ec2.go

package main

import (
        "flag"
        "fmt"
        "log"
        "net/url"
        "strings"

        "github.com/aws/aws-sdk-go/aws"
        "github.com/aws/aws-sdk-go/aws/credentials"
        "github.com/aws/aws-sdk-go/service/ec2"
)

var profile = flag.String("profile", "default", "profile name in aws shared credentials file")
var instanceType = flag.Bool("instance-type", false, "show instance type(e.g. 'c4.large')")

func main() {
        flag.Parse()

        svc := ec2.New(&aws.Config{
                Credentials: credentials.NewSharedCredentials("", *profile),
                Region:      aws.String("ap-northeast-1"),
        })
        filters := []*ec2.Filter{&ec2.Filter{
                Name: aws.String("instance-state-name"),
                Values: []*string{
                        aws.String("running"),
                },
        }}
        resp, err := svc.DescribeInstances(&ec2.DescribeInstancesInput{
                Filters: filters,
        })
        if err != nil {
                log.Fatal(err)
        }
        var lines [][]string
        for _, res := range resp.Reservations {
                for _, inst := range res.Instances {
                        if inst.PublicIpAddress == nil {
                                continue
                        }

                        name := "None"
                        for _, keys := range inst.Tags {
                                if *keys.Key == "Name" {
                                        name = url.QueryEscape(*keys.Value)
                                        break
                                }
                        }
                        values := []string{
                                *inst.PublicIpAddress,
                                *inst.PrivateIpAddress,
                                name,
                                *inst.KeyName,
                        }
                        if *instanceType {
                                values = append(values, *inst.InstanceType)
                        }
                        lines = append(lines, values)
                }
        }

        for _, line := range lines {
                fmt.Println(strings.Join(line, "\t"))
        }
}