pit.yaml

"value-domain":
  "domain"    : DOMAIN
  "password"  : PASSWORD

value-domain-check.go

package main

import (
	"fmt"
	"github.com/typester/go-pit"
	"io/ioutil"
	"log"
	"net"
	"net/http"
)

type PitSetting struct {
	Domain   string
	Password string
}

type Record struct {
	Domain string
	Ip     string
}

func GetPitData(data string) (*PitSetting, error) {
	vd, err := pit.Get(data, pit.Requires{})
	if err != nil {
		return nil, err
	}
	p := new(PitSetting)

	p.Domain = (*vd)["domain"]
	if p.Domain == "" {
		log.Fatalln("no such domain")
	}
	p.Password = (*vd)["password"]
	if p.Password == "" {
		log.Fatalln("no such password")
	}
	return p, nil
}

func GetCurrentIP() (string, error) {
	response, err := http.Get("http://temple-kun.appspot.com/")
	if err != nil {
		return "", err
	}
	defer response.Body.Close()

	contents, err := ioutil.ReadAll(response.Body)
	if err != nil {
		return "", err
	}
	return string(contents), nil
}

func GetDomainIP(domain string, subDomains []string) ([]Record, error) {
	records := make([]Record, 0, len(subDomains))

	for _, subDomain := range subDomains {
		s := subDomain + "." + domain
		v, err := net.LookupHost(s)
		if err != nil {
			return nil, err
		}
		records = append(records, Record{s, v[0]})
	}
	return records, nil
}

func main() {
	pitDomain := "value-domain"
	subDomains := []string{"www", "www2", "www3"}

	pit, err := GetPitData(pitDomain)
	if err != nil {
		log.Fatal(err)
	}

	currentIpAddr, err := GetCurrentIP()
	if err != nil {
		log.Fatal(err)
	}

	records, err := GetDomainIP(pit.Domain, subDomains)
	if err != nil {
		log.Fatal(err)
	}

	for i := range subDomains {
		fmt.Printf("domain : %s\ndomain  IP : %s\ncurrent IP : %s\n",
			records[i].Domain,
			records[i].Ip,
			currentIpAddr,
		)

		if records[i].Ip == currentIpAddr {
			fmt.Println("STATUS : same\n")
			continue
		} else {
			fmt.Println("STATUS : not equal")
			url := fmt.Sprintf("http://dyn.value-domain.com/cgi-bin/dyn.fcg?d=%s&p=%s&h=%s&i=%s",
				pit.Domain,
				pit.Password,
				subDomains[i],
				currentIpAddr,
			)
			fmt.Println(url)

			response, err := http.Get(url)
			if err != nil {
				log.Fatal(err)
			}
			defer response.Body.Close()

			contents, err := ioutil.ReadAll(response.Body)
			if err != nil {
				log.Fatal(err)
			}
			log.Println(string(contents))
		}
	}
}