old_contents: class SaferProxyFix(object):
  """This middleware can be applied to add HTTP proxy support to an
  application that was not designed with HTTP proxies in mind. It
  sets `REMOTE_ADDR`, `HTTP_HOST` from `X-Forwarded` headers.
  If you have more than one proxy server in front of your app, set
  num_proxy_servers accordingly
  
  Do not use this middleware in non-proxy setups for security reasons.
  get_remote_addr will raise an exception if it sees a request that
  does not seem to have enough proxy servers behind it so long as
  detect_misconfiguration is True.
  
  The original values of `REMOTE_ADDR` and `HTTP_HOST` are stored in
  the WSGI environment as `werkzeug.proxy_fix.orig_remote_addr` and
  `werkzeug.proxy_fix.orig_http_host`.
  
  :param app: the WSGI application
  """
  
  def __init__(self, app, num_proxy_servers=1, detect_misconfiguration=False):
    self.app = app
    self.num_proxy_servers = num_proxy_servers
    self.detect_misconfiguration = detect_misconfiguration
  
  def get_remote_addr(self, forwarded_for):
    """Selects the new remote addr from the given list of ips in
    X-Forwarded-For. By default the last one is picked. Specify
    num_proxy_servers=2 to pick the second to last one, and so on.
    """
    if self.detect_misconfiguration and not forwarded_for:
      raise Exception("SaferProxyFix did not detect a proxy server. Do not use this fixer if you are not behind a proxy.")
    if self.detect_misconfiguration and len(forwarded_for) < self.num_proxy_servers:
      raise Exception("SaferProxyFix did not detect enough proxy servers. Check your num_proxy_servers setting.")
    if forwarded_for and len(forwarded_for) >= self.num_proxy_servers:
      return forwarded_for[-1 * self.num_proxy_servers]
  
  def __call__(self, environ, start_response):
    getter = environ.get
    forwarded_proto = getter('HTTP_X_FORWARDED_PROTO', '')
    forwarded_for = getter('HTTP_X_FORWARDED_FOR', '').split(',')
    forwarded_host = getter('HTTP_X_FORWARDED_HOST', '')
    environ.update({
      'werkzeug.proxy_fix.orig_wsgi_url_scheme': getter('wsgi.url_scheme'),
      'werkzeug.proxy_fix.orig_remote_addr': getter('REMOTE_ADDR'),
      'werkzeug.proxy_fix.orig_http_host': getter('HTTP_HOST')
    })
    forwarded_for = [x for x in [x.strip() for x in forwarded_for] if x]
    remote_addr = self.get_remote_addr(forwarded_for)
    if remote_addr is not None:
      environ['REMOTE_ADDR'] = remote_addr
    if forwarded_host:
      environ['HTTP_HOST'] = forwarded_host
    if forwarded_proto:
      environ['wsgi.url_scheme'] = forwarded_proto
    return self.app(environ, start_response)
  
new_contents: class SaferProxyFix(object):
    """This middleware can be applied to add HTTP proxy support to an
    application that was not designed with HTTP proxies in mind. It
    sets `REMOTE_ADDR`, `HTTP_HOST` from `X-Forwarded` headers.
    If you have more than one proxy server in front of your app, set
    num_proxy_servers accordingly
  
    Do not use this middleware in non-proxy setups for security reasons.
    get_remote_addr will raise an exception if it sees a request that
    does not seem to have enough proxy servers behind it so long as
    detect_misconfiguration is True.
  
    The original values of `REMOTE_ADDR` and `HTTP_HOST` are stored in
    the WSGI environment as `werkzeug.proxy_fix.orig_remote_addr` and
    `werkzeug.proxy_fix.orig_http_host`.
  
    :param app: the WSGI application
    """
  
    def __init__(self, app, num_proxy_servers=1, detect_misconfiguration=False):
      self.app = app
      self.num_proxy_servers = num_proxy_servers
      self.detect_misconfiguration = detect_misconfiguration
  
    def get_remote_addr(self, forwarded_for):
      """Selects the new remote addr from the given list of ips in
      X-Forwarded-For. By default the last one is picked. Specify
      num_proxy_servers=2 to pick the second to last one, and so on.
      """
      if self.detect_misconfiguration and not forwarded_for:
        raise Exception("SaferProxyFix did not detect a proxy server. Do not use this fixer if you are not behind a proxy.")
      if self.detect_misconfiguration and len(forwarded_for) < self.num_proxy_servers:
        raise Exception("SaferProxyFix did not detect enough proxy servers. Check your num_proxy_servers setting.")
      if forwarded_for and len(forwarded_for) >= self.num_proxy_servers:
        return forwarded_for[-1 * self.num_proxy_servers]
  
    def __call__(self, environ, start_response):
      getter = environ.get
      forwarded_proto = getter('HTTP_X_FORWARDED_PROTO', '')
      forwarded_for = getter('HTTP_X_FORWARDED_FOR', '').split(',')
      forwarded_host = getter('HTTP_X_FORWARDED_HOST', '')
      environ.update({
        'werkzeug.proxy_fix.orig_wsgi_url_scheme': getter('wsgi.url_scheme'),
        'werkzeug.proxy_fix.orig_remote_addr': getter('REMOTE_ADDR'),
        'werkzeug.proxy_fix.orig_http_host': getter('HTTP_HOST')
      })
      forwarded_for = [x for x in [x.strip() for x in forwarded_for] if x]
      remote_addr = self.get_remote_addr(forwarded_for)
      if remote_addr is not None:
        environ['REMOTE_ADDR'] = remote_addr
      if forwarded_host:
        environ['HTTP_HOST'] = forwarded_host
      if forwarded_proto:
        environ['wsgi.url_scheme'] = forwarded_proto
      return self.app(environ, start_response)
  
subject: Fix ip address