monitor deploy hash on aws

gistfile1.txt

package main

import (
	"encoding/json"
	"fmt"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/ec2"
	"io/ioutil"
	"net"
	"net/http"
	"sync"
	"time"
)

var wg sync.WaitGroup

func main() {
	stats := make(map[string][]string)
	svc := ec2.New(&aws.Config{Region: aws.String("us-east-1")})

	resp, err := svc.DescribeInstances(nil)
	if err != nil {
		panic(err)
	}

	for idx, _ := range resp.Reservations {
		for _, inst := range resp.Reservations[idx].Instances {
			for _, t := range inst.Tags {
				if *t.Key == "Name" {
					wg.Add(1)
					stats[*t.Value] = appendHash(stats[*t.Value], *inst.PublicDnsName)
				}
			}
		}
	}
	wg.Wait()
	str, _ := json.Marshal(stats)
	fmt.Println(string(str))
}

func appendHash(hashes []string, publicDnsName string) []string {
	defer wg.Done()

	if hashes == nil {
		hashes = []string{}
	}
	url := "http://" + publicDnsName + "/debug/vars"
	fmt.Println("url: " + url)
	req, _ := http.NewRequest("GET", url, nil)
	tr := http.Transport{
		Dial: func(network, addr string) (net.Conn, error) {
			timeout := 2 * time.Second
			return net.DialTimeout(network, addr, timeout)
		},
	}
	tr.ResponseHeaderTimeout = 2 * time.Second
	res, err := tr.RoundTrip(req)
	if err != nil {
		fmt.Println(err.Error())
		return hashes
	}
	str, err := ioutil.ReadAll(res.Body)
	defer res.Body.Close()
	if err != nil {
		fmt.Println(err.Error())
		return hashes
	}
	var obj map[string]interface{}
	json.Unmarshal(str, &obj)

	if obj["DeployHashKey"] != nil {
		hash := obj["DeployHashKey"].(string)
		hashes = append(hashes, hash)
	}

	return hashes
}