mqi - Rust API's for IBM MQ

Introduction

The mqi crate provides idiomatic Rust APIs for the IBM® MQ Interface (MQI) and MQ Administration Interface (MQAI). IBM MQ is an enterprise-grade message queuing system that enables reliable, secure, and asynchronous data exchange between applications, systems, and services.

This crate enables Rust developers to interact with IBM MQ servers, leveraging the powerful and stable IBM MQ libraries.

Key Features

• MQI Integration: Connect to IBM MQ servers to send and receive messages synchronously using robust MQI functions.
• MQAI Administration: Administer IBM MQ servers through the comprehensive MQAI functions.
• Cross Platform: Supports Windows, MacOS, and Linux.
• Stability: Built on the libmqm-sys crate, ensuring reliable connectivity to MQ queue managers using the IBM-supplied libraries.

Usage

1. Download and install the client from IBM:

   • Windows/Linux x86-64 redistributable - https://public.dhe.ibm.com/ibmdl/export/pub/software/websphere/messaging/mqdev/redist/
   • MacOS (x86-64/ARM64) toolkit - https://public.dhe.ibm.com/ibmdl/export/pub/software/websphere/messaging/mqdev/mactoolkit/
   • Linux (x86-64/ARM64/PowerPC64le/S390X) MQ Advanced Developer - https://public.dhe.ibm.com/ibmdl/export/pub/software/websphere/messaging/mqadv/

2. Extract and install the MQ client in any location.

3. Set the MQ_HOME environment variable to the installed location.

4. Add the mqi crate to your project:

   cargo add mqi
   

5. Ensure the MQ libraries are in the library search path. On Linux, this can be achieved by setting the LD_LIBRARY_PATH environment variable.

An easy way of running an MQ server for development and testing is to run the IBM supplied docker container:

docker run -d --publish 1414:1414 icr.io/ibm-messaging/mq:latest

Refer to https://github.com/ibm-messaging/mq-container/blob/master/docs/usage.md

Example

Connect to the default queue manager using the MQSERVER environment variable with username and password authentication.

use std::error::Error;

use mqi::{
    connection::{Credentials, ThreadNone},
    prelude::*,
    types::{ApplName, QueueName},
};

fn main() -> Result<(), Box<dyn Error>> {
    const TARGET: QueueName = QueueName(mqstr!("DEV.QUEUE.1"));

    // User credentials and application name.
    // MQI will use the C API defaults, referring to MQSERVER environment variable if set.
    let connect_options = (
        ApplName(mqstr!("readme_example")),
        Credentials::User("user", "password".into()),
    );

    // Connect to the queue manager. Make all MQ warnings as a rust Result::Err
    let queue_manager = mqi::connect::<ThreadNone>(&connect_options).warn_as_error()?;

    // Put a single string message on the target queue. Discard any warnings.
    queue_manager.put_message(&TARGET, &(), "Hello").discard_warning()?;

    // Queue manager disconnect - this also happens automatically on Drop.
    queue_manager.disconnect().discard_warning()?;

    Ok(())
}

Refer to the examples folder for comprehensive examples that cover reading and putting messages to a queue, using transactions and working with topics.

Goals

• Expose an ergonomic API over the IBM MQI libraries.
• Become the preferred API for developing MQ applications where performance and safety is the primary concern.
• Provide a simple and comprehensive layer over IBM MQ to connect, send and receive MQ messages, whilst still allowing developers to tweak the advanced options that the MQI library provides.
• Utilise Rust features such as lifetimes, safety guarantees, strong type system and invariants for a robust API.

Feature flags

Version Compatibility

• The current MSRV is 1.87. No MSRV policy has been established.
• IBM MQ client support is in line with IBM's support for MQ client. This crate supports IBM MQ client 9.2 to 9.4. Version specific features can be enabled using the mqc_* feature flags.

Status

This library is under heavy development. The velocity of change to the API is high and is likely to evolve. See the progress page for the progress on the list of MQI functions exposed.

Support

There are no guarantees of compatibility with any future versions of the crate; the API is subject to change based on feedback and enhancements. Relentless refactoring may occur before a stable crate is released.

This crate is provided as-is with no guarantees of support or updates.

This crate is not approved, endorsed, acknowledged, or supported by IBM. You cannot use IBM formal support channels (Cases/PMRs) for assistance on the use of this crate.

Contributions

All feedback, suggestions, contributions and enhancements are welcome.

License

Licensed under

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)