kubemq 4.1.4

KubeMQ Python SDK - Production-grade messaging with async support, pub/sub, queues, and commands/queries

KubeMQ Python SDK

Description

KubeMQ is an enterprise-grade message broker for containers, designed for any workload and architecture running in Kubernetes. This SDK provides a production-ready Python client supporting all KubeMQ messaging patterns: Events (pub/sub), Events Store (persistent pub/sub), Queues (with ack/reject), Commands, and Queries (RPC).

Table of Contents

• Installation
• Quick Start
  • Send and Receive Events
• Messaging Patterns
  • Events
  • Events Store
  • Queues
  • Commands
  • Queries
• Configuration
• Error Handling
• Troubleshooting
• Security
• Additional Resources
• Contributing
• License

Installation

Requires Python 3.11+.

pip install kubemq

For optional features:

pip install kubemq[docs]    # API reference generation
pip install kubemq[otel]    # OpenTelemetry integration

Quick Start

Prerequisites: Python 3.11+, KubeMQ server running at localhost:50000 (install KubeMQ)

Send and Receive Events

Send an event:

from kubemq import PubSubClient, EventMessage

with PubSubClient(address="localhost:50000") as client:
    client.publish_event(
        EventMessage(channel="quickstart", body=b"Hello KubeMQ!")
    )
    print("Event sent!")

Subscribe to events:

import time
from kubemq import PubSubClient, EventsSubscription, CancellationToken

def on_event(event):
    print(f"Received: {event.body.decode('utf-8')}")

with PubSubClient(address="localhost:50000") as client:
    client.subscribe_to_events(
        subscription=EventsSubscription(
            channel="quickstart",
            on_receive_event_callback=on_event,
            on_error_callback=lambda e: print(f"Error: {e}"),
        ),
        cancel=CancellationToken(),
    )
    time.sleep(60)  # Keep listening

See also: Queues Quick Start | RPC Quick Start

Messaging Patterns

Pattern	Delivery Guarantee	Use When	Example Use Case
Events	At-most-once	Fire-and-forget broadcasting to multiple subscribers	Real-time notifications, log streaming
Events Store	At-least-once (persistent)	Subscribers must not miss messages, even if offline	Audit trails, event sourcing, replay
Queues	At-least-once (with ack)	Work must be processed exactly by one consumer with acknowledgment	Job processing, task distribution
Commands	At-most-once (request/reply)	You need a response confirming the action was executed	Device control, configuration changes
Queries	At-most-once (request/reply)	You need to retrieve data from a responder	Data lookups, service-to-service reads

Events

Fire-and-forget pub/sub. Use PubSubClient (sync) or AsyncPubSubClient (async). View examples →

Events Store

Persistent pub/sub with replay. Subscribers can start from a sequence number, timestamp, or receive only new messages. View examples →

Queues

Pull-based message queues with acknowledgment, reject, requeue, dead-letter queues, and delayed delivery. View examples →

Commands

Request/reply where the sender expects confirmation of execution (no response payload). View examples →

Queries

Request/reply where the sender expects a data response. View examples →

Configuration

Option	Type	Default	Description
address	str	"localhost:50000"	KubeMQ server gRPC address
client_id	str	hostname	Unique client identifier
auth_token	str	""	Authentication token
tls	TLSConfig	disabled	TLS configuration (cert, key, CA files)
max_send_size	int	104857600	Maximum send message size in bytes
max_receive_size	int	104857600	Maximum receive message size in bytes
auto_reconnect	bool	True	Auto-reconnect on connection loss
reconnect_interval_seconds	int	1	Seconds between reconnect attempts
log_level	int | None	None (no logging)	Python logging level

All clients accept these options as constructor arguments:

from kubemq import PubSubClient, TLSConfig

client = PubSubClient(
    address="kubemq-server:50000",
    client_id="my-service",
    auth_token="your-token",
    tls=TLSConfig(
        enabled=True,
        cert_file="/path/to/cert.pem",
        key_file="/path/to/key.pem",
        ca_file="/path/to/ca.pem",
    ),
)

Error Handling

All SDK errors extend KubeMQError:

from kubemq import (
    PubSubClient, EventMessage,
    KubeMQError, KubeMQConnectionError, KubeMQTimeoutError,
)

try:
    with PubSubClient(address="localhost:50000") as client:
        client.publish_event(
            EventMessage(channel="ch1", body=b"hello")
        )
except KubeMQConnectionError as e:
    print(f"Connection failed: {e}")
except KubeMQTimeoutError as e:
    print(f"Operation timed out: {e}")
except KubeMQError as e:
    print(f"KubeMQ error: {e}")

See the Troubleshooting Guide for solutions to common errors.

Troubleshooting

Problem	Solution
Connection refused	Ensure KubeMQ is running: docker run -p 50000:50000 kubemq/kubemq-community
Authentication failed	Verify auth_token matches server configuration
Channel not found	Create the channel first or enable auto-create on the server
Timeout / deadline exceeded	Increase timeout_in_seconds or check network latency
No messages received	Verify subscriber is connected before sender publishes

→ Full Troubleshooting Guide (11+ entries)

Security

See SECURITY.md for vulnerability reporting. The SDK supports TLS and mTLS connections — for configuration details, see How to Connect with TLS.

Additional Resources

• KubeMQ Documentation — Official KubeMQ documentation and guides
• API Reference — Auto-generated API documentation
• Full Documentation Index — Complete SDK documentation index
• KubeMQ Concepts — Core KubeMQ messaging concepts
• SDK Feature Parity Matrix — Cross-SDK feature comparison
• CHANGELOG.md — Release history
• TROUBLESHOOTING.md — Common issues and solutions
• Examples — Runnable code examples for all patterns

Contributing

Contributions are welcome! See CONTRIBUTING.md for development setup, coding standards, and pull request guidelines.

License

This project is licensed under the MIT License — see the LICENSE file for details.