main.go

package main

import (
	"context"
	"fmt"
	"net/netip"

	// "flag"

	"log"
	"net"
	"os"
	"os/signal"
	"sync"

	"github.com/cybertec-postgresql/vip-manager/checker"
	"github.com/cybertec-postgresql/vip-manager/ipmanager"
	"github.com/cybertec-postgresql/vip-manager/vipconfig"
)

var (
	// vip-manager version definition
	version = "2.0.0"
)

func getMask(vip netip.Addr, mask int) net.IPMask {
	if mask > 0 || mask < 33 {
		return net.CIDRMask(mask, 32)
	}
	var ip net.IP = vip.AsSlice()
	return ip.DefaultMask()
}

func getNetIface(iface string) *net.Interface {
	netIface, err := net.InterfaceByName(iface)
	if err != nil {
		log.Fatalf("Obtaining the interface raised an error: %s", err)
	}
	return netIface
}

func main() {
	if (len(os.Args) > 1) && (os.Args[1] == "--version") {
		//			log.Print("version " + version)
		//			return nil, nil
		//		}
		fmt.Printf("version: %s\n", version)
		return
	}

	conf, err := vipconfig.NewConfig()
	if err != nil {
		log.Fatal(err)
	}

	lc, err := checker.NewLeaderChecker(conf)
	if err != nil {
		log.Fatalf("Failed to initialize leader checker: %s", err)
	}

	vip := netip.MustParseAddr(conf.IP)
	vipMask := getMask(vip, conf.Mask)
	netIface := getNetIface(conf.Iface)
	states := make(chan bool)
	manager, err := ipmanager.NewIPManager(
		conf.HostingType,
		&ipmanager.IPConfiguration{
			VIP:        vip,
			Netmask:    vipMask,
			Iface:      *netIface,
			RetryNum:   conf.RetryNum,
			RetryAfter: conf.RetryAfter,
		},
		states,
		conf.Verbose,
	)
	if err != nil {
		log.Fatalf("Problems with generating the virtual ip manager: %s", err)
	}

	mainCtx, cancel := context.WithCancel(context.Background())

	go func() {
		c := make(chan os.Signal, 1)
		signal.Notify(c, os.Interrupt)
		<-c
		log.Print("Received exit signal")
		cancel()
	}()

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		err := lc.GetChangeNotificationStream(mainCtx, states)
		if err != nil && err != context.Canceled {
			log.Fatalf("Leader checker returned the following error: %s", err)
		}
		wg.Done()
	}()

	wg.Add(1)
	go func() {
		manager.SyncStates(mainCtx, states)
		wg.Done()
	}()

	wg.Wait()
}