ansible.utils.fact_diff module – Find the difference between currently set facts

Note

This module is part of the ansible.utils collection (version 2.7.0).

You might already have this collection installed if you are using the ansible package. It is not included in ansible-core. To check whether it is installed, run ansible-galaxy collection list.

To install it, use: ansible-galaxy collection install ansible.utils.

To use it in a playbook, specify: ansible.utils.fact_diff.

New in ansible.utils 1.0.0

Synopsis

  • Compare two facts or variables and get a diff.

Note

This module has a corresponding action plugin.

Parameters

Parameter

Comments

after

any / required

The second fact to be used in the comparison.

before

any / required

The first fact to be used in the comparison.

plugin

dictionary

Configure and specify the diff plugin to use

Default: {}

name

string

The diff plugin to use, in fully qualified collection name format.

Default: "ansible.utils.native"

vars

dictionary

Parameters passed to the diff plugin.

Default: {}

skip_lines

list / elements=string

Skip lines matching these regular expressions.

Matches will be removed prior to the diff.

If the provided before and after are a string, they will be split.

Each entry in each list will be cast to a string for the comparison

Examples

- ansible.builtin.set_fact:
    before:
      a:
        b:
          c:
            d:
            - 0
            - 1
    after:
      a:
        b:
          c:
            d:
            - 2
            - 3

- name: Show the difference in json format
  ansible.utils.fact_diff:
    before: "{{ before }}"
    after: "{{ after }}"

# TASK [ansible.utils.fact_diff] **************************************
# --- before
# +++ after
# @@ -3,8 +3,8 @@
#          "b": {
#              "c": {
#                  "d": [
# -                    0,
# -                    1
# +                    2,
# +                    3
#                  ]
#              }
#          }
#
# changed: [localhost]

- name: Show the difference in path format
  ansible.utils.fact_diff:
    before: "{{ before|ansible.utils.to_paths }}"
    after: "{{ after|ansible.utils.to_paths }}"

# TASK [ansible.utils.fact_diff] **************************************
# --- before
# +++ after
# @@ -1,4 +1,4 @@
#  {
# -    "a.b.c.d[0]": 0,
# -    "a.b.c.d[1]": 1
# +    "a.b.c.d[0]": 2,
# +    "a.b.c.d[1]": 3
#  }
#
# changed: [localhost]

- name: Show the difference in yaml format
  ansible.utils.fact_diff:
    before: "{{ before|to_nice_yaml }}"
    after: "{{ after|to_nice_yaml }}"

# TASK [ansible.utils.fact_diff] **************************************
# --- before
# +++ after
# @@ -2,5 +2,5 @@
#      b:
#          c:
#              d:
# -            - 0
# -            - 1
# +            - 2
# +            - 3

# changed: [localhost]


#### Show the difference between complex object using restconf
#  ansible_connection: ansible.netcommon.httpapi
#  ansible_httpapi_use_ssl: True
#  ansible_httpapi_validate_certs: False
#  ansible_network_os: ansible.netcommon.restconf

- name: Get the current interface config prior to changes
  ansible.netcommon.restconf_get:
    content: config
    path: /data/Cisco-NX-OS-device:System/intf-items/phys-items
  register: pre

- name: Update the description of eth1/100
  ansible.utils.update_fact:
    updates:
    - path: "pre['response']['phys-items']['PhysIf-list'][{{ index }}]['descr']"
      value: "Configured by ansible {{ 100 | random }}"
  vars:
    index: "{{ pre['response']['phys-items']['PhysIf-list']|ansible.utils.index_of('eq', 'eth1/100', 'id') }}"
  register: updated

- name: Apply the configuration
  ansible.netcommon.restconf_config:
    path: 'data/Cisco-NX-OS-device:System/intf-items/'
    content: "{{ updated.pre.response}}"
    method: patch

- name: Get the current interface config after changes
  ansible.netcommon.restconf_get:
    content: config
    path: /data/Cisco-NX-OS-device:System/intf-items/phys-items
  register: post

- name: Show the difference
  ansible.utils.fact_diff:
    before: "{{ pre.response|ansible.utils.to_paths }}"
    after: "{{ post.response|ansible.utils.to_paths }}"

# TASK [ansible.utils.fact_diff] *********************************************
# --- before
# +++ after
# @@ -3604,7 +3604,7 @@
#      "phys-items['PhysIf-list'][37].bw": "0",
#      "phys-items['PhysIf-list'][37].controllerId": "",
#      "phys-items['PhysIf-list'][37].delay": "1",
# -    "phys-items['PhysIf-list'][37].descr": "Configured by ansible 95",
# +    "phys-items['PhysIf-list'][37].descr": "Configured by ansible 20",
#      "phys-items['PhysIf-list'][37].dot1qEtherType": "0x8100",
#      "phys-items['PhysIf-list'][37].duplex": "auto",
#      "phys-items['PhysIf-list'][37].id": "eth1/100",

# changed: [nxos101]

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key

Description

diff_lines

list / elements=string

The diff_text split into lines.

Returned: always

diff_text

string

The diff in text format.

Returned: always

Authors

  • Bradley Thornton (@cidrblock)