POE::Component::Server::SimpleHTTP(3)

NAME
POE::Component::Server::SimpleHTTP - Perl extension to serve HTTP requests in POE.

VERSION
version 2.30

SYNOPSIS
        use POE;
        use POE::Component::Server::SimpleHTTP;

        # Start the server!
        POE::Component::Server::SimpleHTTP->new(
                'ALIAS'         =>      'HTTPD',
                'PORT'          =>      11111,
                'HOSTNAME'      =>      'MySite.com',
                'HANDLERS'      =>      [
                        {
                                'DIR'           =>      '^/bar/.*',
                                'SESSION'       =>      'HTTP_GET',
                                'EVENT'         =>      'GOT_BAR',
                        },
                        {
                                'DIR'           =>      '^/$',
                                'SESSION'       =>      'HTTP_GET',
                                'EVENT'         =>      'GOT_MAIN',
                        },
                        {
                                'DIR'           =>      '^/foo/.*',
                                'SESSION'       =>      'HTTP_GET',
                                'EVENT'         =>      'GOT_NULL',
                        },
                        {
                                'DIR'           =>      '.*',
                                'SESSION'       =>      'HTTP_GET',
                                'EVENT'         =>      'GOT_ERROR',
                        },
                ],

                'LOGHANDLER' => { 'SESSION' => 'HTTP_GET',
                                  'EVENT'   => 'GOT_LOG',
                },

                'LOG2HANDLER' => { 'SESSION' => 'HTTP_GET',
                                  'EVENT'   => 'POSTLOG',
                },

                # In the testing phase...
                'SSLKEYCERT'    =>      [ 'private-key.pem', 'public-cert.pem' ],
                'SSLINTERMEDIATECACERT' =>      'intermediate-ca-cert.pem',
        ) or die 'Unable to create the HTTP Server';

        # Create our own session to receive events from SimpleHTTP
        POE::Session->create(
                inline_states => {
                        '_start'        =>      sub {   $_[KERNEL]->alias_set( 'HTTP_GET' );
                                                        $_[KERNEL]->post( 'HTTPD', 'GETHANDLERS', $_[SESSION], 'GOT_HANDLERS' );
                                                },

                        'GOT_BAR'       =>      \&GOT_REQ,
                        'GOT_MAIN'      =>      \&GOT_REQ,
                        'GOT_ERROR'     =>      \&GOT_ERR,
                        'GOT_NULL'      =>      \&GOT_NULL,
                        'GOT_HANDLERS'  =>      \&GOT_HANDLERS,
                        'GOT_LOG'       =>      \&GOT_LOG,
                },
        );

        # Start POE!
        POE::Kernel->run();

        sub GOT_HANDLERS {
                # ARG0 = HANDLERS array
                my $handlers = $_[ ARG0 ];

                # Move the first handler to the last one
                push( @$handlers, shift( @$handlers ) );

                # Send it off!
                $_[KERNEL]->post( 'HTTPD', 'SETHANDLERS', $handlers );
        }

        sub GOT_NULL {
                # ARG0 = HTTP::Request object, ARG1 = HTTP::Response object, ARG2 = the DIR that matched
                my( $request, $response, $dirmatch ) = @_[ ARG0 .. ARG2 ];

                # Kill this!
                $_[KERNEL]->post( 'HTTPD', 'CLOSE', $response );
        }

        sub GOT_REQ {
                # ARG0 = HTTP::Request object, ARG1 = HTTP::Response object, ARG2 = the DIR that matched
                my( $request, $response, $dirmatch ) = @_[ ARG0 .. ARG2 ];

                # Do our stuff to HTTP::Response
                $response->code( 200 );
                $response->content( 'Some funky HTML here' );

                # We are done!
                # For speed, you could use $_[KERNEL]->call( ... )
                $_[KERNEL]->post( 'HTTPD', 'DONE', $response );
        }

        sub GOT_ERR {
                # ARG0 = HTTP::Request object, ARG1 = HTTP::Response object, ARG2 = the DIR that matched
                my( $request, $response, $dirmatch ) = @_[ ARG0 .. ARG2 ];

                # Check for errors
                if ( ! defined $request ) {
                        $_[KERNEL]->post( 'HTTPD', 'DONE', $response );
                        return;
                }

                # Do our stuff to HTTP::Response
                $response->code( 404 );
                $response->content( "Hi visitor from " . $response->connection->remote_ip . ", Page not found -> '" . $request->uri->path . "'" );

                # We are done!
                # For speed, you could use $_[KERNEL]->call( ... )
                $_[KERNEL]->post( 'HTTPD', 'DONE', $response );
        }

        sub GOT_LOG {
                # ARG0 = HTTP::Request object, ARG1 = remote IP
                my ($request, $remote_ip) = @_[ARG0,ARG1];

                # Do some sort of logging activity.
                # If the request was malformed, $request = undef
                # CHECK FOR A REQUEST OBJECT BEFORE USING IT.
        if( $request ) {
        {
                warn join(' ', time(), $remote_ip, $request->uri ), "\n";
        } else {
                warn join(' ', time(), $remote_ip, 'Bad request' ), "\n";
        }

                return;
        }

DESCRIPTION
This module makes serving up HTTP requests a breeze in POE.

The hardest thing to understand in this module is the HANDLERS. That's it!

The standard way to use this module is to do this:

        use POE;
        use POE::Component::Server::SimpleHTTP;

        POE::Component::Server::SimpleHTTP->new( ... );

        POE::Session->create( ... );

        POE::Kernel->run();

  Starting SimpleHTTP
To start SimpleHTTP, just call it's new method:

        POE::Component::Server::SimpleHTTP->new(
                'ALIAS'         =>      'HTTPD',
                'ADDRESS'       =>      '192.168.1.1',
                'PORT'          =>      11111,
                'HOSTNAME'      =>      'MySite.com',
                'HEADERS'       =>      {},
                'HANDLERS'      =>      [ ],
        );

This method will die on error or return success.

This constructor accepts only 7 options.

"ALIAS"
    This will set the alias SimpleHTTP uses in the POE Kernel. This will default to "SimpleHTTP"

"ADDRESS"
    This value will be passed to POE::Wheel::SocketFactory to bind to, will use INADDR_ANY if it is nothing is provided (or IN6ADDR_ANY if DOMAIN is AF_INET6). For UNIX domain sockets, it should be a path describing the socket's filename.

    If neither DOMAIN nor ADDRESS are specified, it will use IN6ADDR_ANY and AF_INET6.

"PORT"
    This value will be passed to POE::Wheel::SocketFactory to bind to.

"DOMAIN"
    This value will be passed to POE::Wheel::SocketFactory to define the socket domain used (AF_INET, AF_INET6, AF_UNIX).

"HOSTNAME"
    This value is for the HTTP::Request's URI to point to. If this is not supplied, SimpleHTTP will use Sys::Hostname to find it.

"HEADERS"
    This should be a hashref, that will become the default headers on all HTTP::Response objects. You can override this in individual requests by setting it via $request->header( ... )

    For more information, consult the HTTP::Headers module.

"HANDLERS"
    This is the hardest part of SimpleHTTP :)

    You supply an array, with each element being a hash. All the hashes should contain those 3 keys:

    DIR    ->    The regexp that will be used, more later.

    SESSION    ->    The session to send the input

    EVENT    ->    The event to trigger

    The DIR key should be a valid regexp. This will be matched against the current request path. Pseudocode is: if ( $path =~ /$DIR/ )

    NOTE: The path is UNIX style, not MSWIN style ( /blah/foo not \blah\foo )

    Now, if you supply 100 handlers, how will SimpleHTTP know what to do? Simple! By passing in an array in the first place, you have already told SimpleHTTP the order of your handlers. They will be tried in order, and if a match is not found, SimpleHTTP will return a 404 response.

    This allows some cool things like specifying 3 handlers with DIR of: '^/foo/.*', '^/$', '.*'

    Now, if the request is not in /foo or not root, your 3rd handler will catch it, becoming the "404 not found" handler!

    NOTE: You might get weird Session/Events, make sure your handlers are in order, for example: '^/', '^/foo/.*' The 2nd handler will NEVER get any requests, as the first one will match ( no $ in the regex )

    Now, here's what a handler receives:

    ARG0 -> HTTP::Request object

    ARG1 -> POE::Component::Server::SimpleHTTP::Response object

    ARG2 -> The exact DIR that matched, so you can see what triggered what

    NOTE: If ARG0 is undef, that means POE::Filter::HTTPD encountered an error parsing the client request, simply modify the HTTP::Response object and send some sort of generic error. SimpleHTTP will set the path used in matching the DIR regexes to an empty string, so if there is a "catch-all" DIR regex like '.*', it will catch the errors, and only that one.

    NOTE: The only way SimpleHTTP will leak memory ( hopefully heh ) is if you discard the SimpleHTTP::Response object without sending it back to SimpleHTTP via the DONE/CLOSE events, so never do that!

"KEEPALIVE"
    Set to true to enable HTTP keep-alive support. Connections will be kept alive until the client closes the connection. All HTTP/1.1 connections are kept-open, unless you set the response "Connection" header to "close".

        $response->header( Connection => 'close' );

    If you want more control, use POE::Component::Server::HTTP::KeepAlive.

"LOGHANDLER"
    Expects a hashref with the following key, values:

    SESSION    ->    The session to send the input

    EVENT    ->    The event to trigger

    You will receive an event for each request to the server from clients. Malformed client requests will not be passed into the handler. Instead undef will be passed. Event is called before ANY content handler is called.

    The event will have the following parameters:

    ARG0 -> HTTP::Request object/undef if client request was malformed.

    ARG1 -> the IP address of the client

"LOG2HANDLER"
    Expect a hashref with the following key, values:

    SESSION    ->    The session to send the input

    EVENT    ->    The event to trigger

    You will receive an event for each response that hit DONE call. Malformed client requests will not be passed into the handler. Event is after processing all content handlers.

    The event will have the following parameters:

    ARG0 -> HTTP::Request object

    ARG1 -> HTTP::Response object

    That makes possible following code:

            my ($login, $password) = $request->authorization_basic();
            printf STDERR "%s - %s [%s] \"%s %s %s\" %d %d\n",
                    $response->connection->remote_ip, $login||'-', POSIX::strftime("%d/%b/%Y:%T %z",localtime(time())),
                    $request->method(), $request->uri()->path(), $request->protocol(),
                    $response->code(), length($response->content());

    Emulate apache-like logs for PoCo::Server::SimpleHTTP

"SETUPHANDLER"
    Expects a hashref with the following key, values:

    SESSION    ->    The session to send the input

    EVENT    ->    The event to trigger

    You will receive an event when the listener wheel has been setup.

    Currently there are no parameters returned.

"SSLKEYCERT"
    This should be an arrayref of only 2 elements - the private key and public certificate locations. Now, this is still in the experimental stage, and testing is greatly welcome!

    Again, this will automatically turn every incoming connection into a SSL socket. Once enough testing has been done, this option will be augmented with more SSL stuff!

"SSLINTERMEDIATECACERT"
    This option is needed in case the SSL certificate references an intermediate certification authority certificate.

"PROXYMODE"
    Set this to a true value to enable the server to act as a proxy server, ie. it won't mangle the HTTP::Request URI.

  Events
SimpleHTTP is so simple, there are only 8 events available.

"DONE"
            This event accepts only one argument: the HTTP::Response object we sent to the handler.

            Calling this event implies that this particular request is done, and will proceed to close the socket.

            NOTE: This method automatically sets those 3 headers if they are not already set:
                    Date            ->      Current date stringified via HTTP::Date->time2str
                    Content-Type    ->      text/html
                    Content-Length  ->      length( $response->content )

            To get greater throughput and response time, do not post() to the DONE event, call() it!
            However, this will force your program to block while servicing web requests...

"CLOSE"
            This event accepts only one argument: the HTTP::Response object we sent to the handler.

            Calling this event will close the socket, not sending any output

"GETHANDLERS"
            This event accepts 2 arguments: The session + event to send the response to

            This event will send back the current HANDLERS array ( deep-cloned via Storable::dclone )

            The resulting array can be played around to your tastes, then once you are done...

"SETHANDLERS"
            This event accepts only one argument: pointer to HANDLERS array

            BEWARE: if there is an error in the HANDLERS, SimpleHTTP will die!

"SETCLOSEHANDLER"
        $_[KERNEL]->call( $_[SENDER], 'SETCLOSEHANDLER', $connection,
                          $event, @args );

    Calls $event in the current session when $connection is closed. You could use for persistent connection handling.

    Multiple session may register close handlers.

    Calling SETCLOSEHANDLER without $event to remove the current session's handler:

       $_[KERNEL]->call( $_[SENDER], 'SETCLOSEHANDLER', $connection );

    You must make sure that @args doesn't cause a circular reference. Ideally, use "$connection-"ID> or some other unique value associated with this $connection.

"STARTLISTEN"
            Starts the listening socket, if it was shut down

"STOPLISTEN"
            Simply a wrapper for SHUTDOWN GRACEFUL, but will not shutdown SimpleHTTP if there is no more requests

"SHUTDOWN"
            Without arguments, SimpleHTTP does this:
                    Close the listening socket
                    Kills all pending requests by closing their sockets
                    Removes it's alias

            With an argument of 'GRACEFUL', SimpleHTTP does this:
                    Close the listening socket
                    Waits for all pending requests to come in via DONE/CLOSE, then removes it's alias

"STREAM"
            With a $response argument it streams the content and calls back the streaming event
            of the user's session (or with the dont_flush option you're responsible for calling
            back your session's streaming event).

            To use the streaming feature see below.

  Streaming with SimpleHTTP
It's possible to send data as a stream to clients (unbuffered and integrated in the POE loop).

Just create your session to receive events from SimpleHTTP as usually and add a streaming event, this event will be triggered over and over each time you set the $response to a streaming state and once you trigger it:

   # sets the response as streamed within our session which alias is HTTP_GET
   # with the event GOT_STREAM
   $response->stream(
      session     => 'HTTP_GET',
      event       => 'GOT_STREAM',
      dont_flush  => 1
   );

   # then you can simply yield your streaming event, once the GOT_STREAM event
   # has reached its end it will be triggered again and again, until you
   # send a CLOSE event to the kernel with the appropriate response as parameter
   $kernel->yield('GOT_STREAM', $response);

The optional dont_flush option gives the user the ability to control the callback to the streaming event, which means once your stream event has reached its end it won't be called, you have to call it back.

You can now send data by chunks and either call yourself back (via POE) or shutdown when your streaming is done (EOF for example).

   sub GOT_STREAM {
      my ( $kernel, $heap, $response ) = @_[KERNEL, HEAP, ARG0];

      # sets the content of the response
      $response->content("Hello World\n");

      # send it to the client
      POE::Kernel->post('HTTPD', 'STREAM', $response);

      # if we have previously set the dont_flush option
      # we have to trigger our event back until the end of
      # the stream like this (that can be a yield, of course):
      #
      # $kernel->delay('GOT_STREAM', 1, $stream );

      # otherwise the GOT_STREAM event is triggered continuously until
      # we call the CLOSE event on the response like that :
      #
      if ($heap{'streaming_is_done'}) {
         # close the socket and end the stream
         POE::Kernel->post('HTTPD', 'CLOSE', $response );
      }
   }

The dont_flush option is there to be able to control the frequency of flushes to the client.

  SimpleHTTP Notes
You can enable debugging mode by doing this:

        sub POE::Component::Server::SimpleHTTP::DEBUG () { 1 }
        use POE::Component::Server::SimpleHTTP;

Also, this module will try to keep the Listening socket alive. if it dies, it will open it again for a max of 5 retries.

You can override this behavior by doing this:

        sub POE::Component::Server::SimpleHTTP::MAX_RETRIES () { 10 }
        use POE::Component::Server::SimpleHTTP;

For those who are pondering about basic-authentication, here's a tiny snippet to put in the Event handler

        # Contributed by Rocco Caputo
        sub Got_Request {
                # ARG0 = HTTP::Request, ARG1 = HTTP::Response
                my( $request, $response ) = @_[ ARG0, ARG1 ];

                # Get the login
                my ( $login, $password ) = $request->authorization_basic();

                # Decide what to do
                if ( ! defined $login or ! defined $password ) {
                        # Set the authorization
                        $response->header( 'WWW-Authenticate' => 'Basic realm="MyRealm"' );
                        $response->code( 401 );
                        $response->content( 'FORBIDDEN.' );

                        # Send it off!
                        $_[KERNEL]->post( 'SimpleHTTP', 'DONE', $response );
                } else {
                        # Authenticate the user and move on
                }
        }

  EXPORT
Nothing.

ABSTRACT
        An easy to use HTTP daemon for POE-enabled programs

SEE ALSO
        L<POE>

        L<POE::Filter::HTTPD>

        L<HTTP::Request>

        L<HTTP::Response>

        L<POE::Component::Server::SimpleHTTP::Connection>

        L<POE::Component::Server::SimpleHTTP::Response>

        L<POE::Component::Server::SimpleHTTP::PreFork>

        L<POE::Component::SSLify>

AUTHOR
Apocalypse <APOCAL@cpan.org>

COPYRIGHT AND LICENSE
This software is copyright (c) 2023 by Apocalypse, Chris Williams, Eriam Schaffter, Marlon Bailey and Philip Gwyn.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.