Asterisk::AMI(3p)

NAME
Asterisk::AMI - Perl module for interacting with the Asterisk Manager Interface

VERSION
0.2.8

SYNOPSIS
        use Asterisk::AMI;
        my $astman = Asterisk::AMI->new(PeerAddr => '127.0.0.1',
                                        PeerPort => '5038',
                                        Username => 'admin',
                                        Secret => 'supersecret'
                                );

        die "Unable to connect to asterisk" unless ($astman);

        my $action = $astman->({ Action => 'Command',
                                 Command => 'sip show peers'
                                });

DESCRIPTION
This module provides an interface to the Asterisk Manager Interface. It's goal is to provide a flexible, powerful, and reliable way to interact with Asterisk upon which other applications may be built. It utilizes AnyEvent and therefore can integrate very easily into event-based applications, but it still provides blocking functions for us with standard scripting.

  SSL SUPPORT INFORMATION
For SSL support you will also need the module that AnyEvent::Handle uses for SSL support, which is not a required dependency. Currently that module is 'Net::SSLeay' (AnyEvent:Handle version 5.251) but it may change in the future.

CentOS/Redhat

If the version of Net:SSLeay included in CentOS/Redhat does not work try installing an updated version from CPAN.

  Constructor
new([ARGS])

Creates a new AMI object which takes the arguments as key-value pairs.

        Key-Value Pairs accepted:
        PeerAddr        Remote host address        <hostname>
        PeerPort        Remote host port        <service>
        Events Enable/Disable Events 'on'|'off'
        Username        Username to access the AMI
        Secret Secret used to connect to AMI
        AuthType        Authentication type to use for login        'plaintext'|'MD5'
        UseSSL Enables/Disables SSL for the connection 0|1
        BufferSize        Maximum size of buffer, in number of actions
        Timeout Default timeout of all actions in seconds
        Handlers        Hash reference of Handlers for events        { 'EVENT' => \&somesub };
        Keepalive        Interval (in seconds) to periodically send 'Ping' actions to asterisk
        TCP_Keepalive        Enables/Disables SO_KEEPALIVE option on the socket        0|1
        Blocking        Enable/Disable blocking connects        0|1
        on_connect        A subroutine to run after we connect
        on_connect_err        A subroutine to call if we have an error while connecting
        on_error        A subroutine to call when an error occurs on the socket
        on_disconnect        A subroutine to call when the remote end disconnects
        on_timeout        A subroutine to call if our Keepalive times out
        OriginateHack        Changes settings to allow Async Originates to work 0|1

        'PeerAddr' defaults to 127.0.0.1.
        'PeerPort' defaults to 5038.
        'Events' default is 'off'. May be anything that the AMI will accept as a part of the 'Events' parameter for the
        login action.
        'Username' has no default and must be supplied.
        'Secret' has no default and must be supplied.
        'AuthType' sets the authentication type to use for login. Default is 'plaintext'.  Use 'MD5' for MD5 challenge
        authentication.
        'UseSSL' defaults to 0 (no ssl). When SSL is enabled the default PeerPort changes to 5039.
        'BufferSize' has a default of 30000. It also acts as our max actionid before we reset the counter.
        'Timeout' has a default of 0, which means no timeout on blocking.
        'Handlers' accepts a hash reference setting a callback handler for the specified event. EVENT should match
        the contents of the {'Event'} key of the event object will be. The handler should be a subroutine reference that
        will be passed the a copy of the AMI object and the event object. The 'default' keyword can be used to set
        a default event handler. If handlers are installed we do not buffer events and instead immediately dispatch them.
        If no handler is specified for an event type and a 'default' was not set the event is discarded.
        'Keepalive' only works when running with an event loop. Used with on_timeout, this can be used to detect if
        asterisk has become un-responsive.
        'TCP_Keepalive' default is disabled. Activates the tcp keep-alive at the socket layer. This does not require
        an event-loop and is lightweight. Useful for applications that use long-lived connections to Asterisk but
        do not run an event loop.
        'Blocking' has a default of 1 (block on connecting). A value of 0 will cause us to queue our connection
        and login for when an event loop is started. If set to non blocking we will always return a valid object.

        'on_connect' is a subroutine to call when we have successfully connected and logged into the asterisk manager.
        it will be passed our AMI object.

        'on_connect_err', 'on_error', 'on_disconnect'
        These three specify subroutines to call when errors occur. 'on_connect_err' is specifically for errors that
        occur while connecting, as well as failed logins. If 'on_connect_err' or 'on_disconnect' it is not set,
        but 'on_error' is, 'on_error' will be called. 'on_disconnect' is not reliable, as disconnects seem to get lumped
        under 'on_error' instead. When the subroutine specified for any of theses is called the first argument is a copy
        of our AMI object, and the second is a string containing a message/reason. All three of these are 'fatal', when
        they occur we destroy our buffers and our socket connections.

        'on_timeout' is called when a keep-alive has timed out, not when a normal action has. It is non-'fatal'.
        The subroutine will be called with a copy of our AMI object and a message.

        'OriginateHack' defaults to 0 (off). This essentially enables 'call' events and says 'discard all events
        unless the user has explicitly enabled events' (prevents a memory leak). It does its best not to mess up
        anything you have already set. Without this, if you use 'Async' with an 'Originate' the action will timeout
        or never callback. You don't need this if you are already doing work with events, simply add 'call' events
        to your eventmask.

  Disabling Warnings
        If you have warnings enabled this module will emit a number of them on connection errors, deprecated features, etc.
        To disable this but still have all other warnings in perl enabled you can do the following:

                use Asterisk::AMI;
                use warnings;
                no warnings qw(Asterisk::AMI);

        That will enable warnings but disable any warnings from this module.

  Warning - Mixing Event-loops and blocking actions
        For an intro to Event-Based programming please check out the documentation in AnyEvent::Intro.

        If you are running an event loop and use blocking methods (e.g. get_response, check_response, action,
        simple_action, connected, or a blocking connect) the outcome is unspecified. It may work, it may lock everything up, the action may
        work but break something else. I have tested it and behavior seems unpredictable at best and is very
        circumstantial.

        If you are running an event-loop use non-blocking callbacks! It is why they are there!

        However if you do play with blocking methods inside of your loops let me know how it goes.

  Actions
ActionIDs

This module handles ActionIDs internally and if you supply one in an action it will simply be ignored and overwritten.

Construction

No matter which method you use to send an action (send_action(), simple_action(), or action()), they all accept actions in the same format, which is a hash reference. The only exceptions to this rules are when specifying a callback and a callback timeout, which only work with send_action.

To build and send an action you can do the following:

        %action = ( Action => 'Command',
                    Command => 'sip show peers'
                );

        $astman->send_action(\%action);

Alternatively you can also do the following to the same effect:

        $astman->send_action({  Action => 'Command',
                                Command => 'sip show peers'
                                });

Additionally the value of the hash may be an array reference. When an array reference is used, every value in the array is append as a different line to the action. For example:

        { Variable => [ 'var1=1', 'var2=2' ] }

        Will become:

        Variable: var1=1
        Variable: var2=2

        When the action is sent.

Sending and Retrieving

More detailed information on these individual methods is available below

The send_action() method can be used to send an action to the AMI. It will return a positive integer, which is the ActionID of the action, on success and will return undef in the event it is unable to send the action.

After sending an action you can then get its response in one of two methods.

The method check_response() accepts an actionid and will return 1 if the action was considered successful, 0 if it failed and undef if an error occurred or on timeout.

The method get_response() accepts an actionid and will return a Response object (really just a fancy hash) with the contents of the Action Response as well as any associated Events it generated. It will return undef if an error occurred or on timeout.

All responses and events are buffered, therefor you can issue several send_action()s and then retrieve/check their responses out of order without losing any information. In-fact, if you are issuing many actions in series you can get much better performance sending them all first and then retrieving them later, rather than waiting for responses immediately after issuing an action.

Alternatively you can also use simple_action() and action(). simple_action() combines send_action() and check_response(), and therefore returns 1 on success and 0 on failure, and undef on error or timeout. action() combines send_action() and get_response(), and therefore returns a Response object or undef.

Examples

        Send and retrieve and action:
        my $actionid = $astman->send_action({   Action => 'Command',
                                                Command => 'sip show peers'
                                });

        my $response = $astman->get_response($actionid)

        This is equivalent to the above:
        my $response = $astman->action({        Action => 'Command',
                                                Command => 'sip show peers'
                                });

        The following:
        my $actionid1 = $astman->send_action({  Action => 'Command',
                                                Command => 'sip show peers'
                                });

        my $actionid2 = $astman->send_action({  Action => 'Command',
                                                Command => 'sip show peers'
                                });

        my $actionid3 = $astman->send_action({  Action => 'Command',
                                                Command => 'sip show peers'
                                });

        my $response3 = $astman->get_response($actionid3);
        my $response1 = $astman->get_response($actionid1);
        my $response2 = $astman->get_response($actionid2);

        Can be much faster than:
        my $response1 = $astman->action({       Action => 'Command',
                                                Command => 'sip show peers'
                                });
        my $response2 = $astman->action({       Action => 'Command',
                                                Command => 'sip show peers'
                                });
        my $response3 = $astman->action({       Action => 'Command',
                                                Command => 'sip show peers'
                                });

Originate Examples

        These don't include non-blocking examples, please read the section on 'Callbacks' below for information
        on using non-blocking callbacks and events.

        NOTE: Please read about the 'OriginateHack' option for the constructor above if you plan on using the 'Async'
        option in your Originate command, as it may be required to properly retrieve the response.

        In these examples we are dialing extension '12345' at a sip peer named 'peer' and when the call connects
        we drop the channel into 'some_context' at priority 1 for extension 100.

        Example 1 - A simple non-ASYNC Originate

        my $response = $astman->action({Action => 'Originate',
                                        Channel => 'SIP/peer/12345',
                                        Context => 'some_context',
                                        Exten => 100,
                                        Priority => 1});

        And the contents of respone will look similiar to the following:

        {
                'Message' => 'Originate successfully queued',
                'ActionID' => '3',
                'GOOD' => 1,
                'COMPLETED' => 1,
                'Response' => 'Success'
        };

        Example 2 - Originate with multiple variables
        This will set the channel variables 'var1' and 'var2' to 1 and 2, respectfully.
        The value for the 'Variable' key should be an array reference or an anonymous array in order
        to set multiple variables.

        my $response = $astman->action({Action => 'Originate',
                                        Channel => 'SIP/peer/12345',
                                        Context => 'some_context',
                                        Exten => 100,
                                        Priority => 1,
                                        Variable = [ 'var1=1', 'var2=2' ]});

        Example 3 - An Async Originate
        If your Async Originate never returns please read about the 'OriginateHack' option for the constructor.

        my $response = $astman->action({Action => 'Originate',
                                        Channel => 'SIP/peer/12345',
                                        Context => 'some_context',
                                        Exten => 100,
                                        Priority => 1,
                                        Async => 1});

        And the contents of response will look similiar to the following:

        {
                'Message' => 'Originate successfully queued',
                'EVENTS' => [
                        {
                                'Exten' => '100',
                                'CallerID' => '<unknown>',
                                'Event' => 'OriginateResponse',
                                'Privilege' => 'call,all',
                                'Channel' => 'SIP/peer-009c5510',
                                'Context' => 'some_context',
                                'Response' => 'Success',
                                'Reason' => '4',
                                'CallerIDName' => '<unknown>',
                                'Uniqueid' => '1276543236.82',
                                'ActionID' => '3',
                                'CallerIDNum' => '<unknown>'
                        }
                        ],
                'ActionID' => '3',
                'GOOD' => 1,
                'COMPLETED' => 1,
                'Response' => 'Success'
        };

        More Info:
        Check out the voip-info.org page for more information on the Originate action.
        http://www.voip-info.org/wiki/view/Asterisk+Manager+API+Action+Originate

Callbacks

        You may also specify a subroutine to callback when using send_action as well as a timeout.

        An example of this would be:
        $astman->send_action({ Action => 'Ping' }, \&somemethod, 7, $somevar);

In this example once the action 'Ping' finishes we will call somemethod() and pass it the a copy of our AMI object, the Response Object for the action, and an optional variable $somevar. If a timeout is not specified it will use the default set. A value of 0 means no timeout. When the timeout is reached somemethod() will be called and passed a reference to our $astman and the uncompleted Response Object, therefore somemethod() should check the state of the object. Checking the key {'GOOD'} is usually a good indication if the response is useable.

        Anonymous subroutines are also acceptable as demostrated in the examples below:
        my $callback = sub { return };

        $astman->send_action({ Action => 'Ping' }, $callback, 7);

        Or

        $astman->send_action({ Action => 'Ping' }, sub { return }, 7);

Callback Caveats

Callbacks only work if we are processing packets, therefore you must be running an event loop. Alternatively, we run mini-event loops for our blocking calls (e.g. action(), get_action()), so in theory if you set callbacks and then issue a blocking call those callbacks should also get triggered. However this is an unsupported scenario.

Timeouts are done using timers and they are set as soon as you send the object. Therefore if you send an action with a timeout and then monkey around for a long time before getting back to your event loop (to process input) you can time out before ever even attempting to receive the response.

        A very contrived example:
        $astman->send_action({ Action => 'Ping' }, \&somemethod, 3);

        sleep(4);

        #Start loop
        $astman->loop;
        #Oh no we never even tried to get the response yet it will still time out

  Passing Variables in an Action Response
Sometimes, when working in an event framework, you want a way to associate/map the response to an action with another identifier used in your application. Normally you would have to maintain some sort of separate mapping involving the ActionID to accomplish this. This modules provides a generic way to pass any perl scalar (this includes references) with your action which is then passed to the callback with the response.

Passing

The variable to be passed to the callback should be passed as the fourth argument to the send_action() method.

For example to pass a simple scalar value:

        my $vartostore = "Stored";

        $astman->send_action({ Action => 'Ping' }, \&somemethod, undef, $vartostore });

And to pass a reference:

        my @vartostore = ("One", "Two");

        $astman->send_action({ Action => 'Ping' }, \&somemethod, undef,  \@vartostore });

Retrieving

The passed variable will be available as the third argument to the callback.

To retrieve in a callback:

        my ($astman, $resp, $store) = @_;

        print $store . " was stored\n";

  Responses and Events
        NOTE: Empty fields sent by Asterisk (e.g. 'Account: ' with no value in an event) are represented by the hash
        value of null string, not undef. This means you need to test for ''
        (e.g. if ($response->{'Account'} ne '')) ) for any values that might be possibly be empty.

Responses

        Responses are returned as response objects, which are hash references, structured as follows:

        $response->{'Response'} Response to our packet (Success, Failed, Error, Pong, etc).
                   {'ActionID'} ActionID of this Response.
                   {'Message'} Message line of the response.
                   {'EVENTS'} Array reference containing Event Objects associated with this actionid.
                   {'PARSED'} Hash reference of lines we could parse into key->value pairs.
                   {'CMD'} Contains command output from 'Action: Command's. It is an array reference.
                   {'COMPLETED'} 1 if completed, 0 if not (timeout)
                   {'GOOD'} 1 if good, 0 if bad. Good means no errors and COMPLETED.

Events

        Events are turned into event objects, these are similar to response objects, but their keys vary much more
        depending on the specific event.

        Some common contents are:

        $event->{'Event'} The type of Event
                {'ActionID'} Only available if this event was caused by an action

Event Handlers

        Here is a very simple example of how to use event handlers. Please note that the key for the event handler
        is matched against the event type that asterisk sends. For example if asterisk sends 'Event: Hangup' you use a
        key of 'Hangup' to match it. This works for any event type that asterisk sends.

        my $astman = Asterisk::AMI->new(PeerAddr        =>        '127.0.0.1',
                                        PeerPort        =>        '5038',
                                        Username        =>        'admin',
                                        Secret => 'supersecret',
                                        Events => 'on',
                                        Handlers        => { default => \&do_event,
                                                             Hangup => \&do_hangup };
                                );

        die "Unable to connect to asterisk" unless ($astman);

        sub do_event {
                my ($asterisk, $event) = @_;

                print 'Yeah! Event Type: ' . $event->{'Event'} . "\r\n";
        }

        sub do_hangup {
                my ($asterisk, $event) = @_;
                print 'Channel ' . $event->{'Channel'} . ' Hungup because ' . $event->{'Cause-txt'} . "\r\n";
        }

        #Start some event loop
        someloop;

  How to use in an event-based application
        Getting this module to work with your event based application is really easy so long as you are running an
        event-loop that is supported by AnyEvent. Below is a simple example of how to use this module with your
        preferred event loop. We will use EV as our event loop in this example. I use subroutine references in this
        example, but you could use anonymous subroutines if you want to.

        #Use your preferred loop before our module so that AnyEvent will auto-detect it
        use EV;
        use Asterisk::AMI:

        #Create your connection
        my $astman = Asterisk::AMI->new(PeerAddr => '127.0.0.1',
                                        PeerPort => '5038',
                                        Username => 'admin',
                                        Secret => 'supersecret',
                                        Events => 'on',
                                        Handlers => { default => \&eventhandler }
                                );
        #Alternatively you can set Blocking => 0, and set an on_error sub to catch connection errors
        die "Unable to connect to asterisk" unless ($astman);

        #Define the subroutines for events
        sub eventhandler { my ($ami, $event) = @_; print 'Got Event: ',$event->{'Event'},"\r\n"; }

        #Define a subroutine for your action callback
        sub actioncb { my ($ami, $response) = @_; print 'Got Action Reponse: ',$response->{'Response'},"\r\n"; }

        #Send an action
        my $action = $astman->({ Action => 'Ping' }, \&actioncb);

        #Do all of you other eventy stuff here, or before all this stuff, whichever ..............

        #Start our loop
        EV::loop

        That's it, the EV loop will allow us to process input from asterisk. Once the action completes it will
        call the callback, and any events will be dispatched to eventhandler(). As you can see it is fairly
        straight-forward. Most of the work will be in creating subroutines to be called for various events and
        actions that you plan to use.

  Methods
send_action ( ACTION, [ [ CALLBACK ], [ TIMEOUT ], [ USERDATA ] ] )

        Sends the action to asterisk, where ACTION is a hash reference. If no errors occurred while sending it returns
        the ActionID for the action, which is a positive integer above 0. If it encounters an error it will return undef.
        CALLBACK is optional and should be a subroutine reference or any anonymous subroutine. TIMEOUT is optional and
        only has an affect if a CALLBACK is specified. USERDATA is optional and is a perl variable that will be passed to
        the CALLBACK in addition to the response.

        The use of the CALLBACK and TIMEOUT keys in the ACTION has been deprecated.

check_response( [ ACTIONID ], [ TIMEOUT ] )

        Returns 1 if the action was considered successful, 0 if it failed, or undef on timeout or error. If no ACTIONID
        is specified the ACTIONID of the last action sent will be used. If no TIMEOUT is given it blocks, reading in
        packets until the action completes. This will remove a response from the buffer.

get_response ( [ ACTIONID ], [ TIMEOUT ] )

        Returns the response object for the action. Returns undef on error or timeout.
        If no ACTIONID is specified the ACTIONID of the last action sent will be used. If no TIMEOUT is given it
        blocks, reading in packets until the action completes. This will remove the response from the buffer.

action ( ACTION [, TIMEOUT ] )

        Sends the action and returns the response object for the action. Returns undef on error or timeout.
        If no ACTIONID is specified the ACTIONID of the last action sent will be used.
        If no TIMEOUT is given it blocks, reading in packets until the action completes. This will remove the
        response from the buffer.

simple_action ( ACTION [, TIMEOUT ] )

        Sends the action and returns 1 if the action was considered successful, 0 if it failed, or undef on error
        and timeout. If no ACTIONID is specified the ACTIONID of the last action sent will be used. If no TIMEOUT is
        given it blocks, reading in packets until the action completes. This will remove the response from the buffer.

disconnect ()

        Logoff and disconnects from the AMI. Returns 1 on success and 0 if any errors were encountered.

get_event ( [ TIMEOUT ] )

        This returns the first event object in the buffer, or if no events are in the buffer it reads in packets
        waiting for an event. It will return undef if an error occurs.
        If no TIMEOUT is given it blocks, reading in packets until an event arrives.

amiver ()

        Returns the version of the Asterisk Manager Interface we are connected to. Undef until the connection is made
        (important if you have Blocking => 0).

connected ( [ TIMEOUT ] )

        This checks the connection to the AMI to ensure it is still functional. It checks at the socket layer and
        also sends a 'PING' to the AMI to ensure it is still responding. If no TIMEOUT is given this will block
        waiting for a response.

        Returns 1 if the connection is good, 0 if it is not.

error ()

        Returns 1 if there are currently errors on the socket, 0 if everything is ok.

destroy ()

        Destroys the contents of all buffers and removes any current callbacks that are set.
        Mostly used internally. Useful if you want to ensure that our IO handle watcher gets removed.
        Gets called automatically when our object goes out of scope.

loop ()

        Starts an event loop via AnyEvent.

break ()

        Breaks/exits the current event loop. The program will continue from where the event loop was invoked.

See Also
AnyEvent, Asterisk::AMI::Common, Asterisk::AMI::Common::Dev

AUTHOR
Ryan Bullock (rrb3942@gmail.com)

BUG REPORTING AND FEEDBACK
Please report any bugs or errors to our github issue tracker at http://github.com/rrb3942/perl-Asterisk-AMI/issues or the cpan request tracker at https://rt.cpan.org/Public/Bug/Report.html?Queue=perl-Asterisk-AMI

LICENSE
Copyright (C) 2011 by Ryan Bullock (rrb3942@gmail.com)

This module is free software. You can redistribute it and/or modify it under the terms of the Artistic License 2.0.

This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.