Using Ansible with Junos PyEZ Tables to Retrieve Operational Information from Devices Running Junos OS
Module Overview
Junos PyEZ operational (op) Tables provide a simple and efficient way to extract information from complex operational command output. Juniper Networks provides Ansible modules that enable you to leverage Junos PyEZ op Tables from within Ansible playbooks. Table 1 outlines the modules.
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Starting in Juniper.junos Release 2.0.0, the juniper_junos_table module replaces the functionality of the junos_get_table module.
The modules do not work with configuration Tables and Views.
Understanding Junos PyEZ Tables
Junos PyEZ is a microframework for Python that enables you to manage and automate devices running Junos OS. Junos PyEZ supports using simple YAML definitions, which are referred to as Tables and Views, to retrieve and filter operational command output and configuration data from devices running Junos OS.
Junos PyEZ operational (op) Tables extract information from
the output of operational commands or RPCs. The Junos PyEZ jnpr.junos.op modules contain predefined Table and
View definitions for some common RPCs. You can also create custom
Tables and Views.
When you use Ansible to manage devices running Junos OS, the table and juniper_junos_table modules can use Junos PyEZ Tables to retrieve data from a device.
The modules can reference the predefined operational Tables and Views
that are included with the Junos PyEZ distribution, or they can reference
user-defined Tables and Views that reside on the Ansible control node.
For general information about Junos PyEZ Tables and Views, see the following sections and related documentation in the Junos PyEZ Developer Guide:
How to Use the Juniper Networks Ansible Modules with Junos PyEZ Tables
The table and juniper_junos_table modules can include the following arguments to specify the Table
to use:
file—Filename of the YAML file that defines the Junos PyEZ Table and View.path—(Optional) Path to the directory containing the YAML file with the Table and View definitions. The default file path is the location of the predefined Junos PyEZ op Tables, which reside in the Junos PyEZ install path under the jnpr/junos/op directory.table—(Optional) Name of the Table that will be used to retrieve the data. This option is only required when a file contains multiple Table definitions or the file contains a single Table that does not include "Table" in its name.
For example, the following task retrieves data by using
a custom table named FPCTable, which is
defined in the fpc.yaml file located
in the playbook directory:
tasks:
- name: Get FPC info
juniper.device.table:
file: "fpc.yaml"
path: "{{ playbook_dir }}"
table: "FPCTable"
The module’s response includes the resource key, which contains a list of items returned by the Table. Each
list item is a dictionary containing the field names defined by the
View and the value extracted from the data for each of the corresponding
fields.
Consider the following predefined Table and View, ArpTable and ArpView, in
the arp.yml file of the Junos PyEZ
distribution. ArpTable executes the <get-arp-table-information> RPC with the <no-resolve/> option, which is equivalent to the show arp no-resolve CLI command. The corresponding View extracts
the MAC address, IP address, and interface name for each <arp-table-entry> item in the response.
---
ArpTable:
rpc: get-arp-table-information
args:
no-resolve: True
item: arp-table-entry
key: mac-address
view: ArpView
ArpView:
fields:
mac_address: mac-address
ip_address: ip-address
interface_name: interface-nameThe following Ansible playbook executes the table module, which uses ArpTable to retrieve Address Resolution Protocol (ARP) information from devices
running Junos OS. Because ArpTable is included
with the Junos PyEZ distribution and resides in the default directory
for the predefined Junos PyEZ op Tables, the path module argument is not required to specify the file location. In
addition, because ArpTable is the only
Table defined in the file and includes ”Table" in its name,
the table argument is not required to specify
the Table.
---
- name: Get ARP information
hosts: dc1
connection: local
gather_facts: no
tasks:
- name: Get ARP information using Junos PyEZ Table
juniper.device.table:
file: "arp.yml"
register: result
- name: Print response
debug:
var: resultThe playbook output, which is truncated for brevity,
includes the corresponding fields, as defined by the View, for each <arp-table-entry> item returned by the device.
TASK [Print response] *********************************************************
ok: [dc1a.example.net] => {
"result": {
"changed": false,
"failed": false,
"msg": "Successfully retrieved 2 items from ArpTable.",
"resource": [
{
"interface_name": "em0.0",
"ip_address": "10.0.0.5",
"mac_address": "02:01:00:00:00:05"
},
{
"interface_name": "fxp0.0",
"ip_address": "198.51.100.10",
"mac_address": "30:7c:5e:48:4b:40"
},
]
}
}The following Ansible playbook leverages the predefined
Junos PyEZ operational Table, OspfInterfaceTable to retrieve information about OSPF interfaces on devices running
Junos OS. The ospf.yml file defines
multiple Tables and Views, so the module call includes the table argument to specify which Table to use.
---
- name: Get OSPF information
hosts: dc1
connection: local
gather_facts: no
tasks:
- name: Get OSPF interface information
juniper.device.table:
file: "ospf.yml"
table: "OspfInterfaceTable"
register: result
- name: Print response
debug:
var: resultSpecifying RPC Arguments
Junos PyEZ operational Tables have an optional args key that defines the default command options and
arguments for the RPC executed by that Table. The application executes
the RPC with the default options unless the user overrides the defaults.
In Junos PyEZ applications, you can override the default command options
or pass additional options and arguments to the RPC when calling the get() method.
The table and juniper_junos_table modules also enable you to override the default command options
defined in the Table or pass additional options and arguments to the
RPC by using the kwargs argument. The kwargs value is a dictionary of command options and
values, which must be supported by the RPC and the device on which
the RPC is executed.
For example, the predefined Junos PyEZ op Table EthPortTable in the ethport.yml file executes the <get-interface-information> RPC with the media command option and returns information
for all interfaces that match the given regular expression for the
interface name.
EthPortTable:
rpc: get-interface-information
args:
media: True
interface_name: '[afgxe][et]-*'
args_key: interface_name
item: physical-interface
view: EthPortView
The following Ansible playbook uses EthPortTable to extract information about the interfaces on devices running Junos
OS. The kwargs argument includes interface_name: "ge-1/0/0", which overrides the EthPortTable default for interface_name and instructs the module to retrieve the requested fields for only
the ge-1/0/0 interface.
---
- name: Get interface information
hosts: dc1
connection: local
gather_facts: no
tasks:
- name: Get interface information for Ethernet interfaces
juniper.device.table:
file: "ethport.yml"
kwargs:
interface_name: "ge-1/0/0"
register: result
- name: Print response
debug:
var: resultFor more information about the default and user-supplied command options and arguments in Junos PyEZ Tables, see Defining Junos PyEZ Operational Tables and Using Junos PyEZ Operational Tables and Views.