The :ref:`cli_parse <ansible_collections.ansible.netcommon.cli_parse_module>` module parses semi-structured data such as network configurations into structured data to allow programmatic use of the data from that device. You can pull information from a network device and update a CMDB in one playbook. Use cases include automated troubleshooting, creating dynamic documentation, updating IPAM (IP address management) tools and so on.
..contents::
:local:
Understanding the CLI parser
=============================
The `ansible.netcommon <https://galaxy.ansible.com/ansible/netcommon>`_ collection version 1.2.0 or later includes the :ref:`cli_parse <ansible_collections.ansible.netcommon.cli_parse_module>` module that can run CLI commands and parse the semi-structured text output. You can use the ``cli_parse`` module on a device, host, or platform that only supports a command-line interface and the commands issued return semi-structured text. The ``cli_parse`` module can either run a CLI command on a device and return a parsed result or can simply parse any text document. The ``cli_parse`` module includes cli_parser plugins to interface with a variety of parsing engines.
Why parse the text?
--------------------
Parsing semi-structured data such as network configurations into structured data allows programmatic use of the data from that device. Use cases include automated troubleshooting, creating dynamic documentation, updating IPAM (IP address management) tools and so on. You may prefer to do this with Ansible natively to take advantage of native Ansible constructs such as:
- The ``when`` clause to conditionally run other tasks or roles
- The ``assert`` module to check configuration and operational state compliance
- The ``template`` module to generate reports about configuration and operational state information
- Templates and ``command`` or ``config`` modules to generate host, device, or platform commands or configuration
- The current platform ``facts`` modules to supplement native facts information
By parsing semi-structured text into Ansible native data structures, you can take full advantage of Ansible's network modules and plugins.
When not to parse the text
---------------------------
You should not parse semi-structured text when:
- The device, host, or platform has a RESTAPI and returns JSON.
- Existing Ansible facts modules already return the desired data.
- Ansible network resource modules exist for configuration management of the device and resource.
Parsing the CLI
=========================
The ``cli_parse`` module includes the following cli_parsing plugins:
``native``
The native parsing engine built into Ansible and requires no addition python libraries
``xml``
Convert XML to an Ansible native data structure
``textfsm``
A python module which implements a template based state machine for parsing semi-formatted text
``ntc_templates``
Predefined ``textfsm`` templates packages supporting a variety of platforms and commands
``ttp``
A library for semi-structured text parsing using templates, with added capabilities to simplify the process
``pyats``
Uses the parsers included with the Cisco Test Automation & Validation Solution
``json``
Converts JSON output at the CLI to an Ansible native data structure
Although Ansible contains a number of plugins that can convert XML to Ansible native data structures, the ``cli_parse`` module runs the command on devices that return XML and returns the converted data in a single task.
Because ``cli_parse`` uses a plugin based architecture, it can use additional parsing engines from any Ansible collection.
..note::
The ``ansible.netcommon.native`` and ``ansible.netcommon.json`` parsing engines are fully supported with a Red Hat Ansible Automation Platform subscription. Red Hat Ansible Automation Platform subscription support is limited to the use of the ``ntc_templates``, pyATS, ``textfsm``, ``xmltodict``, public APIs as documented.
Parsing with the native parsing engine
--------------------------------------
The native parsing engine is included with the ``cli_parse`` module. It uses data captured using regular expressions to populate the parsed data structure. The native parsing engine requires a YAML template file to parse the command output.
Networking example
^^^^^^^^^^^^^^^^^^
This example uses the output of a network device command and applies a native template to produce an output in Ansible structured data format.
The ``show interface`` command output from the network device looks as follows:
This native parser template is structured as a list of parsers, each containing the following key-value pairs:
-``example`` - An example line of the text line to be parsed
-``getval`` - A regular expression using named capture groups to store the extracted data
-``result`` - A data tree, populated as a template, from the parsed data
-``shared`` - (optional) The shared key makes the parsed values available to the rest of the parser entries until matched again.
The following example task uses ``cli_parse`` with the native parser and the example template above to parse the ``show interface`` command from a Cisco NXOS device:
..code-block:: yaml
- name: "Run command and parse with native"
ansible.netcommon.cli_parse:
command: show interface
parser:
name: ansible.netcommon.native
set_fact: interfaces
Taking a deeper dive into this task:
- The ``command`` option provides the command you want to run on the device or host. Alternately, you can provide text from a previous command with the ``text`` option instead.
- The ``parser`` option provides information specific to the parser engine.
- The ``name`` suboption provides the fully qualified collection name (FQCN) of the parsing engine (``ansible.netcommon.native``).
- The ``cli_parse`` module, by default, looks for the template in the templates directory as ``{{ short_os }}_{{ command }}.yaml``.
- The ``short_os`` in the template filename is derived from either the host ``ansible_network_os`` or ``ansible_distribution``.
- Spaces in the network or host command are replace with ``_`` in the ``command`` portion of the template filename. In this example, the ``show interfaces`` network CLI command becomes ``show_interfaces`` in the filename.
..note::
``ansible.netcommon.native`` parsing engine is fully supported with a Red Hat Ansible Automation Platform subscription.
Lastly in this task, the ``set_fact`` option sets the following ``interfaces`` fact for the device based on the now-structured data returned from ``cli_parse``:
..code-block:: yaml
Ethernet1/1:
hardware: 100/1000/10000 Ethernet
mac_address: 5254.005a.f8bd
name: Ethernet1/1
state:
admin: up
operating: up
Ethernet1/10:
hardware: 100/1000/10000 Ethernet
mac_address: 5254.005a.f8c6
<...>
Linux example
^^^^^^^^^^^^^
You can also use the native parser to run commands and parse output from Linux hosts.
The output of a sample Linux command (``ip addr show``) looks as follows:
..code-block:: bash
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
Create the native template to match this output and store it as ``templates/fedora_ip_addr_show.yaml``:
..code-block:: yaml
---
- example: '1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000'
getval: |
(?x) # free-spacing
\d+:\s # the interface index
(?P<name>\S+):\s # the name
<(?P<properties>\S+)> # the properties
\smtu\s(?P<mtu>\d+) # the mtu
.* # gunk
state\s(?P<state>\S+) # the state of the interface
result:
"{{ name }}":
name: "{{ name }}"
loopback: "{{ 'LOOPBACK' in stats.split(',') }}"
up: "{{ 'UP' in properties.split(',') }}"
carrier: "{{ not 'NO-CARRIER' in properties.split(',') }}"
broadcast: "{{ 'BROADCAST' in properties.split(',') }}"
multicast: "{{ 'MULTICAST' in properties.split(',') }}"
state: "{{ state|lower() }}"
mtu: "{{ mtu }}"
shared: True
- example: 'inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0'
getval: |
(?x) # free-spacing
\s+inet\s(?P<inet>([0-9]{1,3}\.){3}[0-9]{1,3}) # the ip address
/(?P<bits>\d{1,2}) # the mask bits
result:
"{{ name }}":
ip_address: "{{ inet }}"
mask_bits: "{{ bits }}"
..note::
The ``shared`` key in the parser template allows the interface name to be used in subsequent parser entries. The use of examples and free-spacing mode with the regular expressions makes the template easier to read.
The following example task uses ``cli_parse`` with the native parser and the example template above to parse the Linux output:
..code-block:: yaml
- name: Run command and parse
ansible.netcommon.cli_parse:
command: ip addr show
parser:
name: ansible.netcommon.native
set_fact: interfaces
This task assumes you previously gathered facts to determine the ``ansible_distribution`` needed to locate the template. Alternately, you could provide the path in the ``parser/template_path`` option.
Lastly in this task, the ``set_fact`` option sets the following ``interfaces`` fact for the host, based on the now-structured data returned from ``cli_parse``:
..code-block:: yaml
lo:
broadcast: false
carrier: true
ip_address: 127.0.0.1
mask_bits: 8
mtu: 65536
multicast: false
name: lo
state: unknown
up: true
enp64s0u1:
broadcast: true
carrier: true
ip_address: 192.168.86.83
mask_bits: 24
mtu: 1500
multicast: true
name: enp64s0u1
state: up
up: true
<...>
Parsing JSON
-------------
Although Ansible will natively convert serialized JSON to Ansible native data when recognized, you can also use the ``cli_parse`` module for this conversion.
Example task:
..code-block:: yaml
- name: "Run command and parse as json"
ansible.netcommon.cli_parse:
command: show interface | json
parser:
name: ansible.netcommon.json
register: interfaces
Taking a deeper dive into this task:
- The ``show interface | json`` command is issued on the device.
- The output is set as the ``interfaces`` fact for the device.
- JSON support is provided primarily for playbook consistency.
..note::
The use of ``ansible.netcommon.json`` is fully supported with a Red Hat Ansible Automation Platform subscription
Parsing with ntc_templates
----------------------------
The ``ntc_templates`` python library includes pre-defined ``textfsm`` templates for parsing a variety of network device commands output.
Example task:
..code-block:: yaml
- name: "Run command and parse with ntc_templates"
ansible.netcommon.cli_parse:
command: show interface
parser:
name: ansible.netcommon.ntc_templates
set_fact: interfaces
Taking a deeper dive into this task:
- The ``ansible_network_os`` of the device is converted to the ntc_template format ``cisco_nxos``. Alternately, you can provide the ``os`` with the ``parser/os`` option instead.
- The ``cisco_nxos_show_interface.textfsm`` template, included with the ``ntc_templates`` package, parses the output.
- See `the ntc_templates README <https://github.com/networktocode/ntc-templates/blob/master/README.md>`_ for additional information about the ``ntc_templates`` python library.
..note::
Red Hat Ansible Automation Platform subscription support is limited to the use of the ``ntc_templates`` public APIs as documented.
This task and and the predefined template sets the following fact as the ``interfaces`` fact for the host:
..code-block:: yaml
interfaces:
- address: 5254.005a.f8b5
admin_state: up
bandwidth: 1000000 Kbit
bia: 5254.005a.f8b5
delay: 10 usec
description: ''
duplex: full-duplex
encapsulation: ARPA
hardware_type: Ethernet
input_errors: ''
input_packets: ''
interface: mgmt0
ip_address: 192.168.101.14/24
last_link_flapped: ''
link_status: up
mode: ''
mtu: '1500'
output_errors: ''
output_packets: ''
speed: 1000 Mb/s
- address: 5254.005a.f8bd
admin_state: up
bandwidth: 1000000 Kbit
bia: 5254.005a.f8bd
delay: 10 usec
Parsing with pyATS
----------------------
``pyATS`` is part of the Cisco Test Automation & Validation Solution. It includes many predefined parsers for a number of network platforms and commands. You can use the predefined parsers that are part of the ``pyATS`` package with the ``cli_parse`` module.
Example task:
..code-block:: yaml
- name: "Run command and parse with pyats"
ansible.netcommon.cli_parse:
command: show interface
parser:
name: ansible.netcommon.pyats
set_fact: interfaces
Taking a deeper dive into this task:
- The ``cli_parse`` modules converts the ``ansible_network_os`` automatically (in this example, ``ansible_network_os`` set to ``cisco.nxos.nxos``, converts to ``nxos`` for pyATS. Alternately, you can set the OS with the ``parser/os`` option instead.
- Using a combination of the command and OS, the pyATS selects the following parser: https://pubhub.devnetcloud.com/media/genie-feature-browser/docs/#/parsers/show%2520interface.
- The ``cli_parse`` module sets ``cisco.ios.ios`` to ``iosxe`` for pyATS. You can override this with the ``parser/os`` option.
-``cli_parse`` only uses the predefined parsers in pyATS. See the `pyATS documentation <https://developer.cisco.com/docs/pyats/>`_ and the full list of `pyATS included parsers <https://pubhub.devnetcloud.com/media/genie-feature-browser/docs/#/parsers>`_.
..note::
Red Hat Ansible Automation Platform subscription support is limited to the use of the pyATS public APIs as documented.
This task sets the following fact as the ``interfaces`` fact for the host:
..code-block:: yaml
mgmt0:
admin_state: up
auto_mdix: 'off'
auto_negotiate: true
bandwidth: 1000000
counters:
in_broadcast_pkts: 3
in_multicast_pkts: 1652395
in_octets: 556155103
in_pkts: 2236713
in_unicast_pkts: 584259
rate:
in_rate: 320
in_rate_pkts: 0
load_interval: 1
out_rate: 48
out_rate_pkts: 0
rx: true
tx: true
delay: 10
duplex_mode: full
enabled: true
encapsulations:
encapsulation: arpa
ethertype: '0x0000'
ipv4:
192.168.101.14/24:
ip: 192.168.101.14
prefix_length: '24'
link_state: up
<...>
Parsing with textfsm
---------------------
``textfsm`` is a Python module which implements a template-based state machine for parsing semi-formatted text.
The following sample``textfsm`` template is stored as ``templates/nxos_show_interface.textfsm``
..code-block:: text
Value Required INTERFACE (\S+)
Value LINK_STATUS (.+?)
Value ADMIN_STATE (.+?)
Value HARDWARE_TYPE (.\*)
Value ADDRESS ([a-zA-Z0-9]+.[a-zA-Z0-9]+.[a-zA-Z0-9]+)
Value BIA ([a-zA-Z0-9]+.[a-zA-Z0-9]+.[a-zA-Z0-9]+)
The following task uses the example template for ``textfsm`` with the ``cli_parse`` module.
..code-block:: yaml
- name: "Run command and parse with textfsm"
ansible.netcommon.cli_parse:
command: show interface
parser:
name: ansible.netcommon.textfsm
set_fact: interfaces
Taking a deeper dive into this task:
- The ``ansible_network_os`` for the device (``cisco.nxos.nxos``) is converted to ``nxos``. Alternately you can provide the OS in the ``parser/os`` option instead.
- The textfsm template name defaulted to ``templates/nxos_show_interface.textfsm`` using a combination of the OS and command run. Alternately you can override the generated template path with the ``parser/template_path`` option.
- See the `textfsm README <https://github.com/google/textfsm>`_ for details.
-``textfsm`` was previously made available as a filter plugin. Ansible users should transition to the ``cli_parse`` module.
..note::
Red Hat Ansible Automation Platform subscription support is limited to the use of the ``textfsm`` public APIs as documented.
This task sets the following fact as the ``interfaces`` fact for the host:
..code-block:: yaml
- ADDRESS: X254.005a.f8b5
ADMIN_STATE: up
BANDWIDTH: 1000000 Kbit
BIA: X254.005a.f8b5
DELAY: 10 usec
DESCRIPTION: ''
DUPLEX: full-duplex
ENCAPSULATION: ARPA
HARDWARE_TYPE: Ethernet
INPUT_ERRORS: ''
INPUT_PACKETS: ''
INTERFACE: mgmt0
IP_ADDRESS: 192.168.101.14/24
LAST_LINK_FLAPPED: ''
LINK_STATUS: up
MODE: ''
MTU: '1500'
OUTPUT_ERRORS: ''
OUTPUT_PACKETS: ''
SPEED: 1000 Mb/s
- ADDRESS: X254.005a.f8bd
ADMIN_STATE: up
BANDWIDTH: 1000000 Kbit
BIA: X254.005a.f8bd
Parsing with TTP
-----------------
TTP is a Python library for semi-structured text parsing using templates. TTP uses a jinja-like syntax to limit the need for regular expressions. Users familiar with jinja templating may find the TTP template syntax familiar.
admin state is {{ admin_state }}{{ ignore(".\*") }}
The following task uses this template to parse the ``show interface`` command output:
..code-block:: yaml
- name: "Run command and parse with ttp"
ansible.netcommon.cli_parse:
command: show interface
parser:
name: ansible.netcommon.ttp
set_fact: interfaces
Taking a deeper dive in this task:
- The default template path ``templates/nxos_show_interface.ttp`` was generated using the ``ansible_network_os`` for the host and ``command`` provided.
- TTP supports several additional variables that will be passed to the parser. These include:
-``parser/vars/ttp_init`` - Additional parameter passed when the parser is initialized.
-``parser/vars/ttp_results`` - Additional parameters used to influence the parser output.
-``parser/vars/ttp_vars`` - Additional variables made available in the template.
- See the `TTP documentation <https://ttp.readthedocs.io>`_ for details.
The task sets the follow fact as the ``interfaces`` fact for the host:
Although Ansible contains a number of plugins that can convert XML to Ansible native data structures, the ``cli_parse`` module runs the command on devices that return XML and returns the converted data in a single task.
Use the ``command`` suboption for the ``parser`` to configure the command the parser expects if it is different from the command ``cli_parse`` runs:
..code-block:: yaml
- name: "Run command and parse with native"
ansible.netcommon.cli_parse:
command: sho int
parser:
name: ansible.netcommon.native
command: show interface
Provide a custom OS value
--------------------------------
Use the ``os`` suboption to the parser to directly set the OS instead of using ``ansible_network_os`` or ``ansible_distribution`` to generate the template path or with the specified parser engine:
..code-block:: yaml
- name: Use ios instead of iosxe for pyats
ansible.netcommon.cli_parse:
command: show something
parser:
name: ansible.netcommon.pyats
os: ios
- name: Use linux instead of fedora from ansible_distribution
ansible.netcommon.cli_parse:
command: ps -ef
parser:
name: ansible.netcommon.native
os: linux
Parse existing text
--------------------
Use the ``text`` option instead of ``command`` to parse text collected earlier in the playbook.
