Golang New Examples

Example #1

File: unix_uid_pool_test.go Project: vito/warden-docker

package uid_pool_test

import (
	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"

	"github.com/cloudfoundry-incubator/warden-linux/linux_backend/uid_pool"
)

var _ = Describe("Unix UID pool", func() {
	Describe("acquiring", func() {
		It("returns the next available UID from the pool", func() {
			pool := uid_pool.New(10000, 5)

			uid1, err := pool.Acquire()
			Expect(err).ToNot(HaveOccurred())

			uid2, err := pool.Acquire()
			Expect(err).ToNot(HaveOccurred())

			Expect(uid1).To(Equal(uint32(10000)))
			Expect(uid2).To(Equal(uint32(10001)))
		})

		Context("when the pool is exhausted", func() {
			It("returns an error", func() {
				pool := uid_pool.New(10000, 5)

				for i := 0; i < 5; i++ {
					_, err := pool.Acquire()
					Expect(err).ToNot(HaveOccurred())

Example #2

File: main.go Project: vito/warden-docker

func main() {
	flag.Parse()

	maxProcs := runtime.NumCPU()
	prevMaxProcs := runtime.GOMAXPROCS(maxProcs)

	log.Println("set GOMAXPROCS to", maxProcs, "was", prevMaxProcs)

	if *binPath == "" {
		log.Fatalln("must specify -bin with linux backend")
	}

	if *depotPath == "" {
		log.Fatalln("must specify -depot with linux backend")
	}

	if *rootFSPath == "" {
		log.Fatalln("must specify -rootfs with linux backend")
	}

	uidPool := uid_pool.New(uint32(*uidPoolStart), uint32(*uidPoolSize))

	_, ipNet, err := net.ParseCIDR(*networkPool)
	if err != nil {
		log.Fatalln("error parsing CIDR:", err)
	}

	networkPool := network_pool.New(ipNet)

	// TODO: use /proc/sys/net/ipv4/ip_local_port_range by default (end + 1)
	portPool := port_pool.New(uint32(*portPoolStart), uint32(*portPoolSize))

	runner := linux_command_runner.New(*debug)

	quotaManager, err := quota_manager.New(*depotPath, *binPath, runner)
	if err != nil {
		log.Fatalln("error creating quota manager:", err)
	}

	if *disableQuotas {
		quotaManager.Disable()
	}

	graphDriver, err := graphdriver.New(*graphRoot)
	if err != nil {
		log.Fatalln("error constructing graph driver:", err)
	}

	graph, err := graph.NewGraph(*graphRoot, graphDriver)
	if err != nil {
		log.Fatalln("error constructing graph:", err)
	}

	reg, err := registry.NewRegistry(nil, nil, *dockerRegistry)
	if err != nil {
		log.Fatalln(err)
	}

	pool := container_pool.New(
		*binPath,
		*depotPath,
		*rootFSPath,
		repository_fetcher.Retryable{repository_fetcher.New(reg, graph)},
		graphDriver,
		uidPool,
		networkPool,
		portPool,
		strings.Split(*denyNetworks, ","),
		strings.Split(*allowNetworks, ","),
		runner,
		quotaManager,
	)

	systemInfo := system_info.NewProvider(*depotPath)

	backend := linux_backend.New(pool, systemInfo, *snapshotsPath)

	log.Println("setting up backend")

	err = backend.Setup()
	if err != nil {
		log.Fatalln("failed to set up backend:", err)
	}

	log.Println("starting server; listening with", *listenNetwork, "on", *listenAddr)

	graceTime := *containerGraceTime

	wardenServer := server.New(*listenNetwork, *listenAddr, graceTime, backend)

	err = wardenServer.Start()
	if err != nil {
		log.Fatalln("failed to start:", err)
	}

	signals := make(chan os.Signal, 1)

	go func() {
		<-signals
		log.Println("stopping...")
		wardenServer.Stop()
		os.Exit(0)
	}()

	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)

	select {}
}