stinger-python-utils 0.1.4

Common utilities for Stinger Python services.

stinger-python-utils

Shared utilities for Stinger Python services, providing convenient message creation for MQTT communication.

Installation

uv add stinger-python-utils

MessageCreator

MessageCreator is a utility class for creating MQTT messages with standardized properties and payloads.

Basic Usage

from pydantic import BaseModel
from stinger_python_utils.message_creator import MessageCreator

class MyPayload(BaseModel):
    name: str
    value: int

payload = MyPayload(name="test", value=42)
message = MessageCreator.signal_message("my/topic", payload)

Methods

Method	Purpose	Return Code
signal_message(topic, payload)	Send a signal with one-time delivery	QoS 1, no retain
status_message(topic, payload, expiry_seconds)	Send status that expires	QoS 1, retained, with expiry
error_response_message(topic, return_code, correlation_id, debug_info)	Error response to a request	QoS 1, user properties: ReturnCode
response_message(topic, payload, return_code, correlation_id)	Successful response to a request	QoS 1, user properties: ReturnCode
property_state_message(topic, payload, state_version)	Publish property state	QoS 1, retained, JSON content type
property_update_request_message(topic, payload, version, response_topic, correlation_id)	Request property update	QoS 1, user property: PropertyVersion
property_response_message(topic, payload, version, return_code, correlation_id, debug_info)	Respond to property update	QoS 1, user properties: ReturnCode, PropertyVersion
request_message(topic, payload, response_topic, correlation_id)	Send a request (auto-generates UUID if no correlation_id)	QoS 1, auto correlation ID

Example: Request/Response Pattern

from pydantic import BaseModel
from stinger_python_utils.message_creator import MessageCreator

class Request(BaseModel):
    action: str

request = Request(action="start")
msg = MessageCreator.request_message(
    "devices/cmd",
    request,
    response_topic="devices/response"
)
# Returns a Message with auto-generated correlation ID

Example: Error Response

msg = MessageCreator.error_response_message(
    "devices/response",
    return_code=500,
    correlation_id="req-123",
    debug_info="Device not found"
)
# User properties include: ReturnCode=500, DebugInfo=Device not found