Enable HTTP/1.1 support for roundup-server

This enables keepalives and seems to prevent a lot of hangs/slowness
in my configuration.

configuration.py: add new HttpVersionOption. This is used by the
    command line/config in roundup-server. Validates http version
    string.

roundup-server.py: enable HTTP 1.1 by default. use -V to set HTTP/1.0
    on command line or set http_version in config file.

    Fix typo in config description for option include_headers.

    Add more vertical spacing for error report and usage display.

roundup-server.1: add doc on -V also doc -I which was missing. Remove
    uneeded "to" from a sentence on ssl.

Author: rouilj

CHANGES.txt

@@ -48,6 +48,10 @@ Features:
   responsive templates already have this feature.
 - issue2550917 - Add a: "Welcome user, you have logged in" ok_message
   on login. (Ashley Burke)
+- enable HTTP/1.1 for roundup-server. This enables keep-alive for
+  faster response/loading. Also eliminates stalls when the front end web
+  server uses http 1.1 but the roundup-server uses 1.0. New option
+  "-V HTTP/1.0" can turn it off. (John Rouillard)
 
 2021-07-13 2.1.0
 

roundup/configuration.py

@@ -639,6 +639,16 @@ def str2value(self, value):
         return value
 
 
+class HttpVersionOption(Option):
+    """Used by roundup-server to verify http version is set to valid
+       string."""
+
+    def str2value(self, value):
+        if value not in ["HTTP/1.0", "HTTP/1.1"]:
+            raise OptionValueError(self, value, "Valid vaues for -V or --http_version are: HTTP/1.0, HTTP/1.1")
+        return value
+
+
 class RegExpOption(Option):
 
     """Regular Expression option (value is Regular Expression Object)"""

roundup/scripts/roundup_server.py

@@ -635,9 +635,12 @@ class ServerConfig(configuration.Config):
             (configuration.WordListOption, "include_headers", "",
                 "Comma separated list of extra headers that should\n"
                 "be copied into the CGI environment.\n"
-                "E.G. if you want to acces the REMOTE_USER and\n"
+                "E.G. if you want to access the REMOTE_USER and\n"
                 "X-Proxy-User headers in the back end,\n"
                 "set to the value REMOTE_USER,X-Proxy-User."),
+            (configuration.HttpVersionOption, "http_version", "HTTP/1.1",
+                "Change to HTTP/1.0 if needed. This disables keepalive."),
+
         )),
         ("trackers", (), "Roundup trackers to serve.\n"
             "Each option in this section defines single Roundup tracker.\n"
@@ -663,6 +666,7 @@ class ServerConfig(configuration.Config):
         "ssl": "s",
         "pem": "e:",
         "include_headers": "I:",
+        "http_version": 'V:',
     }
 
     def __init__(self, config_file=None):
@@ -732,6 +736,8 @@ def setup(self):
                     # internal state correctly so that later closing SSL
                     # socket works (with SSL end-handshake started)
                     self.request.do_handshake()
+                RoundupRequestHandler.protocol_version = \
+                                         self.CONFIG["HTTP_VERSION"]
                 RoundupRequestHandler.setup(self)
 
             def finish(self):
@@ -864,8 +870,8 @@ def usage(message=''):
                to the file indicated by PIDfile. The -l option *must* be
                specified if -d is used.'''
     if message:
-        message += '\n'
-    print(_('''%(message)sUsage: roundup-server [options] [name=tracker home]*
+        message += '\n\n'
+    print(_('''\n%(message)sUsage: roundup-server [options] [name=tracker home]*
 
 Options:
  -v            print the Roundup version number and exit
@@ -886,6 +892,9 @@ def usage(message=''):
  -e <fname>    PEM file containing SSL key and certificate
  -t <mode>     multiprocess mode (default: %(mp_def)s).
                Allowed values: %(mp_types)s.
+ -V <version>  set HTTP version (default: HTTP/1.1).
+               Allowed values: HTTP/1.0, HTTP/1.1.
+
 %(os_part)s
 
 Long options:

share/man/man1/roundup-server.1

@@ -35,8 +35,15 @@ Sets a filename to use as a template for generating the tracker index page.
 The variable "trackers" is available to the template and is a dict of all
 configured trackers.
 .TP
+\fB-I\fP \fIheader1[,header2,...]\fP
+Pass the header(s) and their values to the backend. This allow-list
+of header variables can be used by custom code in the tracker or with
+a tracker's \fBhttp_auth_header\fP configuration option to allows a
+front end server to authenticate a user and pass the user identity to
+roundup.
+.TP
 \fB-s\fP
-Enables to use of SSL.
+Enables use of SSL.
 .TP
 \fB-e\fP \fIfile\fP
 Sets a filename containing the PEM file to use for SSL. If left blank, a
@@ -45,6 +52,10 @@ temporary self-signed certificate will be used.
 \fB-N\fP
 Log client machine names instead of IP addresses (much slower).
 .TP
+\fB-V\fP \fIHTTPVER\fP
+By default roundup-server uses HTTP/1.1 to enable keepalives for faster
+response. HTTPVER can be set to \fBHTTP/1.0\fP to disable keepalives.
+.TP
 \fB-u\fP \fIUID\fP
 Runs the Roundup web server as this UID.
 .TP