NAME

Asterisk::AMI - Perl moduling for interacting with the Asterisk Manager Interface

VERSION

0.1.10

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 INFORMAION

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 sends '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.\n
'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 port 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 or blocking.
'Handlers' accepts a hash reference setting a callback handler for the specified event. EVENT should match the what
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.
'TCP_Keepalive' default is disabled. Actives 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. 

Warning - Mixing Event-loops and blocking actions

If you are running an event loop and use blocking methods (anything that accepts it's timeout outside of 
the action hash e.g. get_response, check_response, action, connected) 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

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 = $actan->get_response($actionid3);
my $response1 = $actan->get_response($actionid1);
my $response2 = $actan->get_response($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'
			});

Callbacks

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

An example of this would be:
send_action({	Action => 'Ping',
		CALLBACK => \&somemethod,
		TIMEOUT => 7 });

In this example once the action 'Ping' finishes we will call somemethod() and pass it the a copy of our AMI object and the Response Object for the action. If 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 the 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 object is useable.

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, depending on how your event loop works it may be relative or absolute. Either way 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:
send_action({	Action => 'Ping',
		CALLBACK => \&somemethod,
		TIMEOUT => 3 });

sleep(4);

#Start some loop
someloop;
#Oh no we never even tried to get the response yet it will still time out

ActionIDs

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

Responses and Events

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.
	   {'DATA'}		Array reference of lines that we could not parse.
	   {'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.

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',
				 CALLBACK => \&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 )

Sends the action to asterisk. 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.

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 ( [ FATAL ] )

Destroys the contents of all buffers and removes any current callbacks that are set. If FATAL is true
it will also destroy our IO handle and its associated watcher. Mostly used internally. Useful if you want to
ensure that our IO handle watcher gets removed. 

loop ()

Starts an eventloop via AnyEvent.

See Also

Asterisk::AMI::Common, Asterisk::AMI::Common::Dev

AUTHOR

Ryan Bullock (rrb3942@gmail.com)

BUG REPORTING AND FEEBACK

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

COPYRIGHT

Copyright (C) 2010 by Ryan Bullock (rrb3942@gmail.com)

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