Gepok - PSGI server with built-in HTTPS support, Unix sockets, preforking


This document describes version 0.292 of Gepok (from Perl distribution Gepok), released on 2019-09-11.


To run with plackup:

 % plackup -s Gepok \
     --http_ports :8081,:8082, \
     --unix_sockets /var/run/gepok.sock,/tmp/gepok.sock \

To run standalone:

 use Gepok;
 my $d = Gepok->new(
     http_ports     => [8081, ':8082', ''], # default none
     https_ports    => [8084, ''],            # default none
     unix_sockets   => ['/var/run/gepok.sock','/tmp/gepok.sock'], # default none
     #ssl_key_file  => '/path/to/key.pem', # required if https_ports specified
     #ssl_cert_file => '/path/to/crt.pem', # required if https_ports specified
     #max_requests_per_child => 100,       # default is 1000
     #start_servers          => 0,         # default is 3, 0 means don't prefork
     #daemonize => 0,       # default is 1, 0 = don't go into background


Gepok is a PSGI server implementation. Its features are:

  • HTTPS support out-of-the-box

    This is the primary (if not the only) reason why I wrote Gepok, and why it uses HTTP::Daemon::* family (because there is HTTP::Daemon::SSL). I needed a pure-Perl standalone webserver with SSL support builtin. Other Perl servers usually recommend running behind Nginx or some other external HTTPS proxy.

  • Preforking

    Good performance and reliability.

  • Multiple interface and Unix socket

  • Runs on Unix platform

Gepok can run under plackup, or standalone.


Gepok adds the following server-specific keys in the PSGI environment passed to application/middleware:

  • gepok.connect_time => ARRAY

    A 2-element arrayref (produced by Time::HiRes' gettimeofday()), clocked at connect time.

  • gepok.finish_request_time => ARRAY

    A 2-element arrayref (produced by Time::HiRes' gettimeofday()), clocked right after Gepok has received the complete request from client.

  • gepok.client_protocol => STR

    HTTP protocol version sent by client, e.g. "HTTP/1.0" or "HTTP/1.1". This can be used to avoid sending HTTP/1.1 response to HTTP/1.0 or older clients.

  • gepok.socket => OBJ

    Raw HTTP::Daemon::ClientConn socket. Can be used to get information about socket, e.g. peerport(), etc. Should not be used to read/write data (use PSGI way for that, e.g. $env->{'psgi.input'}, returning PSGI response, etc).

  • gepok.httpd_socket => OBJ

    Raw HTTP::Daemon socket. Can be used to get information about socket, e.g. peercred() (for UNIX sockets), etc. Should not be used to return HTTP response directly (use PSGI way for that).

  • gepok.unix_socket => BOOL

    A boolean value which is set to true if client connects via Unix socket. (Note, you can get Unix socket path from $env->{SERVER_NAME} or $env->{'gepok.socket'}).


Some code portion taken from Starman.


name => STR (default is basename of $0)

Name of server, for display in process table ('ps ax').

daemonize => BOOL (default 1)

Whether to daemonize (go into background).

http_ports => ARRAY OF STR (default [])

One or more HTTP ports to listen to. Default is none. Each port can be in the form of N, ":N", "" (all means the same thing, to bind to all interfaces) or "" (to bind to a specific network interface).

A string is also accepted, it will be split (delimiter ,) beforehand.

https_ports => ARRAY OF STR (default [])

Just like http_ports, but for specifying ports for HTTPS.

unix_sockets => ARRAY OF STR (default [])

Location of Unix sockets. Default is none, which means not listening to Unix socket. Each element should be an absolute path.

A string is also accepted, it will be split (delimiter ,) beforehand.

You must at least specify one port (either http, https, unix_socket) or Gepok will refuse to run.

timeout => BOOL (default 120)

Socket timeout. Will be passed as Timeout option to HTTP::Daemon's constructor (which will be passed to IO::Socket).

require_root => BOOL (default 0)

Whether to require running as root.

Passed to Proc::Daemon::Prefork's constructor.

pid_path => STR (default /var/run/<name>.pid or ~/<name>.pid)

Location of PID file.

scoreboard_path => STR (default /var/run/<name>.scoreboard or ~/<name>.scoreboard)

Location of scoreboard file (used for communication between parent and child processes). If you disable this, autoadjusting number of children won't work (number of children will be kept at 'start_servers').

error_log_path => STR (default /var/log/<name>-error.log or ~/<name>-error.log)

Location of error log. Default is /var/log/<name>-error.log. It will be opened in append mode.

access_log_path => STR (default /var/log/<name>-access.log or ~/<name>-access.log)

Location of access log. It will be opened in append mode.

Default format of access log is the Apache combined format. Override access_log() method if you wan't to customize this.

If Gepok is run Under plackup, by default it will not write an access log file (unless you specify this attribute) since plackup already writes an access log.

ssl_key_file => STR

Path to SSL key file, to be passed to HTTP::Daemon::SSL. If you specify one or more HTTPS ports, you need to supply this.

ssl_cert_file => STR

Path to SSL cert file, to be passed to HTTP::Daemon::SSL. If you specify one or more HTTPS ports, you need to supply this.

ssl_verify_mode => INT

Level of verification for SSL client certificates, to be passed to HTTP::Daemon::SSL. This is optional.

ssl_verify_callback => CODEREF

Custom verifier for SSL client certificates, to be passed to HTTP::Daemon::SSL. This is optional.

ssl_ca_file => STR

Path for file containing certificates of reputable authorties for certificate verification. This is optional.

ssl_ca_path => STR

According to IO::Socket::SSL this is only of interest if you are "unusually friendly with the OpenSSL documentation". This is optional.

start_servers => INT (default 3)

Number of children to fork at the start of run. If you set this to 0, the server becomes a nonforking one.

Tip: You can set start_servers to 0 and 'daemonize' to false for debugging.

max_clients => INT (default 150)

Maximum number of children processes to maintain. If server is busy, number of children will be increased from the original 'start_servers' up until this value.

max_requests_per_child => INT (default 1000)

Number of requests each child will serve until it exists.

product_name => STR

Used in 'Server' HTTP response header (<product_name>/<version>). Defaults to class name, e.g. "Gepok".

product_version => STR

Used in 'Server' HTTP response header (<product_name>/<version>). Defaults to $VERSION package variable.



Create a new instance of server. %args can be used to set attributes.


Start/run server and run the PSGI application $app.


Alias for run().


Stop running server.


Restart server.

$gepok->is_running() => BOOL

Check whether server is running.


This is a hook provided for subclasses to do something before the daemon is preforking. For example, you can preload Perl modules here so that each child doesn't have to load modules separately (= inefficient).

$gepok->access_log($req, $res, $sock)

The default implementation uses the Apache combined format. Override if you want custom format. $res is HTTP::Request object, $res is PSGI response, $sock is the raw socket.


Why the name Gepok?

Gepok is an Indonesian word, meaning bundle/bunch. This class bundles one or several HTTP::Daemon::* objects to create a stand-alone web server.

Why use Gepok?

The main feature for Gepok is builtin HTTPS support, which means you do not have to setup a separate front-end HTTPS proxy for serving content over HTTPS. This is convenient, especially for development. Builtin HTTPS support also makes some things easier to, e.g. check client certificates you can use the ssl_verify_callback options. Your PSGI application also has direct access to the raw socket ($env->{'gepok.socket'}).

However, for heavy traffic use, you might want to check out more battle-tested solution like Perlbal.

There are now other PSGI servers that support HTTPS, see the SEE ALSO section.

I personally developed Gepok for two reasons: HTTPS support and listening on Unix sockets.

Performance notes?

Thanks to preforking, Gepok has adequate performance and reliability handling multiple clients. But Gepok is not yet performance-tuned, or very performance-oriented to begin with. For convenience Gepok is based on HTTP::Daemon, which is also not too performance-oriented. For each HTTP request, HTTP::Daemon constructs an HTTP::Request object, which copies request body into a scalar (and, for PSGI, needs to be re-presented as a stream using IO::Scalar). Creating other objects like URI and HTTP::Headers are also involved. Gepok also creates file-based scoreboard, which might or might not be a bottleneck.

Casual benchmarking on my PC shows that Gepok is about 3-4x slower than Starman for "hello world" PSGI.

I am using Gepok primarily with Perinci::Access::HTTP::Server for serving remote API requests, in which HTTPS support is required.

"Bad arg length for Socket::inet_ntoa, length is 16, should be 4" error

At the time of this writing, HTTP::Daemon (6.01) might throw this error message when receiving request. For patches/solutions to overcome this problem, see:


Please visit the project's homepage at


Source repository is at


Please report any bugs or feature requests on the bugtracker website

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.


PSGI and Plack.

HTTP server classes used: HTTP::Daemon, HTTP::Daemon::SSL, HTTP::Daemon::UNIX.


Other PSGI servers that support Unix sockets: Starman.

Other PSGI servers that support HTTPS out of the box:

  • Plack::Handler::AnyEvent::HTTPD

    As of Aug 2012 still needs a patch to allow SSL, see

Note that any PSGI server can be used if you setup a front-end HTTPS proxy/load balancer.

Please drop me a message if you think other PSGI servers need to be mentioned.


perlancar <>


This software is copyright (c) 2019, 2014, 2013, 2012, 2011 by

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