yamlpyconfig 0.1.4

A unified YAML configuration manager supporting local files and dynamic Nacos configuration with hot-reloading, environment variable substitution, and built-in encryption (SM2/SM4) support.

YAML Configuration Management: Local Files + Nacos Dynamic Configuration

This project provides a unified YAML configuration loading framework that supports both local YAML files and Nacos configuration center, with features such as hot updates, environment variable substitution, and encrypted value decoding.

Install the core package:

pip install yamlpyconfig

If you need Nacos support:

pip install yamlpyconfig[nacos]

---

1. Local YAML Configuration

Your configuration folder (e.g., /config) must contain at least:

• application.yaml
• Optional: application-{profile}.yaml

1.1 Profile Resolution Rules

The active profile is determined with the following priority (from highest to lowest):

1. Environment variable: APP_PROFILE
2. Environment variable: SPRING_PROFILES_ACTIVE
3. The profile field inside application.yaml
4. If none of the above exist → application-{profile}.yaml will NOT be loaded

Notes

1. The configuration directory must contain application.yaml. Missing this file causes an error.
2. If a profile is resolved but application-{profile}.yaml does not exist, an exception is raised.

---

2. Loading Configuration from Nacos

To enable Nacos, declare the config-sources.nacos section inside your local configuration:

config-sources:
  nacos:
    server-addr: "192.168.30.36:9090"
    namespace: "dev"
    group: "DEFAULT_GROUP"
    username: "nacos"
    password: "{encrypted}VuFvNZOg/q7ZQoIUGWydBw=="
    imports:
      - data-id: "gateway.yaml"
      - data-id: "application-ext.yaml"

2.1 Configuration Merge Priority (Low → High)

1. Local application.yaml
2. Local application-{profile}.yaml
3. Nacos imports (following the order declared; later entries override earlier ones)

---

3. Key Features and Usage Examples

3.1 Basic Usage

Example: load configuration and print updates automatically:

@pytest.mark.asyncio
async def test_config_manager_with_nacos(self):
    async with ConfigManager("./") as config_manager:
        logger.info(config_manager.get_config())
        while True:
            await asyncio.sleep(5)
            logger.info(config_manager.get_config())

When entering the async with block:

• Local configuration is loaded first
• If Nacos is configured → it connects automatically and listens for real-time updates

---

3.2 Environment Variable Interpolation

Local YAML files support Spring-style placeholders:

key-with-default: ${KEY1:DEFAULT_VALUE}
key: ${KEY2}

Behavior:

• If the environment variable exists → its value is used
• If it does not exist → use the default value after the colon
• If no default value is provided → None is returned

---

3.3 Encrypted Field Support (SM2 / SM4)

Sensitive fields (passwords, secret keys, etc.) can be encrypted and marked with the {encrypted} prefix:

password: "{encrypted}VuFvNZOg/q7ZQoIUGWydBw=="

To enable automatic decryption, specify the algorithm and key when initializing ConfigManager:

@pytest.mark.asyncio
async def test_config_manager_with_nacos_decrypt(self):

    # SM4 example — uses a symmetric key
    async with ConfigManager(
        "./",
        crypto_algorithm=AlgorithmEnum.SM4,
        key="lSU543Tes6wmjnb+PMVQNg=="
    ) as config_manager:

        logger.info(config_manager.get_config())

Explanation:

• SM4 → symmetric encryption (pass the secret key)
• SM2 → asymmetric encryption (provide the private key; public key optional depending on use case)