NAME

Perinci::Access::HTTP::Server - PSGI application to implement Riap::HTTP

VERSION

This document describes version 0.50 of Perinci::Access::HTTP::Server (from Perl distribution Perinci-Access-HTTP-Server), released on 2014-07-22.

SYNOPSIS

DESCRIPTION

Perinci::Access::HTTP::Server (PeriAHS for short) is a PSGI application (a set of middlewares in Plack::Middleware::PeriAHS::*, really) to implement Riap::HTTP server. You compose the middlewares, configuring each one and including only the ones you need, in your app.psgi, to create an API service.

A simple command-line utility, peri-htserve, is included. This utility runs a provided PSGI application with the Gepok or Starman PSGI server so you can quickly export some Perl modules/functions as an API service with one line of command.

To get started, currently see the source code of peri-htserve to see the basic structure of the PSGI application. Also see each middleware's documentation.

FAQ

I don't want to have to add metadata to every function!

The point of Riap::HTTP is to expose metadata over HTTP, so it's best that you write your metadata for every API function you want to expose.

However, there are tools like Perinci::Gen::ForModule (which the example script peri-htserve uses) which can generate some (generic) metadata for your existing modules.

How can I customize URL?

For example, instead of:

http://localhost:5000/My/API/Adder/func

you want:

http://localhost:5000/adder/func

or perhaps (if you only have one module to expose):

http://localhost:5000/func

You can do this by customizing match_uri when enabling the PeriAHS::ParseRequest middleware (see peri-htserve source code). You just need to make sure that you set $env->{"riap.request"}{uri}.

I want to let user specify output format from URI (e.g. /api/j/... or /api/yaml/...).

Again, this can be achieved by customizing the PeriAHS::ParseRequest middleware. You can do something like:

enable "PeriAHS::ParseRequest"
    match_uri => [
        qr!^/api/(?<f>json|yaml|j|y)/
                 (?<uri>[^?/]+(?:/[^?/]+)?)!x,
        sub {
            my ($env, $m) = @_;
            $env->{"riap.request"}{fmt} = $m->{f} =~ /j/ ? 'json' : 'yaml';
        }
    ];

Another example, allowing format by sticking .json or .yaml at the end of Riap URI:

enable "PeriAHS::ParseRequest"
    match_uri => qr!^(?<uri>[^?/]+(?:/[^?/]+)?)(?:\.(?<fmt>json|yaml))!x;

I need even more custom URI syntax.

You can leave match_uri empty and perform your custom URI parsing in another middleware after PeriAHS::ParseRequest. For example:

enable "PeriAHS::ParseRequest";

# do more URI parsing
enable sub {
    my $app = shift;
    sub {
        my $env     = shift;
        my $rreq    = $env->{"riap.request"};
        # parse more stuff and put it in $rreq
        my $res = $app->($env);
        return $res;
    };
};

I want to support HTTPS.

If you use peri-htserve, supply --https_ports, --ssl_key_file and --ssl_cert_file options.

If you use plackup, use Gepok (-s) as the PSGI server.

If you use PSGI server other than Gepok, you will probably need to run Nginx, Perlbal, or some other external HTTPS proxy.

I don't want to run a standalone daemon.

Use other deployment mechanisms for your PSGI application, of which there are plenty. For example, to deploy as CGI script, see Plack::Handler::CGI. To deploy as FastCGI script (allowing to run under Nginx, for example), see Plack::Handler::FCGI.

I don't want to expose my subroutines and module structure directly!

Well, isn't exposing functions the whole point of API?

If you have modules that you do not want to expose as API, simply disallow it (e.g. using allowed_uris configuration in PeriAHS::ParseRequest middleware. Or, create a set of wrapper modules to expose only the functionalities that you want to expose.

But I want REST-style!

Take a look at Serabi.

I want to support another output format (e.g. XML, MessagePack, etc).

See Perinci::Result::Format.

I want to automatically reload modules that changed on disk.

Use one of the module-reloading module on CPAN, e.g.: Module::Reload or Module::Reload::Conditional.

I want to authenticate clients.

Enable Plack::Middleware::Auth::Basic (or other authen middleware you prefer) before PeriAHS::ParseRequest.

I want to add access control and/or authorize clients.

Take a look at Plack::Middleware::PeriAHS::ACL (currently unfinished) which allows access control based on various conditions. Normally this is put after authentication and before response creation.

I want to support new actions.

Normally you'll need to extend the appropriate Riap clients (e.g. Perinci::Access::Schemeless for this. Again, note that you don't have to resort to subclassing just to accomplish this. You can inject the action_ACTION() method from somewhere else.

I want to serve static files.

Use the usual Plack::Builder's mount() and Plack::Middleware::Static for this.

mount my $app = builder {
    mount "/api" => builder {
        enable "PeriAHS::ParseRequest", ...;
        ...
    },
    mount "/static" => builder {
        enable "Static", path=>..., root=>...;
    },
};

TIPS AND TRICKS

Proxying API server

Not only can you serve local modules, you can also serve remote modules ("http://" or "https://" URIs) making your API server a proxy for another.

Performance tuning

To be written.

SEE ALSO

Perinci::Access

Riap::HTTP

Serabi

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Perinci-Access-HTTP-Server.

SOURCE

Source repository is at https://github.com/sharyanto/perl-Perinci-Access-HTTP-Server.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Perinci-Access-HTTP-Server

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.

AUTHOR

Steven Haryanto <stevenharyanto@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Steven Haryanto.

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