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IO::Iron - Client Libraries to Iron services IronCache, IronMQ and IronWorker.


version 0.14


    use IO::Iron;
    use IO::Iron qw{ironcache ironmq ironworker};
    use IO::Iron ':all';

    my $iron_mq_client = ironmq();
    my @iron_mq_queues = $iron_mq_client->get_queues();

    my $iron_cache_client = ironcache( config => 'iron_cache.json' );
    my @iron_caches = $iron_cache_client->get_caches();

    my $iron_worker_client = ironworker( config => 'iron_worker.json' );
    my @iron_codes = $iron_worker_client->list_code_packages();


IronCache, IronMQ and IronWorker are cloud based services accessible via a REST API. CPAN Distribution IO::Iron contains Perl clients for accessing them.


Please see the individual clients for further documentation and usage.



IO-Iron code is available at Github: IO-Iron for download with Git:


Package IO::Iron is only a "convenience" module for quick startup. The three functions provided are "ironcache", "ironmq" and "ironworker".

The following parameters can be given to each of them as hash item type parameters. See section "SYNOPSIS" for an example.

project_id, The ID of the project to use for requests.
token, The OAuth token that is used to authenticate requests.
host, The domain name the API can be located at. E.g. ''.
protocol, The protocol that will be used to communicate with the API. Defaults to "https".
port, The port to connect to the API through. Defaults to 443.
api_version, The version of the API to connect through. Defaults to the version supported by the client.
timeout, REST client timeout (for REST calls accessing IronMQ.)
config, Config filename with path if required.

You can also give the parameters in the config file .iron.json or iron.json (in local directory) or as environmental variables. Please read Configuring the Official Client Libraries for further details.

Client Documentation

Please read individual client's documentation for using them.


A REST call to Iron service may fail for several reason. All failures generate an exception using the Exception::Class package. Class IronHTTPCallException contains the field status_code, response_message and error. Error is formatted as such: IronHTTPCallException: status_code=<HTTP status code> response_message=<response_message>.

    use Try::Tiny;
    use Scalar::Util qw{blessed};
    try {
        my $asked_iron_cache_01 = $iron_cache_client->get_cache('name' => 'unique_cache_name_01');
    catch {
        die $_ unless blessed $_ && $_->can('rethrow');
        if ( $_->isa('IronHTTPCallException') ) {
            if ($_->status_code == 404) {
                print "Bad things! Can not just find the catch in this!\n";
        else {
            $_->rethrow; # Push the error upwards.

When using policies (see next chapter) also exceptions NoIronPolicyException and CharacterGroupNotDefinedIronPolicyException can be met.


Policies is a way to limit the names of message queues, code packages, caches and items (item keys) to a predefined group of possible strings. This can limit the chances for typos and enforce an enterprise policy. The policies are loaded from a JSON file which is specified either when creating a IO::Iron::Iron*::Client object, or in the config file .iron.json (or equivalent).

Policies in Config file

Add the item policies to the config file. The value of the item is the filename of the policies file.

Example config file:


Policies file specified when creating the client

    my $policies_filename = '/etc/ironmq/global_policies.json';
    my $client = IO::Iron::IronCache::Client->new('policies' => $policies_filename);

Examples of Policies File and Explanation of Configuration

The 'default' policies JSON file:

        "no_limitation":1, # There is an unlimited number of alternatives.
    "queue":{ "name":[ "[:alnum:]{1,}" ], },
        "name":[ "[:alnum:]{1,}" ],
        "item_key":[ "[:alnum:]{1,}" ]
    "worker":{ "name":[ "[:alnum:]{1,}" ], }

The above file would set an open policy for IronMQ, IronCache and IronWorker alike. The file is divided into four parts: definition for defining meta options, and queue|cache|worker parts for defining the changing strings (queue|cache|worker names and item keys). The character group alnum covers all ascii alphabetic characters (both lower and upper case) and digits (0-9).

N.B. The option definition:no_limitation controls the open/closed policy. If definition:no_limitation is set (1=set), the policy control is turned off.

An example of policies file

        "__comment1":"Use normal regexp. [:digit:] = number:0-9, [:alpha:] = alphabetic character, [:alnum:] = character or number.",
        "__comment2":"Do not use end/begin limitators '^' and '\$'. They are added automatically.",
        "__comment3":"Note that character groups are closed inside '[::]', not '[[:]]' as normal POSIX groups.",

This policies file sets policies for cache names and item keys. Both have two templates. Template "cache_01_main" is without wildcards: the template list can also only contain predefined names or keys. Sometimes this could be exactly the wanted behaviour, especially in regard to cache and message queue names.

Items beginning with '__' are considered comments. Comments can not be inserted into lists, such as character_group.

The definition part contains the list character_group for user-defined groups. The following groups are predefined:

[:alpha:], ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
[:alnum:], ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789
[:digit:], 0123456789
[:lower:], abcdefghijklmnopqrstuvwxyz
[:word:], ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_

All lower ASCII (7-bit) characters are allowed in names and in character groups, except for the reserved characters (RFC 3986) !$&'()*+,;=:/?#[]@.

A character group definition is closed inside characters '[::]', not '[[:]]' as normal POSIX groups. Only the equivalents of the POSIX groups mentioned above can be used; e.g. POSIX group [[:graph:]] is not available.

When using the character groups in a name or key, only two markings are allowed: [:group:]{n} and [:group:]{n,n}, where n is an integer. This limitation (not being able to use any regular expression) is due to the double functionality of the policy: a) it acts as a filter when creating and naming new message queues, code packages, caches and cache items; 2) it can be used to list all possible names, for example when querying for cache items.

STATUS libraries are currently being developed so changes in the API are possible.


IO::Iron requires an IronIO account. Three configuration items must be set (others available) before using the functions: project_id, token and host. These can be set in a json file, as environmental variables or as parameters when creating the object.

project_id, the identification string, from IronIO.
token, an OAuth authentication token string, from IronIO.
host, the cloud in which you want to operate, e.g. 'cache-aws-us-east-1' for AWS (Amazon) or '' or '' for Rackspace.

Please see IronMQ HTTP API Reference (hosts) for available hosts.


Subdirectory integ_t contains "integration" tests which require an active account and Internet connection. To run the tests, create first three config files in the main directory: iron_cache.json, iron_mq.json, iron_worker.json. Set at least the following attributes: project_id, token and host.

Execute prove (prove), e.g. prove -lv -Iinteg_t integ_t\Iron\iron_all.t.



Create an IronCache client object and return it to user.


Create an IronMQ client object and return it to user.


Create an IronWorker client object and return it to user.


Mikko Koivunalho <>


Please report any bugs or feature requests to or through the web interface at:


This software is copyright (c) 2023 by Mikko Koivunalho.

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

The full text of the license can be found in the LICENSE file included with this distribution.