Add a build package (#1926)

* Add a build package

* fix go mod

* package tar

build/docker/docker.go

@@ -0,0 +1,96 @@
+// Package docker builds docker images
+package docker
+
+import (
+	"archive/tar"
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	docker "github.com/fsouza/go-dockerclient"
+	"github.com/micro/go-micro/v3/build"
+	"github.com/micro/go-micro/v3/logger"
+)
+
+type dockerBuild struct {
+	Options build.Options
+	Client  *docker.Client
+}
+
+func (d *dockerBuild) Package(name string, s *build.Source) (*build.Package, error) {
+	image := name
+
+	buf := new(bytes.Buffer)
+	tw := tar.NewWriter(buf)
+	defer tw.Close()
+
+	dockerFile := "Dockerfile"
+
+	// open docker file
+	f, err := os.Open(filepath.Join(s.Path, dockerFile))
+	if err != nil {
+		return nil, err
+	}
+	// read docker file
+	by, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+
+	tarHeader := &tar.Header{
+		Name: dockerFile,
+		Size: int64(len(by)),
+	}
+	err = tw.WriteHeader(tarHeader)
+	if err != nil {
+		return nil, err
+	}
+	_, err = tw.Write(by)
+	if err != nil {
+		return nil, err
+	}
+	tr := bytes.NewReader(buf.Bytes())
+
+	err = d.Client.BuildImage(docker.BuildImageOptions{
+		Name:           image,
+		Dockerfile:     dockerFile,
+		InputStream:    tr,
+		OutputStream:   ioutil.Discard,
+		RmTmpContainer: true,
+		SuppressOutput: true,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &build.Package{
+		Name:   image,
+		Path:   image,
+		Type:   "docker",
+		Source: s,
+	}, nil
+}
+
+func (d *dockerBuild) Remove(b *build.Package) error {
+	return d.Client.RemoveImage(b.Name)
+}
+
+func (d *dockerBuild) String() string {
+	return "docker"
+}
+
+func NewBuild(opts ...build.Option) build.Build {
+	options := build.Options{}
+	for _, o := range opts {
+		o(&options)
+	}
+	endpoint := "unix:///var/run/docker.sock"
+	client, err := docker.NewClient(endpoint)
+	if err != nil {
+		logger.Fatal(err)
+	}
+	return &dockerBuild{
+		Options: options,
+		Client:  client,
+	}
+}