技術書典5: Githubを使ったMackerelの運用管理 / Githubを使用した実例（２） / インシデント管理システムの構築 / Lambdaファンクション

main.go

package main

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"os"
	"time"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/kms"
	"github.com/google/go-github/github"
	"golang.org/x/oauth2"
)

type Roles struct {
	Fullname    string `json:"fullname"`
	ServiceName string `json:"serviceName"`
	ServiceUrl  string `json:"serviceUrl"`
	RoleName    string `json:"roleName"`
	RoleUrl     string `json:"roleUrl"`
}

type Host struct {
	Id        string  `json:"id"`
	Name      string  `json:"name"`
	Url       string  `json:"url"`
	Type      string  `json:"type"`
	Status    string  `json:"status"`
	Memo      string  `json:"memo"`
	IsRetired bool    `json:"isRetired"`
	Roles     []Roles `json:"roles"`
}

type Alert struct {
	CreatedAt         int64   `json:"createdAt"`
	WarningThreshold  float64 `json:"warningThreshold"`
	CriticalThreshold float64 `json:"criticalThreshold"`
	Duration          int     `json:"duration"`
	IsOpen            bool    `json:"isOpen"`
	MetricLabel       string  `json:"metricLabel"`
	MetricValue       float64 `json:"metricValue"`
	MonitorName       string  `json:"monitorName"`
	MonitorOperator   string  `json:"monitorOperator"`
	Status            string  `json:"status"`
	Trigger           string  `json:"trigger"`
	Url               string  `json:"url"`
}

type Notification struct {
	OrgName string `json:"orgName"`
	Event   string `json:"event"`
	Host    Host   `json:"host"`
	Alert   Alert  `json:"alert"`
}

const (
	layout   = "2006-01-02 15:04:05 MST"
	timezone = "Asia/Tokyo"
)

var owner string = os.Getenv("OWNER")
var repository string = os.Getenv("REPOSITORY")
var encToken string = os.Getenv("TOKEN")
var decToken string

func init() {
	kmsClient := kms.New(session.New())
	decodedBytes, err := base64.StdEncoding.DecodeString(encToken)
	if err != nil {
		panic(err)
	}
	input := &kms.DecryptInput{
		CiphertextBlob: decodedBytes,
	}
	response, err := kmsClient.Decrypt(input)
	if err != nil {
		panic(err)
	}
	decToken = string(response.Plaintext[:])
}

func handleRequest(ctx context.Context, request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
	var notification Notification
	json.Unmarshal([]byte(request.Body), &notification)

	// Ignore notification of recovery
	if notification.Alert.Status == "ok" {
		return events.APIGatewayProxyResponse{Body: "ok", StatusCode: 200}, nil
	}

	/* debug
	for key, value := range request.Headers {
		fmt.Printf("    %s: %s\n", key, value)
	}
	fmt.Println(request.Body)
	*/

	gctx := context.Background()
	ts := oauth2.StaticTokenSource(
		&oauth2.Token{AccessToken: decToken},
	)
	tc := oauth2.NewClient(ctx, ts)

	client := github.NewClient(tc)

	status := notification.Alert.Status
	host := notification.Host.Name
	monitor := notification.Alert.MonitorName
	url := notification.Alert.Url

	utc := time.Unix(notification.Alert.CreatedAt/1000, 0)
	location, _ := time.LoadLocation(timezone)
	jst := utc.In(location)
	creatAt := fmt.Sprintf("%s", jst.Format(layout))

	title := fmt.Sprintf("[%s] Host:%s, Monitor:%s", status, host, monitor)
	body := fmt.Sprintf("Time: %s\nUrl: %s", creatAt, url)

	opt := &github.IssueRequest{
		Title: &title,
		Body:  &body,
	}
	client.Issues.Create(gctx, owner, repository, opt)

	return events.APIGatewayProxyResponse{Body: request.Body, StatusCode: 200}, nil
}

func main() {
	lambda.Start(handleRequest)
}