Abstract
Each Juniper Networks router running JUNOS Internet software release 4.3B2 or later supports the JUNOScript API. The JUNOScript API is an XML application that Juniper Networks routers use to exchange information with client applications.
Because JUNOScript is an XML application, you can leverage the myriad Perl modules in the public domain to ease the development of client applications that monitor and configure Juniper Networks routers. There are many modules in CPAN (http://www.cpan.org) and other Perl source repositories that provide ways to manipulate XML data (for example, XML::Parser, and XML::DOM modules).
The JUNOS::Device module provides an object-oriented interface for communicating with the JUNOScript server so you can start using the JUNOScript API quickly and easily. There are several modules in this library but client applications directly invoke the Device object only. When the client application creates a JUNOS::Device object, it specifies a router name and the login name to use when accessing the router (which determines the client application's access level).
The following code segment shows how to use the JUNOS::Device object to request information from a Juniper Networks router. This example invokes the query called get_chassis_inventory. For a list of valid queries and the corresponding arguments, invoke the command man JUNOS::Device after completing the installation.
# Step 1: set up the query
my $query = "get_chassis_inventory";
my %queryargs = ( detail => 1 );
# Step 2: Create a JUNOScript Device object
my %deviceinfo = (
access => "telnet",
login => "johndoe",
password => "secret",
hostname => "router11"
);
my $jnx = new JUNOS::Device(%deviceinfo);
unless ( ref $jnx ) {
die "ERROR: Failed to create device\n";
}
# Step 3: connect to the Juniper Networks router
unless ( $jnx->connect() ) {
die "ERROR: Failed to connect\n";
}
# Step 4: send the query and receive a XML::DOM object
my $res = $jnx->$query( %queryargs );
unless ( ref $res ) {
die "ERROR: Failed to execute command\n";
}
# Step 5: check for error
my $err = $res->getFirstError();
if ($err) {
print STDERR "ERROR: $deviceinfo{'hostname'} - ", $err->{message}, "\n";
} else {
# Step 6: do something with the result, just traverse through
# the $res (an XML::DOM object) and do what you need to do.
}
# Step 7: always close the session & connection when you're done
$jnx->request_end_session();
$jnx->disconnect();
Documents
The following documents are available at http://www.juniper.net/beta for the beta release and http://www.juniper.net/support for final release of each version of the JUNOS Internet software.
The following classes provide perldoc to describe their interfaces. Run man <class> after the installation is complete.
Supported Platforms
The current version of this module has been tested on the following platforms. Later releases may support additional platforms.
Downloads
Client Perl applications can communicate with the JUNOScript server either via Telnet, SSH or SSL. SSH and SSL available only in the domestic distribution.
To download the publicly available Telnet-only version of the JUNOScript Perl Client, perform the following steps:
To download the domestic version of the JUNOScript Perl Client (which supports both Telnet, SSH and SSL), perform the following steps:
Installation
Notes for private directory installation:
Running the Sample Scripts
The JUNOScript Perl distribution includes sample scripts that demonstrate how to use JUNOScript to retrieve and change the configuration of a Juniper Networks router. The samples reside in the junoscript-n.n/examples directory.
Reading configuration: Chassis Inventory
This example sends a <get-chassis-information> request to the Juniper Networks router and displays the result to the standard output. Depending on the
command line option, it uses XSLT to display the result in plain text, HTML, or raw XML. The purpose of this example is to show the power and flexibility of combining the
JUNOScript and XSLT.
Example:
[/my/junoscript-n.n/examples/get_chassis_inventory]% perl get_chassis_inventory.pl router11
login: johndoe
password:
Where:
-d
Optional. The default is debug off. If this flag is present, all debugging statements from the JUNOS modules will be sent to standard output.
-x <xslfile>
-o <outputfile>
Optional. If <xslfile> is specified, the <xslfile> is used for rendering the output.
If <xslfile> is
not specified, xsl/chassis_inventory_csv.xsl is used by default. You can
use any of the three XSL files (csv, html, and xml) or create your own. If
<outputfile> is specified, the transformation will be put into <outputfile>. If <outputfile> is not specified,
the result will be displayed on the standard output.
-m <access>
Optional. The default value is telnet. It specifies which transport should be used to communicate with the Juniper Networks router. The valid values are
ssh, ssl, clear-text, and telnet.
-l <login>
-p <password>
The login identity and password to use when accessing the Juniper Networks router. The login identity must already exist in the router configuration and must have at least
read privilege on the router. (Configure the login account by using the CLI command set system login user.) If these arguments are not provided on the command
line, the user will be prompted to enter the information.
<router>
The host name or IP address of the router.
Changing configuration: Load Configuration
This example simply selects one of set_login_user_foo.xml or set_login_class_bar.xmlas the example configuration to load. They are included in the
requests directory. There you will see the XML files containing the RPC requests. You can put your own configuration file in the requests directory and
have load_configuration load it in the target router for you. The purpose of this example is to show you how simple it is to change your router configuration using
JUNOScript. See JUNOScript API Reference for the detail description of the configuration you can submit via JUNOScript.
Example:
[/my/junoscript-n.n/examples/load_configuration]% perl load_configuration.pl
requests/set_login_user_foo.xml router11
login: johndoe
password:
Where:
-d
Optional. The default is debug off. If this flag is present, all debugging statements from the JUNOS modules will be sent to standard output.
-t
Optional. The default value is xml. If specified, the configuration in
the request file is text, not xml.
-a <action>
Optional. The default value is merge. It specifies which load action to
take. The valid values are merge, override, and replace.
-m <access>
Optional. The default value is telnet. It specifies which transport should be used to communicate with the Juniper Networks router. The valid values are
ssh, ssl, clear-text, and telnet.
-l <login>
-p <password>
The login identity and password to use when accessing the Juniper Networks router. The login identity must already exist in the router configuration and must have at least
read privilege on the router. (Configure the login account by using the CLI command set system login user.) If these arguments are not provided on the command
line, the user will be prompted to enter the information.
<request>
Specify the name of the configuration file to be loaded. The configuration files included with the example are set_login_user_foo.xml and
set_login_class_bar.xml, both of which reside in the requests directory.
If -t is specified, the configuration in this file should be in text format.
Example of configuration file content in xml format:
<configuration>
<system>
<host-name>my-host-name</host-name>
</system>
</configuration>
Example of configuration file content in text format:
<configuration-text>
system {
host-name my-host-name;
}
</configuration-text>
<router>
The host name or IP address of the router.
Router Diagnostics: Diagnose BGP
This example retrieves the BGP summary from a Juniper Networks router and displays key information on the unestablished peers. It shows how useful diagnostic tools can be
written using JUNOScript.
You also have an option to render the output in plain text or DHTML (it allows you to dynamically sort any column) using XSL. The output is saved in a file named <router>.xml which is the concatenation of the <get-bgp-summary-information> responses on all of the BGP peers for the target router. Take a look at this XML file if you wish to write your own XSL file to render the output.
Example:
[/my/junoscript-n.n/examples/diagnose_bgp]% perl diagnose_bgp.pl -x xsl/html.xsl
-o router11.html router11
login: johndoe
password:
Where:
-d
Optional. The default is debug off. If this flag is present, all debugging statements from the JUNOS modules will be sent to standard output.
-m <access>
Optional. The default value is telnet. It specifies which transport should be used to communicate with the Juniper Networks router. The valid values are
ssh, ssl, clear-text, and telnet.
-l <login>
-p <password>
The login identity and password to use when accessing the Juniper Networks router. The login identity must already exist in the router configuration and must have at least
read privilege on the router. (Configure the login account by using the CLI command set system login user.) If these arguments are not provided on the command
line, the user will be prompted to enter the information.
-x <xslfile>
-o <outputfile>
Optional. If <xslfile> is specified, the <xslfile> is used for rendering the output. If <xslfile> is
not specified, xsl/text.xsl is used by default. You can use any of the
three XSL files (text, html, and dhtml) or create your own. If
<outputfile> is specified, the transformation will be put into <outputfile>. If <outputfile> is not specified,
the result will be displayed on the standard output.
<router>
The host name or IP address of the router.
XML <-> RDB scrambler/descrambler
Additional Dependencies:
The installation section above does not install modules required by this
example. It is mainly because a Relational Database must be installed
before the required Perl modules can be installed successfully. We keep
this installation separate so you can run the other examples without
having to worry about installing and running the RDB.
This example uses MySQL as its relational database, hence you must first install the MySQL database. The version we have tested this example with is 3.23. Simply go to http://mysql.com/downloads/mysql-3.23.html to download the stable release of the MySQL database. Then follow the installation instructions in Docs/manual.html after you ungzip and untar the MySQL archive.
Check whether all the Perl modules required by this example are installed.
[/my/junoscript-n.n]% perl required-mod.pl RDB
If any of the following Perl modules is not installed, you must install it before running this example. See Installation of Perl Modules Required by Examples.
Description:
These scripts convert a Juniper Networks XML configuration retrieved via the get_config.pl script into a set of relational database tables, populate the tables
with data from the XML file, extract data from those tables, and transform it back into XML format. No other functionality is provided. The SQL output by the
make_tables.pl script is pretty generic SQL and has been tested to work with MySQL on FreeBSD 4.2. It should also work with other RDB products if you install the
DBD module for your RDB.
Before running the example, edit the $DSN value in common.pm to reflect your configuration.
The scripts perform the following functions:
Perform the following steps:
Here's a concrete example:
Installation of PERL
Installation of Perl Modules Required by Examples
You can tell install-prereqs.pl to install only the modules required by JUNOS::Device or by a specific example. By default install-prereqs.pl install all required modules for JUNOS::Device, get_chassis_inventory.pl, load_configuration.pl and diagnose_bgp.pl. The RDB installation is kept separate because it required the installation of a RDB. This section shows you how to specify which set of modules to install.
Notes for private directory installation:
Dependencies
When you run the install script, you'll see the list of C libraries, executables, and Perl modules required by JUNOS::Device and its examples. The only module that the install script does not address is the mysql distribution. To run the RDB example, you must first install mysql before running the installation for RDB.
If you wish to find out what are missing dependencies on your system without running the install script, you can run the following commands.
FAQ
% ls -R diagnose_bgp_dhtml.html js/ ./js: sorttable.jsIf sorttable.js is not the problem, remove the following line from the DHTML file. Some versions of browsers do not like the <meta> info generated by the XSLT processor.
Support
If you have problems with this JUNOS package, please e-mail support@juniper.net. We are looking forward to hearing from you.