Koa-Beatrix

This module provides a koa middleware that runs requests in a beatrix (RabbitMQ) queue.

Requests are therefore automatically rate-limited, fault-resilient, and distributed.

Example

const Koa = require('koa');
const app = new Koa();

const KoaBeatrix = require('koa-beatrix');
const Queues = KoaBeatrix(app, {
    prefix: 'myapp',
    beatrix: {
        // standard beatrix options
    },
    concurrency: 3 // default queue options may be included here
})

app.use(Queues.queue('example', {
    // standard queue creation options
    concurrency: 5, // overrides the default
    maxAttempts: 3,
    delay: 1
}));

// following middleware will be run inside the queue `myapp.example`
app.use((ctx, next) => {
    ctx.body = 'ok'
})

Usage

KoaBeatrix(app, config) => {queue: Function, beatrix: Beatrix}

app must be a Koa instance. config should be an object containing any of the following optional parameters:

beatrix - either a Beatrix instance, or a Beatrix options object. If it doesn't exist it looks on app.context.beatrix prefix = String - an optional prefix for all queues in this group nameFromPath = Boolean - if true, queue names are taken from prefix+path like "myapp.index" onSuccess(ctx, result) - called when a job completes within the allowed time with the ctx of the request and the result of the job as {status, body, headers}. Defaults to sending the result as-is. onError(ctx, err) - called when a job fails all retries within the allowed time with the ctx of the request and the error object. Defaults to status=500 and sending the message of the error as the body. onTimeout(ctx) - called when a job does not complete/fail before the allowed time of the request. Defaults to status=202

config may also include any standard Beatrix Queue parameters such as maxAttempts, bypass, replyTimeout

KoaBeatrix().queue(name, config) => middleware

name is required unless nameFromPath is true config will override any config from the KoaBeatrix() call The returned middleware can be used in a router or directly on the app