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Web::API(3pm) User Contributed Perl Documentation Web::API(3pm)

NAME

Web::API - A Simple base module to implement almost every RESTful API with just a few lines of configuration

VERSION

version 2.4.1

SYNOPSIS

NOTE: as of version 2.1 "strict_ssl" is enabled by default for obvious security reasons, this may break your current library implementation, sorry.

Implement the RESTful API of your choice in 10 minutes, roughly.

    package Net::CloudProvider;

    use Mouse;
    
    with 'Web::API';

    our $VERSION = "0.1";

    has 'commands' => (
        is      => 'rw',
        default => sub {
            {
                list_nodes => { method => 'GET' },
                node_info  => { method => 'GET', require_id => 1 },
                create_node => {
                    method             => 'POST',
                    default_attributes => {
                        allowed_hot_migrate            => 1,
                        required_virtual_machine_build => 1,
                        cpu_shares                     => 5,
                        required_ip_address_assignment => 1,
                        primary_network_id             => 1,
                        required_automatic_backup      => 0,
                        swap_disk_size                 => 1,
                    },
                    mandatory => [
                        'label',
                        'hostname',
                        'template_id',
                        'cpus',
                        'memory',
                        'primary_disk_size',
                        'required_virtual_machine_build',
                        'cpu_shares',
                        'primary_network_id',
                        'required_ip_address_assignment',
                        'required_automatic_backup',
                        'swap_disk_size',
                    ]
                },
                update_node => { method => 'PUT',    require_id => 1 },
                delete_node => { method => 'DELETE', require_id => 1 },
                start_node  => {
                    method       => 'POST',
                    require_id   => 1,
                    post_id_path => 'startup',
                },
                stop_node => {
                    method       => 'POST',
                    require_id   => 1,
                    post_id_path => 'shutdown',
                },
                suspend_node => {
                    method       => 'POST',
                    require_id   => 1,
                    post_id_path => 'suspend',
                },
            };
        },
    );

    sub commands {
        my ($self) = @_;
        return $self->commands;
    }

    sub BUILD {
        my ($self) = @_;

        $self->user_agent(__PACKAGE__ . ' ' . $VERSION);
        $self->base_url('https://ams01.cloudprovider.net/virtual_machines');
        $self->content_type('application/json');
        $self->extension('json');
        $self->wrapper('virtual_machine');
        $self->mapping({
                os        => 'template_id',
                debian    => 1,
                id        => 'label',
                disk_size => 'primary_disk_size',
        });

        return $self;
    }

    1;

later use as:

    use Net::CloudProvider;
    
    my $nc = Net::CloudProvider->new(user => 'foobar', api_key => 'secret');
    my $response = $nc->create_node({
        id                             => 'funnybox',
        hostname                       => 'node.funnybox.com',
        os                             => 'debian',
        cpus                           => 2,
        memory                         => 256,
        disk_size                      => 5,
        allowed_hot_migrate            => 1,
        required_virtual_machine_build => 1,
        cpu_shares                     => 5,
        required_ip_address_assignment => 1,
    });

ATTRIBUTES

commands

most important configuration part of the module which has to be provided by the module you are writing.

the following keys are valid/possible:

    method
    path
    mandatory
    default_attributes
    headers
    extension
    content_type
    incoming_content_type
    outgoing_content_type
    wrapper
    query_keys
    require_id (deprecated, use path)
    pre_id_path (deprecated, use path)
    post_id_path (deprecated, use path)

the request path for commands is being build as:

    $base_url/$path.$extension

an example for "path":

    path => 'users/:user_id/labels'

this will add "user_id" to the list of mandatory keys for this command automatically.

base_url (required)

get/set base URL to API, can include paths

api_key (required in most cases)

get/set API key (also used as basic auth password)

user (optional)

get/set API username/account name

api_key_field (optional)

get/set name of the hash key that has to hold the "api_key" e.g. in POST content payloads

api_version (optional)

get/set API version to be used

default: 1

mapping (optional)

supply mapping table, hashref of format { "key" => "value", ... }

wrapper (optional)

get/set name of the key that is used to wrap all options of a command in. unfortunately some APIs increase the depth of a hash by wrapping everything into a single key (who knows why...), which means this: 

    $wa->command(%options);

turns %options into:

    { wrapper => \%options }

before encoding and sending it off.

header (optional)

get/set custom headers sent with every request

auth_type

get/set authentication type. currently supported are only 'basic', 'header', 'hash_key', 'get_params', 'oauth_header', 'oauth_params' or 'none'

default: none

auth_header (optional)

get/set the name of the header used for Authorization credentials

default: Authorization

default_method (optional)

get/set default HTTP method

default: GET

extension (optional)

get/set file extension, e.g. '.json'

user_agent (optional)

get/set User Agent String

default: "Web::API $VERSION"

timeout (optional)

get/set LWP::UserAgent timeout

strict_ssl (optional)

enable/disable strict SSL certificate hostname checking as a convenience alternatively you can supply your own LWP::Useragent compatible agent for the "agent" attribute.

default: true

agent (optional)

get/set LWP::UserAgent object

retry_http_codes (optional)

get/set array of HTTP response codes that trigger a retry of the request

retry_errors (optional)

define an array reference of regexes that should trigger a retry of the request if matched against an error found via one of the "error_keys"

retry_times (optional)

get/set number of times a request will be retried at most

default: 3

retry_delay (optional)

get/set delay to wait between retries. accepts float for millisecond support.

default: 1.0

content_type (optional)

global content type, which is used for in and out going request/response headers and to encode and decode the payload if no other more specific content types are set, e.g. "incoming_content_type", "outgoing_content_type" or content types set individually per command attribute.

default: 'text/plain'

incoming_content_type (optional)

default: undef

outgoing_content_type (optional)

default: undef

debug (optional)

enable/disabled debug logging

default: false

cookies (optional)

this is used to store and retrieve cookies before and after requests were made to keep authenticated sessions alive for the time this object exists in memory you can add your own cookies to be send with every request. See HTTP::Cookies for more information.

default: HTTP::Cookies->new()

consumer_secret (required for all oauth_* auth_types)

default: undef

access_token (required for all oauth_* auth_types)

default: undef

access_secret (required for all oauth_* auth_types)

default: undef

signature_method (required for all oauth_* auth_types)

default: undef

encoder (custom options encoding subroutine)

Receives "\%options" and "content-type" as the only 2 arguments and has to return a single scalar.

default: undef

decoder (custom response content decoding subroutine)

Receives "content" and "content-type" as the only 2 scalar arguments and has to return a single hash reference.

default: undef

oauth_post_body (required for all oauth_* auth_types)

enable/disable adding of command options as extra parameters to the OAuth request generation and therefor be included in the OAuth signature calculation.

default: true

error_keys

get/set list of array keys that will be search for in the decoded response data structure. the same format as for mandatory keys is supported: 

    some.deeply.nested.error.message

will search for an error message at

    $decoded_response->{some}->{deeply}->{nested}->{error}->{messsage}

and if the key exists and its value is defined it will be provided as "$response-"{error}> and matched against all regexes from the `retry_errors` array ref if provided to trigger a retry on particular errors.

INTERNAL SUBROUTINES/METHODS

nonce

generates new OAuth nonce for every request

log

decode

encode

talk

map_options

check_mandatory

key_exists

wrap

request

retry request with delay if "retry_http_codes" is set, otherwise just try once.

needs_retry

returns true if the HTTP code or error found match either "retry_http_codes" or "retry_errors" respectively. returns false otherwise.

if "retry_errors" are defined it will try to decode the response content and store the decoded structure internally so we don't have to decode again at the end.

needs the last response object and the 'Accept' content type header from the request for decoding.

find_error

go through "error_keys" and find a potential error message in the decoded/parsed response and return it.

format_response

build_uri

build_content_type

configure in/out content types

order of precedence: 1. per command "incoming_content_type" / "outgoing_content_type" 2. per command general "content_type" 3. content type based on file path extension (only for incoming) 4. global "incoming_content_type" / "outgoing_content_type" 5. global general "content_type"

DESTROY

catch DESTROY call and tear down / clean up if necessary at this point there is nothing to do though. This prevents AUTOLOAD from logging an unknown command error message

AUTOLOAD magic

install a method for each new command and call it in an "eval {}" to catch exceptions and set an error in a unified way.

BUGS

Please report any bugs or feature requests on GitHub's issue tracker <https://github.com/nupfel/Web-API/issues>. Pull requests welcome.

SUPPORT

You can find documentation for this module with the perldoc(1) command. 

    perldoc Web::API

You can also look for information at:

SEE ALSO

HTTP::Cookies, LWP::UserAgent, Net::OAuth

AUTHOR

Tobias Kirschstein <lev@cpan.org>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2013 by Tobias Kirschstein.

This is free software, licensed under:

  The (three-clause) BSD License
2019-01-17 perl v5.28.1