ha_do.go

package main

import (
	"flag"
	"log"
	"strings"

	"github.com/Preetam/libab/go/ab"
	"github.com/digitalocean/godo"
	"golang.org/x/oauth2"
)

type tokenSource string

func (s tokenSource) Token() (*oauth2.Token, error) {
	return &oauth2.Token{AccessToken: string(s)}, nil
}

var node *ab.Node
var client *godo.Client

var dropletID int
var floatingIP string

type handler struct{}

func (h handler) OnAppend(round uint64, commit uint64, data string) {}
func (h handler) OnCommit(round uint64, commit uint64)              {}
func (h handler) LostLeadership()                                   {}
func (h handler) OnLeaderChange(leaderID uint64)                    {}

func (h handler) GainedLeadership() {
	client.FloatingIPActions.Assign(floatingIP, dropletID)
}

func main() {
	flag.IntVar(&dropletID, "droplet-id", 0, "droplet ID")
	addr := flag.String("addr", "", "listen address")
	clusterSize := flag.Int("cluster-size", 3, "cluster size")
	peers := flag.String("peers", "", "comma-separated list of peers")
	flag.StringVar(&floatingIP, "floating-ip", "", "floating IP address")
	token := flag.String("token", "", "DigitalOcean token")
	flag.Parse()

	var err error
	node, err = ab.NewNode(uint64(dropletID), *addr, handler{}, *clusterSize)
	if err != nil {
		log.Fatal(err)
	}
	for _, peer := range strings.Split(*peers, ",") {
		node.AddPeer(peer)
	}
	oauthClient := oauth2.NewClient(oauth2.NoContext,
		tokenSource(*token))
	client = godo.NewClient(oauthClient)
	node.Run()
}