ansible-cheat-sheet.md

How to use the ansible debugger

[192.0.2.10] TASK: install package (debug)> p task
TASK: install package
[192.0.2.10] TASK: install package (debug)> p task.args
{u'name': u'{{ pkg_name }}'}
[192.0.2.10] TASK: install package (debug)> p task_vars
{u'ansible_all_ipv4_addresses': [u'192.0.2.10'],
 u'ansible_architecture': u'x86_64',
 ...
}
[192.0.2.10] TASK: install package (debug)> p task_vars['pkg_name']
u'bash'
[192.0.2.10] TASK: install package (debug)> p host
192.0.2.10
[192.0.2.10] TASK: install package (debug)> p result._result
{'_ansible_no_log': False,
 'changed': False,
 u'failed': True,
 ...
 u'msg': u"No package matching 'not_exist' is available"}
 
 [192.0.2.10] TASK: install package (debug)> p task.args
{u'name': u'{{ pkg_name }}'}
[192.0.2.10] TASK: install package (debug)> task.args['name'] = 'bash'
[192.0.2.10] TASK: install package (debug)> p task.args
{u'name': 'bash'}
[192.0.2.10] TASK: install package (debug)> redo

How to upload a file from local machine to servers

- name: my file upload
  copy:
    src: file_in_files_folder_of_my_role.tar.gz # placing under files folder is the relevant part here
    dest: /opt/or_somewhere_else_on_server.tar.gz
    mode: '0444' # optional
  become: yes # optional

How to create a folder

- name: create a directory
  file:
    path: /opt/my_path
    state: directory
    mode: 0755
    owner: <user>
    group: <user_group>
  become: yes # optional

How to get facts of all hosts when playing with 'serial: 1'

---
- name: Gather facts from all hosts
  hosts: all
  gather_facts: true

- name: Do something sequentially
  hosts: all
  gather_facts: false
  serial: 1

  roles:
    # in this role the facts of all hosts will be available
    # e.g. all ips, hostnames etc.
    - role: my_sequential_role # e.g. rke2 install

How to get all fqdns for jinja templating

{% for host in groups['all'] %}
  {% if hostvars[host]['ansible_fqdn'] is defined %}
    "{{ hostvars[host]['ansible_fqdn'] }}"
  {% endif %}
{% endfor %}

How to dump task_vars from the ansible debugger to a file?

Intended for the use in a debugger session that was started with strategy=debug or debugger: on_failed etc. This is great to further process the dump to json content. See ansible_debugger_json_converter.py for more on that.

Simple vars dump

This will not be proper json formatted filecontent.

with open('file.json', 'w') as f: f.write(str(task_vars)); f.close();

Quick & Dirty variant

This will process the content and remove the raw file right away.

with open('file.json', 'w') as f: f.write(str(task_vars)); f.close(); os.system('python3 ansible_debugger_json_converter.py -i file.json'); os.remove('file.json');

ansible_debugger_json_converter.py

import json
import ast
import argparse
import os

def convert_to_json(input_file, output_file):
    """
    Intended use for ansible debugger variable dumping.
    Convert a Python dictionary string in a file to a JSON file.

    Args:
    input_file (str): Path to the file containing the Python dictionary string.
    output_file (str): Path to the output JSON file.

    This function reads a file containing a Python dictionary string, safely evaluates
    the string to a Python dictionary, and then writes it to a JSON file.
    """

    print(f"Reading from {input_file} and writing to {output_file}")

    # Read the content of the file
    try:
        with open(input_file, 'r') as file:
            file_content = file.read()
    except IOError as e:
        print(f"Error reading file: {e}")
        return

    # Strip the outer double quotes
    file_content = file_content.strip('"')

    # Safely evaluate the string to a Python dictionary
    try:
        dict_content = ast.literal_eval(file_content)
    except ValueError as e:
        print(f"Error in converting to dictionary: {e}")
        return

    # Write the dictionary back to a file in JSON format
    try:
        with open(output_file, 'w') as file:
            json.dump(dict_content, file, indent=4)
        print(f"File successfully written to {output_file}")
    except IOError as e:
        print(f"Error writing file: {e}")
        return

def main():
    """
    Main function to handle command line arguments and invoke the conversion.

    This script accepts command line arguments for input and optional output file paths.
    If the output file path is not provided, the script generates the output file name
    by appending '_clean' to the input file name.
    """

    # Create argument parser
    parser = argparse.ArgumentParser(description='Convert a file from Python dictionary string to JSON.')
    parser.add_argument('-i', '--input_file', required=True, help='Input file path')
    parser.add_argument('-o', '--output_file', help='Output JSON file path')

    # Parse arguments
    args = parser.parse_args()

    # Determine the output file name
    if args.output_file:
        output_file = args.output_file
    else:
        # Append '_clean' to the input file name (before the extension)
        base, ext = os.path.splitext(args.input_file)
        output_file = f"{base}_clean{ext}"

    # Convert and save
    convert_to_json(args.input_file, output_file)

if __name__ == "__main__":
    main()