docker error connecting bug

main.go

package main

import (
	"fmt"

	dockerclient "github.com/docker/engine-api/client"
	dockerTypes "github.com/docker/engine-api/types"
	dockerCTypes "github.com/docker/engine-api/types/container"
	dockerNTypes "github.com/docker/engine-api/types/network"
	"golang.org/x/net/context"
)

func main() {
	defaultHeaders := map[string]string{"User-Agent": "engine-api-cli-1.0"}
	dc, err := dockerclient.NewClient("unix:///var/run/docker.sock", "v1.23", nil, defaultHeaders)
	if err != nil {
		panic(err)
	}

	bg := context.Background()
	i := 0
	s := 0

	nr, err := dc.NetworkCreate(bg, "t2", dockerTypes.NetworkCreate{})
	if err != nil {
		panic(err)
	}
	defer func(id string) {
		err := dc.NetworkRemove(bg, id)
		if err != nil {
			panic(err)
		}
	}(nr.ID)

	for {
		err := func() error {
			i++
			r, err := dc.ContainerCreate(bg,
				&dockerCTypes.Config{
					Image:      "alpine",
					Entrypoint: []string{"/bin/sleep", "600"},
				},
				&dockerCTypes.HostConfig{},
				&dockerNTypes.NetworkingConfig{
					EndpointsConfig: map[string]*dockerNTypes.EndpointSettings{
						// Using nr.ID fails most of the time
						nr.ID: {},
						// Using the network name succeeds always
						//"t2": {},
					},
				},
				"")
			if err != nil {
				panic(err)
			}

			err = dc.ContainerStart(bg, r.ID, dockerTypes.ContainerStartOptions{})
			if err != nil {
				return err
			}

			err = dc.ContainerKill(bg, r.ID, "")
			if err != nil {
				panic(err)
			}

			err = dc.ContainerRemove(bg, r.ID, dockerTypes.ContainerRemoveOptions{})
			if err != nil {
				panic(err)
			}
			return nil
		}()
		if err == nil {
			s++
		}
		fmt.Printf("%v of %v succeeded\n", s, i)
	}
}