Confused about usage with Koa

[robross0606]

I've been trying to get this going with Koa, but I'm unsure how to proceed based on the README. Doing just this as per the README doesn't seem to expose the /metrics endpoint and results in a 404 error:

  const { koaMiddleware } = require('prometheus-api-metrics')
  app.use(koaMiddleware())

Doing this:

  const { koaMiddleware } = require('prometheus-api-metrics')
  const bodyParser = require('koa-bodyparser')
  app.use(bodyParser())
  app.use(koaMiddleware())

Also results in a 404 error.

A more fully fleshed out example would be much appreciated.

[robross0606]

I figured it out. Unlike other middleware which intercepts and exposes /metrics regardless of what we have in our router filters, this one appears to prevent us from doing something like:

  ///Return 404s for all other paths
  apiRouter.get('/(.*)', async ctx => {
    ctx.body = '404: Not found'
    ctx.response.status = 404
  })

We would have to specifically accommodate /metrics in our router config. I'm unclear why this doesn't work when something like @echo-health/koa-prometheus-exporter exposes the endpoint regardless of what we have in the rest of our router config.