Pulsar treats "Date" as a hop-by-hop header

[sekrause]

When I run my Flask app with Pulsar, I get a lot of log warnings like this:

13:28:02 [p=3204, t=4416, WARNING, pulsar.wsgi-worker] Application passing hop header "Date"

I get a new log entry each time Flask serves a static file simply because the reponse includes this header. Looking into pulsar/apps/wsgi/utils.py we can see that Pulsar treats the following header as hop-by-hop headers:

HOP_HEADERS = frozenset(('connection',
                         'keep-alive',
                         'proxy-authenticate',
                         'proxy-authorization',
                         'te',
                         'trailers',
                         'transfer-encoding',
                         'upgrade',
                         'server',
                         'date')
                        )

However, that seems to be in conflict with the official HTTP/1.1 RFC:

The following HTTP/1.1 headers are hop-by-hop headers:

  - Connection
  - Keep-Alive
  - Proxy-Authenticate
  - Proxy-Authorization
  - TE
  - Trailers
  - Transfer-Encoding
  - Upgrade

So server and date should probably be removed from HOP_HEADERS because it is against the spec and because frameworks like Flask which use the Date header will pollute the log file.

[lsbardel]

I'm not sure why Server and Date are there! They shouldn't.