POE::Component::NetSNMP::agent - AgentX clients with NetSNMP::agent and POE
Version 0.400
Like a traditional NetSNMP::agent,
made POE aware:
use NetSNMP::agent;
use POE qw< Component::NetSNMP::agent >;
my $agent = POE::Component::NetSNMP::agent->spawn(
Alias => "snmp_agent",
AgentX => 1,
);
$agent->register(".1.3.6.1.4.1.32272", \&agent_handler);
POE::Kernel->run;
exit;
sub agent_handler {
my ($kernel, $heap, $args) = @_[ KERNEL, HEAP, ARG1 ];
my ($handler, $reg_info, $request_info, $requests) = @$args;
# the rest of the code works like a classic NetSNMP::agent callback
my $mode = $request_info->getMode;
for (my $request = $requests; $request; $request = $request->next) {
if ($mode == MODE_GET) {
# ...
}
elsif ($mode == MODE_GETNEXT) {
# ...
}
else {
# ...
}
}
}
Simpler, let the module do the boring stuff, but keep control of the loop:
use NetSNMP::ASN;
use POE qw< Component::NetSNMP::agent >;
POE::Session->create(
inline_states => {
_start => sub {
$_[HEAP]{agent} = POE::Component::NetSNMP::agent->spawn(
Alias => "snmp_agent",
AgentX => 1,
AutoHandle => ".1.3.6.1.4.1.32272",
);
$_[KERNEL]->yield("update_tree");
},
update_tree => \&update_tree,
},
);
POE::Kernel->run;
exit;
sub update_tree {
my ($kernel, $heap) = @_[ KERNEL, HEAP ];
# populate the OID tree at regular intervals with
# the add_oid_entry and add_oid_tree events
}
Even simpler, let the module do all the boring stuff, leaving you nothing more to do than providing the handlers to update the OID trees:
use NetSNMP::ASN;
use POE::Component::NetSNMP::agent;
my $agent = POE::Component::NetSNMP::agent->new(
AgentX => 1,
AutoHandle => ".1.3.6.1.4.1.32272",
AutoUpdate => [[ \&update_tree, 30 ]],
);
$agent->run;
sub update_tree {
my ($self) = @_;
# populate the OID tree with the add_oid_entry() and add_oid_tree()
# methods, a la SNMP::Extension::PassPersist
}
See also in eg/ for more ready-to-use examples.
This module is a thin wrapper around NetSNMP::agent to use it within a POE-based program, its basic use being the same as you would do without POE: register one or more OIDs with their associated callbacks, then within a callback process & answer the requests with setValue(), setOID(), setError(), etc.
POE::Component::NetSNMP::agent also provides a simpler mechanism, similar to SNMP::Extension::PassPersist, if you just want to handle get and getnext requests over an OID tree: set the Autohandle option to the a OID, then add OID entries with add_oid_entry or add_oid_tree.
The module will try to automatically recover from a lost connection with AgentX master (see the Ping option), but you can force a check by posting to agent_check;
Note that most of the API is available both as POE events and as object methods, in an attempt to make it a bit easier for people not fully used to POE.
This module can use Sort::Key::OID when it is available, for sorting OIDs faster than with the internal pure Perl function.
Create and return a POE session for handling NetSNMP requests.
NetSNMP::agent options
Name - (optional) sets the agent name, defaulting to "perl". The underlying library will try to read a $name.conf Net-SNMP configuration file.AgentX - (optional) be a sub-agent (0 = false, 1 = true). The Net-SNMP master agent must be running first.Ports - (optional) sets the ports this agent will listen on (e.g.: "udp:161,tcp:161").Component options
Alias - (optional) sets the session aliasAutoHandle - (optional) sets the component to auto-handle get and getnext request to the given OIDDebug - (optional) when true, enables debug mode on this sessionPing - (optional) sets the ping delay between manual agent checks in seconds; default is 10 secondsErrback - (optional) sets the error callback.Example:
my $agent = POE::Component::NetSNMP::agent->spawn(
Alias => "snmp_agent",
AgentX => 1,
);
Simpler constructor: create all the POE sessions and events to handle absolutely all the boring stuff; just provide handlers to update the OID trees. Accept the same arguments than span plus the following:
AutoUpdate - expects a definition of handlers and their respective delay (in seconds) in the form of an array of arrays:
AutoUpdate => [
[ CODEREF, DELAY ],
...
],
Examples:
# create an agent with a single handler, called every 30 sec
my $agent = POE::Component::NetSNMP::agent->new(
AgentX => 1,
AutoHandle => ".1.3.6.1.4.1.32272",
AutoUpdate => [[ \&update_tree, 30 ]],
);
# create an agent with two handlers, called respectively
# every 10 and every 20 seconds
my $agent = POE::Component::NetSNMP::agent->new(
AgentX => 1,
AutoHandle => ".1.3.6.1.4.1.32272",
AutoUpdate => [
[ \&update_tree_1, 10 ],
[ \&update_tree_2, 20 ],
],
);
Run the main loop (executes POE::Kernel->run)
Register a callback handler for a given OID.
Arguments:
Example:
$agent->register(".1.3.6.1.4.1.32272.1", \&tree_1_handler);
$agent->register(".1.3.6.1.4.1.32272.2", \&tree_2_handler);
Add an OID entry to be auto-handled by the agent.
Arguments:
NetSNMP::ASN like ASN_COUNTER, ASN_GAUGE, ASN_OCTET_STR..Example:
$agent->add_oid_entry(".1.3.6.1.4.1.32272.1", ASN_OCTET_STR, "oh hai");
$agent->add_oid_entry(".1.3.6.1.4.1.32272.2", ASN_OCTET_STR,
"i can haz oh-eye-deez??");
Add multiple OID entries to be auto-handled by the agent.
Arguments:
{
OID => [ ASN_TYPE, VALUE ],
...
}
Example:
%oid_tree = (
".1.3.6.1.4.1.32272.1" => [ ASN_OCTET_STR, "oh hai" ];
".1.3.6.1.4.1.32272.2" => [ ASN_OCTET_STR, "i can haz oh-eye-deez??" ];
);
$agent->add_oid_tree(\%oid_tree);
Register a callback handler for a given OID.
Arguments:
Example:
POE::Kernel->post($agent, register => ".1.3.6.1.4.1.32272.1", "tree_1_handler");
POE::Kernel->post($agent, register => ".1.3.6.1.4.1.32272.2", "tree_2_handler");
Add an OID entry to be auto-handled by the agent.
Arguments:
NetSNMP::ASN like ASN_COUNTER, ASN_GAUGE, ASN_OCTET_STR..Example:
POE::Kernel->post($agent, add_oid_entry =>
".1.3.6.1.4.1.32272.1", ASN_OCTET_STR, "oh hai");
POE::Kernel->post($agent, add_oid_entry =>
".1.3.6.1.4.1.32272.2", ASN_OCTET_STR, "i can haz oh-eye-deez??");
Add multiple OID entries to be auto-handled by the agent.
Arguments:
{
OID => [ ASN_TYPE, VALUE ],
...
}
Example:
%oid_tree = (
".1.3.6.1.4.1.32272.1" => [ ASN_OCTET_STR, "oh hai" ];
".1.3.6.1.4.1.32272.2" => [ ASN_OCTET_STR, "i can haz oh-eye-deez??" ];
);
POE::Kernel->post($agent, add_oid_tree => \%oid_tree);
NetSNMP::agent, NetSNMP::ASN, NetSNMP::OID
Net-SNMP web site: http://www.net-snmp.org/
You can find documentation for this module with the perldoc command.
perldoc POE::Component::NetSNMP::agent
You can also look for information at:
https://rt.cpan.org/Public/Dist/Display.html?Name=POE-Component-NetSNMP-agent
Please report any bugs or feature requests to bug-poe-component-netsnmp-agent at rt.cpan.org, or through the web interface at https://rt.cpan.org/Public/Dist/Display.html?Name=POE-Component-NetSNMP-agent. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
Thanks to Rocco Caputo and Rob Bloodgood for their help on #poe.
Sébastien Aperghis-Tramoni <sebastien at aperghis.net>
Copyright 2011 Sébastien Aperghis-Tramoni.
This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.
