goでのec2.DescribeInstancesテストコード

ec2DescribeInstances.go

package main

import (
    "fmt"
    "os"
    "time"
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/aws/ec2metadata"
    "github.com/aws/aws-sdk-go/service/ec2"
)

const timezone = "Asia/Tokyo"

func main() {
    location, err := time.LoadLocation(timezone)
    if err != nil {
        location = time.FixedZone(timezone, 9*60*60)
    }
    time.Local = location
    fmt.Println(time.Now())

    sess := session.Must(session.NewSession())
    svc := ec2metadata.New(sess)

    doc, _ := svc.GetInstanceIdentityDocument()
    instanceId := doc.InstanceID
    region := doc.Region
    fmt.Println(region)
    fmt.Println(instanceId)

    ec2svc := ec2.New(sess, aws.NewConfig().WithRegion(region))

    start := time.Now()
    for remain := 60*18; remain > 0; remain -= 1 {
        now := time.Now()
	fmt.Println(now)
        fmt.Println(now.Sub(start))

	params := &ec2.DescribeInstancesInput{
		    Filters: []*ec2.Filter{
			    {
				    Name:   aws.String("instance-state-name"),
				    Values: []*string{aws.String("running"),},
			    },
		    },
	    }
	instances, err := ec2svc.DescribeInstances(params)
	if err != nil {
	    fmt.Println("there was an error listing instances in", err.Error())
	    os.Exit(1)
	}
	for idx, res := range instances.Reservations {
	    fmt.Println("  > Reservation Id", *res.ReservationId, " Num Instances: ", len(res.Instances))
	    for _, inst := range instances.Reservations[idx].Instances {
		fmt.Println("    - Instance ID: ", *inst.InstanceId)
	    }
	}
        time.Sleep(5*time.Minute)
    }
    end := time.Now()
    fmt.Println(end.Sub(start))
}