koa-hot-shots
StatsD route monitoring middleware for koa This middleware can be used either globally or on a per-route basis (preferred) and sends status codes and response times to StatsD.
Forked from withspectrum/koa-hot-shots for usage in Short.io
Installation
npm install @short.io/koa-hot-shots
Usage
An example of an koa server with koa-hot-shots:
const koa = require('koa');
const route = require('koa-route');
const statsd = require('@short.io/koa-hot-shots');
const app = new Koa();
app.use(statsd());
app.use(route.get('/', function (ctx) {
ctx.body = 'Hello World!';
});
app.listen(3000);
By default, the middleware will send status_code
and response_time
stats
for all requests. For example, using the created server above and a request to
http://localhost:3000/
, the following stats will be sent:
status_code.200:1|c
response_time:100|ms
Per route example
However, it's highly recommended that you set req.statsdKey
which
will be used to namespace the stats. Be aware that stats will only be logged
once a response has been sent; this means that req.statsdKey
can be
set even after the koa-hot-shots middleware was added to the chain. Here's an
example of a server set up with a more specific key:
var koa = require('koa');
var koaStatsd = require('@short.io/koa-hot-shots');
var app = koa();
function statsd (path) {
return async (ctx, next) => {
const method = req.method || 'unknown_method';
ctx.request.statsdKey = ['http', method.toLowerCase(), path].join('.');
await next();
};
}
app.use(koaStatsd());
app.get('/', statsd('home'), function (ctx) {
ctx.body = 'Hello World!';
});
app.listen(3000);
A GET request to /
on this server would produce the following stats:
http.get.home.status_code.200:1|c
http.get.home.response_time:100|ms
Tags
You can set the tags of the metrics with the req.statsdTags
property.
function statsd (path) {
return async (ctx, next) => {
const method = ctx.request.method || 'unknown_method';
req.statsdKey = ['http', method.toLowerCase(), path].join('.');
req.statsdTags = {
server: process.env.SERVER_NAME,
}
await next();
};
}
These will be sent with both the response time and status code metrics.
Options
koaStatsd(options);
- options
Object
- Container for settings- client
HotShots instance
- a custom hot shots instance - hotShots
Object
- The hotShots options if you don't want to provide your own instance - requestKey
String
- The key on thereq
object at which to grab the key for the statsd logs. Defaults toreq.statsdKey
.
- client