Spring Config Client for Python

A lightweight Python client for Spring Cloud Config Server. Load your centralized configuration into Python applications at startup.

Why This Exists

Spring Cloud Config Server is great for centralized configuration management, but Python clients were either outdated or overcomplicated. This library does one thing well: fetch configuration from your Spring Config Server and load it into your application's environment.

Installation

pip install spring-config-client-python

Quick Start

from spring_config_client import SpringConfigClient
import os

# Initialize and load config at application startup
client = SpringConfigClient(
    server_url="https://config.example.com",
    app_name="my-python-service",
    profile="production",
    username="config-admin",  # optional, for basic auth
    password="secret"          # optional
)

# Fetch and load all configuration into os.environ
config = client.fetch_and_load()

# Access your configuration
db_host = os.environ.get('DB_HOST')
api_key = os.environ.get('API_KEY')

How It Works

1. Fetches configuration from Spring Config Server using the standard API endpoint: /{application}/{profile}
2. Merges multiple property sources with correct precedence (profile-specific overrides defaults)
3. Interpolates property placeholders like ${DB_HOST} from existing environment variables
4. Loads everything into os.environ as-is (including dotted keys like spring.datasource.url)

Configuration Keys

Your Spring Config Server can return keys in any format:

• Environment variable style: DATABASE_URL, API_KEY
• Spring property style: spring.datasource.url, logging.level.root
• Mixed: Whatever you configure in your .properties or .yml files

All keys are loaded as-is into os.environ. No transformation, no magic.

Property Interpolation

The client supports Spring-style property placeholders:

# In your Spring Config Server
DATABASE_URL=postgresql://${DB_HOST}:${DB_PORT}/mydb

The client will resolve ${DB_HOST} and ${DB_PORT} from your existing environment variables.

Features

• ✅ Loads configuration at startup (no runtime refresh)
• ✅ Basic authentication support
• ✅ Property placeholder interpolation (${VAR})
• ✅ Correct property source precedence
• ✅ Zero dependencies except requests
• ✅ Works with Spring Cloud Config Server 2025.0.0

What This Library Does NOT Do

• ❌ Runtime configuration refresh - load once at startup only
• ❌ Encryption/decryption - use Spring Config Server's encryption features
• ❌ Advanced retry logic - fails fast if server is unreachable
• ❌ Configuration validation - that's your application's responsibility

This is intentional. Keep it simple.

Example with Docker

FROM python:3.11-slim

ENV CONFIG_SERVER_URL=https://config.example.com
ENV CONFIG_APP_NAME=my-service
ENV CONFIG_PROFILE=production

COPY . /app
WORKDIR /app

RUN pip install spring-config-client-python

CMD python app.py

# app.py
import os
from spring_config_client import SpringConfigClient

# Load config from environment
client = SpringConfigClient(
    server_url=os.environ['CONFIG_SERVER_URL'],
    app_name=os.environ['CONFIG_APP_NAME'],
    profile=os.environ['CONFIG_PROFILE']
)

client.fetch_and_load()

# Your application code here

Error Handling

The client fails fast if the config server is unreachable. This is by design - your service shouldn't start without proper configuration.

try:
    client.fetch_and_load()
except requests.RequestException as e:
    print(f"Failed to load configuration: {e}")
    sys.exit(1)

Requirements

• Python 3.9+
• Spring Cloud Config Server 2025.0.0 (or compatible versions)

License

MIT

Contributing

Found a bug? Have a feature request? Open an issue on GitHub.

Keep it simple. This library does one thing well and that's enough.