AWS dashboard to CSV

main.go

package main

import (
	"encoding/csv"
	"encoding/json"
	"log"
	"net/http"
	"os"
	"strconv"
	"strings"
	"time"
)

var statusURL = "http://status.aws.amazon.com/data.json"
var client = &http.Client{Timeout: 1 * time.Second}

type status struct {
	Archive []*event
}

type event struct {
	RawDate    string `json:"date"`
	RawService string `json:"service"`
	Summary    string `json:"summary"`
}

func (e *event) Date() time.Time {
	i, err := strconv.ParseInt(e.RawDate, 10, 64)
	if err != nil {
		return time.Time{}
	}

	return time.Unix(i, 0)
}

func (e *event) GlobalService() bool {
	return e.RawService == "management-console"
}

func (e *event) Region() string {
	if e.GlobalService() {
		return "global"
	}
	fields := strings.Split(e.RawService, "-")
	return strings.Join(fields[1:], "-")
}

func (e *event) Service() string {
	if e.GlobalService() {
		return e.RawService
	}
	fields := strings.Split(e.RawService, "-")
	return fields[0]
}

func (e *event) HeaderRecord() []string {
	return []string{
		"date",
		"region",
		"service",
		"summary",
	}
}

func (e *event) Record() []string {
	return []string{
		e.Date().Format(time.RFC3339),
		e.Region(),
		e.Service(),
		e.Summary,
	}
}

func run() error {
	s, err := getStatus(statusURL)
	if err != nil {
		return err
	}

	begin, _ := time.Parse(time.RFC3339, "2018-04-01T00:00:00Z")
	end, _ := time.Parse(time.RFC3339, "2018-07-01T00:00:00Z")

	choose := func(e *event) bool {
		if e.Date().IsZero() {
			return false
		}

		if e.Date().Before(begin) || e.Date().After(end) {
			return false
		}
		return true
	}

	w := csv.NewWriter(os.Stdout)
	defer w.Flush()

	for _, record := range filter(s.Archive, choose) {
		if err := w.Write(record.Record()); err != nil {
			log.Print(err)
		}
	}

	return nil
}

type predicate func(*event) bool

func filter(events []*event, p predicate) []*event {
	result := []*event{}
	for _, event := range events {
		if p(event) {
			result = append(result, event)
		}
	}

	return result
}

func getStatus(url string) (*status, error) {
	resp, err := http.Get(url)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	s := &status{}
	err = json.NewDecoder(resp.Body).Decode(s)
	if err != nil {
		return nil, err
	}
	return s, nil
}

func main() {
	err := run()
	if err != nil {
		log.Fatal(err)
	}
}