nacos-toolkit 0.1.1

Nacos configuration parsing and management tool

nacos-toolkit

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An AI-native Python toolkit for Nacos configuration parsing and management.

Highlights

• AI-Native — Ships with llms.txt for instant agent comprehension, letting AI coding assistants understand and use the API without reading source code
• Agent-Ready — AGENTS.md guides AI contributors on architecture, data flow, and conventions
• Template Engine — ${VAR} syntax with dot-notation, recursive resolution, and cycle protection
• Deep Merge — Merge multiple YAML/JSON configs with intuitive dict-merge and array-replace semantics
• Async Nacos Client — Fetch, cache, and listen for config changes from Nacos server
• Zero Config — Sensible defaults, works out of the box with a single function call

Installation

uv add nacos-toolkit

Or with pip:

pip install nacos-toolkit

Quick Start

Fetch Config from Nacos

import asyncio
from nacos_toolkit import get_nacos_config

async def main():
    result = await get_nacos_config(
        connection={
            "server_addr": "nacos-server:8848",
            "namespace": "production",
            "username": "nacos",
            "password": "nacos",
        },
        base_configs=[
            {"data_id": "common.yml", "group": "DEFAULT_GROUP"},
            {"data_id": "app.yml", "group": "DEFAULT_GROUP"},
        ],
    )
    print(result["config"])

asyncio.run(main())

How it works:

1. Fetches all base_configs in order
2. Shallow-merges them into a single variable context
3. Processes only the last config, rendering ${VAR} templates against the merged context
4. Auto-injects DEPLOY_ENV = namespace

With Override Config

result = await get_nacos_config(
    connection={...},
    base_configs=[
        {"data_id": "common.yml", "group": "DEFAULT_GROUP"},
        {"data_id": "app.yml", "group": "DEFAULT_GROUP"},
    ],
    override_config={
        "data_id": "app-customized.yml",
        "group": "DEFAULT_GROUP",
    },
)

The override config is deep-merged on top of the base config. Override values take precedence.

Debug Mode

result = await get_nacos_config(
    connection={...},
    base_configs=[...],
    debug=True,
)
print(result["config"])  # Processed config
print(result["raw"])     # Merged raw config (before template rendering)

Config Processing

Process YAML/JSON Configs

from nacos_toolkit import NacosConfigUtils, NacosParser

# Process YAML config (default format)
config = NacosConfigUtils.process_configuration(
    """
    server:
      host: ${HOST}
      port: ${PORT}
    database:
      url: ${DB_HOST}:3306
    """,
    external_vars={
        "HOST": "localhost",
        "PORT": "8080",
        "DB_HOST": "mysql-server",
    },
)
# config = {"server": {"host": "localhost", "port": "8080"}, "database": {"url": "mysql-server:3306"}}

# Process JSON config
config = NacosConfigUtils.process_configuration(
    '{"name": "${APP_NAME}"}',
    fmt=NacosParser.JSON,
    external_vars={"APP_NAME": "my-app"},
)

Template features:

• ${VAR} syntax
• Dot-notation nested references: ${redis.hostname}
• Recursive template resolution: ${URL} -> ${PROTO}://${HOST} -> https://example.com
• Max resolution depth of 5 to prevent infinite loops
• Undefined variables are left as-is: ${UNKNOWN}

Merge Custom Config

base = {"host": "localhost", "port": 3000, "cors": {"whitelist": ["http://a.com"]}}

merged = NacosConfigUtils.process_and_merge_custom_config(
    base,
    """
    port: 9999
    cors:
      whitelist:
        - http://b.com
        - http://c.com
    """,
)
# merged = {"host": "localhost", "port": 9999, "cors": {"whitelist": ["http://b.com", "http://c.com"]}}

Merge rules:

• Dicts are deep-merged
• Arrays are replaced entirely (no element-level merge)
• Custom config can reference base config variables

Auto-convert Comma-separated Strings to Arrays

By default, comma-separated strings in cors.whitelist are converted to arrays:

config = NacosConfigUtils.process_configuration(
    "cors:\n  whitelist: 'http://a.com, http://b.com'"
)
# config["cors"]["whitelist"] = ["http://a.com", "http://b.com"]

# Custom fields to convert
config = NacosConfigUtils.process_configuration(
    "tags: 'a, b, c'",
    convert_array_fields=["tags"],
)
# config["tags"] = ["a", "b", "c"]

YAML array values are preserved as-is and not re-processed.

Config Listener

from nacos_toolkit import setup_config_listener

def on_update(content: str):
    print(f"Config updated: {content}")

setup_config_listener(
    nacos_config={
        "server_addr": "nacos-server:8848",
        "namespace": "production",
        "username": "nacos",
        "password": "nacos",
    },
    listen_requests=[
        {"data_id": "app.yml", "group": "DEFAULT_GROUP"},
    ],
    callback=on_update,
)

When no callback is provided, the cached config is updated automatically.

Local Config Files

from nacos_toolkit import get_local_config, find_local_config, parse_config_file

# Auto-discover and parse (priority: .json -> .yaml -> .yml)
config = get_local_config(file_name="app", file_path="./config")

# Find file path only
path = find_local_config(file_name="app", file_path="./config")
# path = "/abs/path/config/app.yml" or None

# Parse a specific file
config = parse_config_file(file_path="/path/to/config.yml")

Low-level Utilities

from nacos_toolkit import NacosConfigUtils, ConfigMerger, TemplateEngine

# Deep merge
merged = ConfigMerger.merge({"a": 1, "b": {"x": 1}}, {"b": {"y": 2}, "c": 3})
# {"a": 1, "b": {"x": 1, "y": 2}, "c": 3}

# Nested property access
val = NacosConfigUtils.get_nested_property({"a": {"b": {"c": 42}}}, "a.b.c")
# 42

# Nested property set
obj = {}
NacosConfigUtils.set_nested_property(obj, "a.b.c", 42)
# obj = {"a": {"b": {"c": 42}}}

# Template detection
TemplateEngine.contains_template("${HOST}")  # True
TemplateEngine.contains_template("plain")    # False

Development

# Install dependencies
uv sync

# Run tests
uv run pytest -v

# Lint
uv run ruff check .

API Reference

Function / Class	Description
await get_nacos_config(...)	Fetch and process config from Nacos
setup_config_listener(...)	Listen for Nacos config changes
get_local_config(...)	Read local config files
NacosConfigUtils.process_configuration()	Parse config + render templates
NacosConfigUtils.process_and_merge_custom_config()	Process and merge custom config
NacosConfigUtils.merge_configurations()	Deep-merge two configs
NacosConfigUtils.contains_template()	Check if string contains templates
NacosConfigUtils.convert_string_fields_to_arrays()	Convert comma strings to arrays
NacosConfigUtils.get_nested_property()	Get nested property by dot path
NacosConfigUtils.set_nested_property()	Set nested property by dot path
find_local_config(...)	Find local config file path
parse_config_file(...)	Parse JSON/YAML file
NacosParser.YAML / .JSON	Config format enum

License

MIT