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Net-Appliance-Session-3.111600
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/ Net::Appliance::Session

NAME

Net::Appliance::Session - Run command-line sessions to network appliances

VERSION

version 3.111600

IMPORTANT NOTE ABOUT UPGRADING FROM VERSION 2.x

Between version 2.x and 3.x of this module the programmer's interface changed in a number of ways. If you have existing code to migrate to this new version, please see the Upgrading document which details all steps necessary.

SYNOPSIS

use Net::Appliance::Session;

my $s = Net::Appliance::Session->new({
    personality => 'ios',
    transport => 'SSH',
    host => 'hostname.example',
    privileged_paging => 1, # only if using ASA/PIX OS 7+
                            # and there are other behaviour options, see below
});

eval {
    $s->connect({ username => 'username', password => 'loginpass' });

    $s->begin_privileged({ password => 'privilegedpass' });
    print $s->cmd('show access-list');
    $s->end_privileged;
};
if ($@) {
    warn "failed to execute command: $@";
}

$s->close;

DESCRIPTION

Use this module to establish an interactive command-line session with a network appliance. There is special support for moving into "privileged" mode and "configure" mode, along with the ability to send commands to the connected device and retrieve returned output.

There are other CPAN modules that cover similar ground, but they are less robust and do not handle native SSH, Telnet and Serial Line connections with a single interface on both Unix and Windows platforms.

Built-in commands come from a phrasebook which supports many network device vendors (Cisco, HP, etc) or you can install a new phrasebook. Most phases of the connection are configurable for different device behaviours.

METHODS

As in the synopsis above, the first step is to create a new instance. Recommended practice is to wrap all other method calls in a Perl eval block to catch errors (typically time-outs waiting for CLI response). For a demonstration of usage, see the example script shipped with this distribution.

Net::Appliance::Session->new( \%options )

my $s = Net::Appliance::Session->new({
    personality => 'ios',
    transport => 'SSH',
    host => 'hostname.example',
});

Prepares a new session for you, but will not connect to any device. Some options are required, others optional:

personality => $name (required)

Tells the module which "language" to use when talking to the connected device, for example ios for Cisco IOS devices. There's a list of all the supported platforms in the Phrasebook documentation. It's also possible to write new phrasebooks.

transport => $backend (required)

The name of the transport backend used for the session, which may be one of Telnet, SSH, or Serial.

app => $location (required on Windows)

On Windows platforms, you must download the plink.exe program, and pass its location in this parameter.

host => $hostname (required for Telnet and SSH transports)

When using the Telnet and SSH transports, you must provide the IP or host name of the target device in this parameter.

connect_options => \%options

Some of the transport backends can take their own options. For example with a serial line connection you might specify the port speed, etc. See the respective manual pages for each transport backend for further details.

connect( \%options )

$s->connect({ username => $myname, password => $mysecret });

To establish a connection to the device, and possibly also log in, call this method. Following a successful connection, paging of device output will be disabled using commands appropriate to the platform. This feature can be suppressed (see "CONFIGURATION", below).

Options available to this method, sometimes required, are:

username => $name

The login username for the device. Whether this is required depends both on how the device is configured, and how you have configured this module to act. If it looks like the device presented a Username prompt. and you don't pass the username a Perl exception will be thrown.

The username is cached within the module for possible use later on when entering "privileged" mode.

password => $secret

The login password for the device. Whether this is required depends both on how the device is configured, and how you have configured this module to act. If it looks like the device presented a Username prompt. and you don't pass the username a Perl exception will be thrown.

The password is cached within the module for possible use later on when entering "privileged" mode.

begin_privileged and end_privileged

$s->begin_privileged;
# do some work
$s->end_privileged;

Once you have connected to the device, change to "privileged" mode by calling the begin_privileged method. The appropriate command will be issued for your device platform, from the phrasebook. Likewise to exit "privileged" mode call the end_privileged method.

Sometimes authentication is required to enter "privileged" mode. In that case, the module defaults to using the username and password first passed in the connect method. However to either override those or set them in case they were not passed to connect, use either or both of the following options to begin_privileged:

$s->begin_privileged({ username => $myname, password => $mysecret });

begin_configure and end_configure

$s->begin_configure;
# make some changes
$s->end_configure;

To enter "configuration" mode for your device platform, call the begin_configure method. This checks you are already in "privileged" mode, as the module assumes this is necessary. If it isn't necessary then see "CONFIGURATION" below to modify this behaviour. Likewise to exit "configure" mode, call the end_configure method.

cmd( $command )

my $config     = $s->cmd('show running-config');
my @interfaces = $s->cmd('show interfaces brief');

Execute a single command statement on the connected device. The statement is executed verbatim on the device, with a newline appended.

In scalar context the response is returned as a single string. In list context the gathered response is returned, only split into a list so that each line is one item.

To handle more complicated interactions, for example commands which prompt for confirmation or optional parameters, you should use a Macro. These are set up in the phrasebook and issued via the $s->macro($name) method call. See the Phrasebook and Cookbook manual pages for further details.

close

$s->close;

Once you have finished work with the device, call this method. It attempts to back out of any "privileged" or "configuration" mode you've entered, re-enable paging (unless suppressed) and then disconnect.

CONFIGURATION

Each of the entries below may either be passed as a parameter in the options to the new method, or called as a method in its own right and passed the appropriate setting. If doing the latter, it should be before you call the connect method.

do_login

Defaults to true. Pass a zero (false) to disable logging in to the device with a username and password, should you get a command prompt immediately upon connection.

do_privileged_mode

Defaults to true. If on connecting to the device your user is immediately in "privieleged" mode, then set this to zero (false), which permits immediate access to "configure" mode.

do_configure_mode

Defaults to true. If you set this to zero (false), the module assumes you're in "configure" mode immediately upon entering "privileged" mode. I can't think why this would be useful but you never know.

do_paging

Defaults to true. Pass a zero (false) to disable the post-login reconfiguration of a device which avoids paged command output. If you cleanly close the device connection then paging is re-enabled. Use this option to suppress these steps.

privileged_paging

Defaults to false. On some series of devices, in particular the Cisco ASA and PIXOS7+ you must be in privileged mode in order to alter the pager. If that is the case for your device, call this method with a true value to instruct the module to better manage the situation.

pager_enable_lines

Defaults to 24. The command issued to re-enable paging (on disconnect) typically takes a parameter which is the number of lines per page. If you want a different value, set it in this option.

pager_disable_lines

Defaults to zero. The command issued to disable paging typically takes a parameter which is the number of lines per page (zero begin to disable paging). If your device uses a different number here, set it in this option.

wake_up

When first connecting to the device, the he most common scenario is that a Username (or some other) prompt is shown. However if no output is forthcoming and nothing matches, the "enter" key is pressed, in the hope of triggering a new prompt. Set this configuration option to zero (false) to suppress this behaviour.

DIAGNOSTICS

To see a log of all the processes within this module, and a copy of all data sent to and received from the device, call the following method:

$s->set_global_log_at('debug');

In place of debug you can have other log levels, and via the embedded Logger at $s->nci->logger it's possible to finely control the diagnostics.

INTERNALS

See Net::CLI::Interact.

AUTHOR

Oliver Gorwits <oliver@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2011 by Oliver Gorwits.

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