Stats - Go middleware to collect HTTP stats

Features

Stats Middleware that can be plugged into your http stack
Collects HTTP request and repsponse stats with default implementation.
Support to provide your own implementation of stats collection to suit your application needs
HttpHandler that serves "/stats" endpoint.
build on top of coda-hale's metrics library - http://github.com/codahale/metrics
Outputs metrics in Influxdb Line protocol, JSON, Graphite format. (Currently only supports influxdb line protocol: https://github.com/influxdata/influxdb/blob/master/tsdb/README.md)
Examples to demonstrate application and request level metrics collection.
github.com/supershal/stats/metrics package can be used to collect metrics for non-http apps. For example, Database stats can be collected using metrics package.

Installation

Install Go Version >=1.5.1
Make sure you have installed git, hg etc.
Your workspace is setup with GOPATH. http://golang.org/doc/code.html
Download it:
```
go get github.com/supershal/stats
```

GoDoc

Usage

HTTP middleware provided to collect stats. Currently it supports alice and Negroni(https://github.com/codegangsta/negroni) compatible middlewares. However, its very easy to create your own middleware function for your framework.(Checkout middleware.go)

Add HttpStats middleware in your HTTP app

Following example is using 'alice' middleware chaining. Checkout /example for more details.

		func middlewares() alice.Chain {
			host, _ := os.Hostname()
			tags := map[string]string{
			"host": host,
		}
		s := stats.NewHTTPStats(tags)
		return alice.New(s.HTTPStatsHandler)
		}

Serve metrics on separate HTTP server.

		stats.ServeMetrics(5555, "/metrics")

A metric collector agent collectd or telegraf can invoke localhost:5555/metrics periodically and send metrics back to TSDB (influxdb or graphite).

Output Influxdb example

https://github.com/influxdata/influxdb/blob/master/tsdb/README.md

http_request,host=localhost,foo=bar GET=10
http_request,host=localhost,foo=bar POST=5 
http_response,host=localhost,foo=bar 200=5
http_response,host=localhost,foo=bar 503=2
http_response,host=localhost,foo=bar 403=3
http_response,host=localhost,foo=bar total=10
http_response,host=localhost,foo=bar latency.P50=10
http_response,host=localhost,foo=bar latency.P75=15
http_response,host=localhost,foo=bar latency.P90=20
http_response,host=localhost,foo=bar latency.P95=25
http_response,host=localhost,foo=bar latency.P99=40
http_response,host=localhost,foo=bar latency.P999=50