Mock ConfigMap Mount Environment Variables in Python

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.isfile(file_path):
            with open(file_path, "r") as f:
                config[filename] = f.read().strip()
    return config

def create_env_from_config(config):
    """Set environment variables from the loaded config."""
    for key, value in config.items():
        os.environ[key] = value
    return {key: os.environ[key] for key in config}

if __name__ == "__main__":
    # Create a temporary directory to simulate a ConfigMap mount
    with tempfile.TemporaryDirectory() as tmpdir:
        with open(os.path.join(tmpdir, "DATABASE_URL"), "w") as f:
            f.write("postgres://user:pass@localhost:5432/db")
        with open(os.path.join(tmpdir, "LOG_LEVEL"), "w") as f:
            f.write("INFO")
        with open(os.path.join(tmpdir, "MAX_RETRIES"), "w") as f:
            f.write("5")

        # Load config and set environment variables
        config = load_config_from_mount(tmpdir)
        env_vars = create_env_from_config(config)

        print("Environment variables set from ConfigMap mount:")
        for key, value in sorted(env_vars.items()):
            print(f"  {key}={value}")

        # Example of mocking for testing (without actual mount)
        with patch.dict(os.environ, {}, clear=True):
            with patch.object(os, "listdir", return_value=["TEST_KEY"]):
                with patch("builtins.open") as mock_open:
                    mock_open.return_value.__enter__.return_value.read.return_value = "mock_value"

                    fake_config = load_config_from_mount("/fake/mount")
                    print("\nMocked ConfigMap mount result:")
                    print(f"  {fake_config}")