main.go

package main

import (
	"encoding/json"
	"flag"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strings"
	"time"
)

type collector struct{}

const minutesBeforeCheck = 55 * time.Minute

var (
	d []Count
	lastChecked time.Time
)

func (c collector) Describe(ch chan<- *prometheus.Desc) {
}

func (c collector) Collect(ch chan<- prometheus.Metric) {
	if len(d) == 0 || time.Now().After(lastChecked.Add(minutesBeforeCheck)) {
		d = CallAPI()
		lastChecked = time.Now()
	}

	for _, m := range d {
		ch <- prometheus.MustNewConstMetric(
			prometheus.NewDesc(prometheus.BuildFQName("circleci", "deploys", "per_day"), "deploys per day", []string{"date"}, nil),
			prometheus.CounterValue,
			float64(m.Deploys),
			m.Date,
		)
	}
}

type Response struct {
	NextPageToken string  `json:"next_page_token"`
	Items         []Items `json:"items"`
}

type Items struct {
	Id          string    `json:"id"`
	Status      string    `json:"status"`
	Duration    int       `json:"duration"`
	CreatedAt   time.Time `json:"created_at"`
	StoppedAt   time.Time `json:"stopped_at"`
	CreditsUsed int       `json:"credits_used"`
}

type Count struct {
        Date    string
        Deploys int
}

func CallAPI() []Count {

	c := []Count{}
	now := time.Now()
	start := now.AddDate(0, 0, -14)
	for d := start; d.After(now) == false; d = d.AddDate(0, 0, 1) {
		c = append(c, Count{d.Format("01-02-2006 Mon"), 0})
	}

	urls := os.Getenv("URL")
	if urls != "" {
		for _, u := range strings.Split(urls, ", ") {
			req, _ := http.NewRequest("GET", u, nil)
			token := "Basic " + os.Getenv("AUTH_TOKEN")
			req.Header.Set("Authorization", token)

			client := new(http.Client)
			resp, _ := client.Do(req)

			body, err := ioutil.ReadAll(resp.Body)
			defer resp.Body.Close()
			if err != nil {
				log.Fatal(err)
			}

			apiResponse := Response{}
			jsonErr := json.Unmarshal(body, &apiResponse)
			if jsonErr != nil {
				log.Fatal(jsonErr)
			}

			for _, m := range apiResponse.Items {
				i := contains(c, m.CreatedAt.Format("01-02-2006 Mon"))
				if i != -1 {
					c[i].Deploys = c[i].Deploys + 1
				}
			}
		}
	}
	return c
}

func contains(s []Count, e string) int {
	for i, a := range s {
		if a.Date == e {
			return i
		}
	}
	return -1
}

var addr = flag.String("listen-address", ":9179", "The address to listen on for HTTP requests.")

func main() {
	flag.Parse()

	var c collector
	prometheus.MustRegister(c)

	http.Handle("/metrics", promhttp.Handler())
	log.Fatal(http.ListenAndServe(*addr, nil))
}