and SERVER_PORT.
  • X-Forwarded-Port sets HTTP_HOST and SERVER_PORT.
  • X-Forwarded-Prefix sets SCRIPT_NAME.

You must tell the middleware how many proxies set each header so it knows what values to trust. It is a security issue to trust values that came from the client rather than a proxy.

The original values of the headers are stored in the WSGI environ as werkzeug.proxy_fix.orig, a dict.

from werkzeug.middleware.proxy_fix import ProxyFix
# App is behind one proxy that sets the -For and -Host headers.
app = ProxyFix(app, x_for=1, x_host=1)

Changed in version 1.0: Deprecated code has been removed:

  • The num_proxies argument and attribute.
  • The get_remote_addr method.
  • The environ keys orig_remote_addr, orig_wsgi_url_scheme, and orig_http_host.
Changed in version 0.15: All headers support multiple values. The num_proxies argument is deprecated. Each header is configured with a separate number of trusted proxies.
Changed in version 0.15: Original WSGI environ values are stored in the werkzeug.proxy_fix.orig dict. orig_remote_addr, orig_wsgi_url_scheme, and orig_http_host are deprecated and will be removed in 1.0.
Changed in version 0.15: Support X-Forwarded-Port and X-Forwarded-Prefix.
Changed in version 0.15: X-Forwarded-Host and X-Forwarded-Port modify SERVER_NAME and SERVER_PORT.
Parameters
appThe WSGI application to wrap.
x​_forNumber of values to trust for X-Forwarded-For.
x​_protoNumber of values to trust for X-Forwarded-Proto.
x​_hostNumber of values to trust for X-Forwarded-Host.
x​_portNumber of values to trust for X-Forwarded-Port.
x​_prefixNumber of values to trust for X-Forwarded-Prefix.
Method __call__ Modify the WSGI environ based on the various Forwarded headers before calling the wrapped application. Store the original environ values in werkzeug.proxy_fix.orig_{key}.
Method __init__ Undocumented
Instance Variable app Undocumented
Instance Variable x​_for Undocumented
Instance Variable x​_host Undocumented
Instance Variable x​_port Undocumented
Instance Variable x​_prefix Undocumented
Instance Variable x​_proto Undocumented
Method ​_get​_real​_value Get the real value from a list header based on the configured number of trusted proxies.
def __call__(self, environ, start_response):
Modify the WSGI environ based on the various Forwarded headers before calling the wrapped application. Store the original environ values in werkzeug.proxy_fix.orig_{key}.
Parameters
environ:WSGIEnvironmentUndocumented
start​_response:StartResponseUndocumented
Returns
t.Iterable[bytes]Undocumented
def __init__(self, app, x_for=1, x_proto=1, x_host=0, x_port=0, x_prefix=0):

Undocumented

Parameters
app:WSGIApplicationUndocumented
x​_for:intUndocumented
x​_proto:intUndocumented
x​_host:intUndocumented
x​_port:intUndocumented
x​_prefix:intUndocumented
app =

Undocumented

x_for =

Undocumented

x_host =

Undocumented

x_port =

Undocumented

x_prefix =

Undocumented

x_proto =

Undocumented

def _get_real_value(self, trusted, value):

Get the real value from a list header based on the configured number of trusted proxies.

Changed in version 1.0: Renamed from _get_trusted_comma.
New in version 0.15.
Parameters
trusted:intNumber of values to trust in the header.
value:t.Optional[str]Comma separated list header value to parse.
Returns
t.Optional[str]The real value, or None if there are fewer values than the number of trusted proxies.