Add support import

[jimmyxian]

Implement swarm import (issue: docker-archive/classicswarm#631), need this interface
Test code:

package main

import (
    "github.com/samalba/dockerclient"
    "os"
    "fmt"
    "io/ioutil"
)

func main() {
    // Init the client
    docker, _ := dockerclient.NewDockerClient("unix:///var/run/docker.sock", nil)

    file, _ := os.Open("/home/busybox.tar")
    reader, _ := docker.ImportImage("", "mybusybox", "abc", file)

    data, _ := ioutil.ReadAll(reader)
    fmt.Printf("%s", data)
}

Test Result:

[root@localhost samalba]# go run test.go 
{"status":"b14b8a22f2e03d1ac7c4dff8ce73fc763ec158dcfbc86fcc9090a205b5e4bc69"}
[root@localhost samalba]# 
[root@localhost samalba]# docker images
REPOSITORY                         TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
mybusybox                          abc                 b14b8a22f2e0        3 seconds ago       2.43 MB

Signed-off-by: Xian Chaobo xianchaobo@huawei.com

[jimmyxian]

ping @vieux @ehazlett @aluzzardi

[aluzzardi]

What's the difference between this and doRequest? Can the two be refactored so they share most of the same code?

[jimmyxian]

doStreamRequest: the input and output is using io.Reader and io.Writer. it can work streamly.
doRequest: the input and output is byte[]. if we send a request, we have to wait all the response. it can not work streamly.

[jimmyxian]

ping @aluzzardi
Updated by the comments

[donhcd]

nit: use nil instead of []byte{}?

[donhcd]

LGTM after addressing nit

[jimmyxian]

ping @donhcd @aluzzardi
Modified it and check again,thks

[donhcd]

👍

[donhcd]

ping @vieux @abronan @aluzzardi @ehazlett

[aluzzardi]

LGTM

[vieux]

LGTM