12.7 Module Utils
In this short lab we will have a look on how to move reusable code from modules into module utils.
Task 1 - Create a Module Utils for file handling
In the last lab, we created a simple module that allows us to track the cat’s state on every host by writing it to a file in /tmp/.cat_state.txt.
To do so we wrote two functions in the module to write and read the cat state from the file.
Let’s create a module util for file handling operations called state_file_utils.py and move the functions there.
Solution Task 1
Create the moduel_utils/state_file_utils.py file with the following content:
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| # Copyright: (c) 2025, Your Name <your@email.ch>
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
from typing import Optional
CAT_STATE_FILE_PATH: str = "/tmp/.cat_state.txt"
def read_cat_state() -> Optional[str]:
"""
Get the previous cat state from the file.
"""
try:
with open(CAT_STATE_FILE_PATH, "r") as f:
return f.read().strip()
except (IOError, FileNotFoundError):
return None
def write_cat_state(cat_state: str) -> None:
"""
Write the cat state to the file.
"""
with open(CAT_STATE_FILE_PATH, "w") as f:
f.write(cat_state)
|
Now import it in the training.labs.schroedingers_cat module and update the code:
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| ...
from ansible.module_utils.basic import AnsibleModule
from ansible_collections.training.labs.plugins.module_utils.state_file_utils import (
read_cat_state,
write_cat_state,
)
import random
from typing import Optional
def run_module() -> None:
...
previous_cat_state: Optional[str] = read_cat_state()
...
if previous_cat_state != new_cat_state or previous_cat_state is None:
...
if not module.check_mode:
write_cat_state(new_cat_state)
...
|
All done?
- Can you add unit tests to the module utils?