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How to Audit Environment Variable Files for Missing Values in Python
A Python tool that reads an environment variable file and reports any variables with empty or missing values.
import os
import re
from pathlib import Path
def audit_env_file(filepath: str) -> None:
"""
Audit an environment variable file for missing values.
Prints file status and lists variables that have empty values.
"""
path = Path(filepath)
if not path.exists():
print(f"Error: File '{filepa…
How to Run an Integration Test with Docker Compose Mock in Python
Run a Python integration test against a docker-compose environment, using mocks to simulate service health and business logic responses.
import subprocess
import json
from typing import Dict
def run_integration_test() -> Dict[str, str]:
"""
Simulates an integration test against a docker-compose environment
using a mock service that returns canned responses.
"""
# Mock docker-compose environment check
env_ready = subprocess.run(…
How to Mock Environment Variables in Python
A context manager that injects and restores environment variables for isolated testing of config-dependent code.
import os
class EnvInjector:
def __init__(self, mock_vars=None):
self.mock_vars = mock_vars or {}
self.original = {}
def __enter__(self):
for key, value in self.mock_vars.items():
if key in os.environ:
self.original[key] = os.environ[key]
os.env…
How to Mock Environment Variables in Python for 12-Factor Config
Read 12-factor config from env vars and test/mock them with unittest.mock.patch.dict without touching the real environment.
import os
import json
from unittest.mock import patch
def load_config(env_prefix="APP"):
"""Read 12-factor style config from env vars"""
required = ["DATABASE_URL", "API_KEY"]
optional = {"PORT": "8080", "DEBUG": "false"}
config = {}
for key in required:
full_key = f"{env_prefix}_{key…
How to Simulate Blue-Green Deployment Switch in Python
A mock Blue-Green deployment class that deploys new versions to an inactive environment, runs a health check, switches traffic, and supports rollback in Python.
import random
import time
class BlueGreenDeployment:
def __init__(self, initial_env="blue"):
self.environments = {"blue": "v1.0", "green": "v1.0"}
self.active_env = initial_env
self.running = True
def deploy_new_version(self, version, target_env):
if target_env == self.active_…
Mock ConfigMap Mount Environment Variables in Python
Simulate reading environment variables from a Kubernetes ConfigMap-mounted directory and test it with mocks.
import os
import tempfile
from unittest.mock import patch
def load_config_from_mount(mount_path):
"""Simulate reading environment variables from a ConfigMap-mounted directory."""
config = {}
for filename in os.listdir(mount_path):
file_path = os.path.join(mount_path, filename)
if os.path.i…
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