Merge pull request #27 from tiborvass/docker-ui

build: add more docker UI (context/dockerfile handling, iidfile, add-host, network)

build/build.go

@@ -1,16 +1,22 @@
 package build
 
 import (
+	"bufio"
 	"context"
 	"io"
+	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
 	"sync"
 
 	"github.com/containerd/containerd/platforms"
+	"github.com/docker/distribution/reference"
+	"github.com/docker/docker/pkg/urlutil"
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/session/upload/uploadprovider"
 	specs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"github.com/tonistiigi/buildx/driver"
@@ -18,12 +24,20 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
+var (
+	errStdinConflict      = errors.New("invalid argument: can't use stdin for both build context and dockerfile")
+	errDockerfileConflict = errors.New("ambiguous Dockerfile source: both stdin and flag correspond to Dockerfiles")
+)
+
 type Options struct {
 	Inputs      Inputs
 	Tags        []string
 	Labels      map[string]string
 	BuildArgs   map[string]string
 	Pull        bool
+	ImageIDFile string
+	ExtraHosts  []string
+	NetworkMode string
 
 	NoCache   bool
 	Target    string
@@ -96,9 +110,20 @@ func Build(ctx context.Context, drivers []DriverInfo, opt map[string]Options, pw
 	for k, opt := range opt {
 		pw := mw.WithPrefix(k, withPrefix)
 
+		if opt.ImageIDFile != "" {
+			if len(opt.Platforms) != 0 {
+				return nil, errors.Errorf("image ID file cannot be specified when building for multiple platforms")
+			}
+			// Avoid leaving a stale file if we eventually fail
+			if err := os.Remove(opt.ImageIDFile); err != nil && !os.IsNotExist(err) {
+				return nil, errors.Wrap(err, "removing image ID file")
+			}
+		}
+
 		so := client.SolveOpt{
 			Frontend:      "dockerfile.v0",
 			FrontendAttrs: map[string]string{},
+			LocalDirs:     map[string]string{},
 		}
 
 		switch len(opt.Exports) {
@@ -115,10 +140,18 @@ func Build(ctx context.Context, drivers []DriverInfo, opt map[string]Options, pw
 		}
 
 		if len(opt.Tags) > 0 {
+			tags := make([]string, len(opt.Tags))
+			for i, tag := range opt.Tags {
+				ref, err := reference.Parse(tag)
+				if err != nil {
+					return nil, errors.Wrapf(err, "invalid tag %q", tag)
+				}
+				tags[i] = ref.String()
+			}
 			for i, e := range opt.Exports {
 				switch e.Type {
 				case "image", "oci", "docker":
-					opt.Exports[i].Attrs["name"] = strings.Join(opt.Tags, ",")
+					opt.Exports[i].Attrs["name"] = strings.Join(tags, ",")
 				}
 			}
 		} else {
@@ -132,6 +165,9 @@ func Build(ctx context.Context, drivers []DriverInfo, opt map[string]Options, pw
 		}
 
 		for i, e := range opt.Exports {
+			if (e.Type == "local" || e.Type == "tar") && opt.ImageIDFile != "" {
+				return nil, errors.Errorf("local and tar exporters are incompatible with image ID file")
+			}
 			if e.Type == "oci" && !d.Features()[driver.OCIExporter] {
 				return nil, notSupported(d, driver.OCIExporter)
 			}
@@ -160,9 +196,11 @@ func Build(ctx context.Context, drivers []DriverInfo, opt map[string]Options, pw
 		so.Exports = opt.Exports
 		so.Session = opt.Session
 
-		if err := LoadInputs(opt.Inputs, &so); err != nil {
+		release, err := LoadInputs(opt.Inputs, &so)
+		if err != nil {
 			return nil, err
 		}
+		defer release()
 
 		if opt.Pull {
 			so.FrontendAttrs["image-resolve-mode"] = "pull"
@@ -191,6 +229,20 @@ func Build(ctx context.Context, drivers []DriverInfo, opt map[string]Options, pw
 			so.FrontendAttrs["platform"] = strings.Join(pp, ",")
 		}
 
+		switch opt.NetworkMode {
+		case "host", "none":
+			so.FrontendAttrs["force-network-mode"] = opt.NetworkMode
+		case "", "default":
+		default:
+			return nil, errors.Errorf("network mode %q not supported by buildkit", opt.NetworkMode)
+		}
+
+		extraHosts, err := toBuildkitExtraHosts(opt.ExtraHosts)
+		if err != nil {
+			return nil, err
+		}
+		so.FrontendAttrs["add-hosts"] = extraHosts
+
 		var statusCh chan *client.SolveStatus
 		if pw != nil {
 			statusCh = pw.Status()
@@ -208,6 +260,9 @@ func Build(ctx context.Context, drivers []DriverInfo, opt map[string]Options, pw
 			mu.Lock()
 			resp[k] = rr
 			mu.Unlock()
+			if opt.ImageIDFile != "" {
+				return ioutil.WriteFile(opt.ImageIDFile, []byte(rr.ExporterResponse["containerimage.digest"]), 0644)
+			}
 			return nil
 		})
 	}
@@ -219,30 +274,109 @@ func Build(ctx context.Context, drivers []DriverInfo, opt map[string]Options, pw
 	return resp, nil
 }
 
-func LoadInputs(inp Inputs, target *client.SolveOpt) error {
+func createTempDockerfile(r io.Reader) (string, error) {
+	dir, err := ioutil.TempDir("", "dockerfile")
+	if err != nil {
+		return "", err
+	}
+	f, err := os.Create(filepath.Join(dir, "Dockerfile"))
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	if _, err := io.Copy(f, r); err != nil {
+		return "", err
+	}
+	return dir, err
+}
+
+func LoadInputs(inp Inputs, target *client.SolveOpt) (func(), error) {
 	if inp.ContextPath == "" {
-		return errors.New("please specify build context (e.g. \".\" for the current directory)")
+		return nil, errors.New("please specify build context (e.g. \".\" for the current directory)")
 	}
 
 	// TODO: handle stdin, symlinks, remote contexts, check files exist
 
-	if inp.DockerfilePath == "" {
+	var (
-		inp.DockerfilePath = filepath.Join(inp.ContextPath, "Dockerfile")
+		err              error
+		dockerfileReader io.Reader
+		dockerfileDir    string
+		dockerfileName   = inp.DockerfilePath
+		toRemove         []string
+	)
+
+	switch {
+	case inp.ContextPath == "-":
+		if inp.DockerfilePath == "-" {
+			return nil, errStdinConflict
 		}
 
-	if target.LocalDirs == nil {
+		buf := bufio.NewReader(os.Stdin)
-		target.LocalDirs = map[string]string{}
+		magic, err := buf.Peek(archiveHeaderSize * 2)
+		if err != nil && err != io.EOF {
+			return nil, errors.Wrap(err, "failed to peek context header from STDIN")
 		}
 
+		if isArchive(magic) {
+			// stdin is context
+			up := uploadprovider.New()
+			target.FrontendAttrs["context"] = up.Add(buf)
+			target.Session = append(target.Session, up)
+		} else {
+			if inp.DockerfilePath != "" {
+				return nil, errDockerfileConflict
+			}
+			// stdin is dockerfile
+			dockerfileReader = buf
+			inp.ContextPath, _ = ioutil.TempDir("", "empty-dir")
+			toRemove = append(toRemove, inp.ContextPath)
 			target.LocalDirs["context"] = inp.ContextPath
-	target.LocalDirs["dockerfile"] = filepath.Dir(inp.DockerfilePath)
-
-	if target.FrontendAttrs == nil {
-		target.FrontendAttrs = map[string]string{}
 		}
 
-	target.FrontendAttrs["filename"] = filepath.Base(inp.DockerfilePath)
+	case isLocalDir(inp.ContextPath):
-	return nil
+		target.LocalDirs["context"] = inp.ContextPath
+		switch inp.DockerfilePath {
+		case "-":
+			dockerfileReader = os.Stdin
+		case "":
+			dockerfileDir = inp.ContextPath
+		default:
+			dockerfileDir = filepath.Dir(inp.DockerfilePath)
+			dockerfileName = filepath.Base(inp.DockerfilePath)
+		}
+
+	case urlutil.IsGitURL(inp.ContextPath), urlutil.IsURL(inp.ContextPath):
+		if inp.DockerfilePath == "-" {
+			return nil, errors.Errorf("Dockerfile from stdin is not supported with remote contexts")
+		}
+		target.FrontendAttrs["context"] = inp.ContextPath
+	default:
+		return nil, errors.Errorf("unable to prepare context: path %q not found", inp.ContextPath)
+	}
+
+	if dockerfileReader != nil {
+		dockerfileDir, err = createTempDockerfile(dockerfileReader)
+		if err != nil {
+			return nil, err
+		}
+		toRemove = append(toRemove, dockerfileDir)
+	}
+
+	if dockerfileName == "" {
+		dockerfileName = "Dockerfile"
+	}
+	target.FrontendAttrs["filename"] = dockerfileName
+
+	if dockerfileDir != "" {
+		target.LocalDirs["dockerfile"] = dockerfileDir
+	}
+
+	release := func() {
+		for _, dir := range toRemove {
+			os.RemoveAll(dir)
+		}
+	}
+	return release, nil
 }
 
 func notSupported(d driver.Driver, f driver.Feature) error {

build/output.go

@@ -37,7 +37,7 @@ func ParseOutputs(inp []string) ([]client.ExportEntry, error) {
 			if len(parts) != 2 {
 				return nil, errors.Errorf("invalid value %s", field)
 			}
-			key := strings.ToLower(parts[0])
+			key := strings.TrimSpace(strings.ToLower(parts[0]))
 			value := parts[1]
 			switch key {
 			case "type":

build/utils.go

@@ -0,0 +1,55 @@
+package build
+
+import (
+	"archive/tar"
+	"bytes"
+	"net"
+	"os"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+// archiveHeaderSize is the number of bytes in an archive header
+const archiveHeaderSize = 512
+
+func isLocalDir(c string) bool {
+	st, err := os.Stat(c)
+	return err == nil && st.IsDir()
+}
+
+func isArchive(header []byte) bool {
+	for _, m := range [][]byte{
+		{0x42, 0x5A, 0x68},                   // bzip2
+		{0x1F, 0x8B, 0x08},                   // gzip
+		{0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00}, // xz
+	} {
+		if len(header) < len(m) {
+			continue
+		}
+		if bytes.Equal(m, header[:len(m)]) {
+			return true
+		}
+	}
+
+	r := tar.NewReader(bytes.NewBuffer(header))
+	_, err := r.Next()
+	return err == nil
+}
+
+// toBuildkitExtraHosts converts hosts from docker key:value format to buildkit's csv format
+func toBuildkitExtraHosts(inp []string) (string, error) {
+	if len(inp) == 0 {
+		return "", nil
+	}
+	hosts := make([]string, 0, len(inp))
+	for _, h := range inp {
+		parts := strings.Split(h, ":")
+
+		if len(parts) != 2 || parts[0] == "" || net.ParseIP(parts[1]) == nil {
+			return "", errors.Errorf("invalid host %s", h)
+		}
+		hosts = append(hosts, parts[0]+"="+parts[1])
+	}
+	return strings.Join(hosts, ","), nil
+}

commands/build.go

@@ -30,13 +30,13 @@ type buildOptions struct {
 	secrets     []string
 	ssh         []string
 	outputs     []string
+	imageIDFile string
+	extraHosts  []string
+	networkMode string
 
 	// unimplemented
-	extraHosts  []string
 	squash bool
 	quiet  bool
-	networkMode string
-	imageIDFile string
 
 	// hidden
 	// untrusted   bool
@@ -62,21 +62,12 @@ type commonOptions struct {
 }
 
 func runBuild(dockerCli command.Cli, in buildOptions) error {
-	if len(in.extraHosts) > 0 {
-		return errors.Errorf("extra hosts currently not implemented")
-	}
 	if in.squash {
 		return errors.Errorf("squash currently not implemented")
 	}
 	if in.quiet {
 		return errors.Errorf("quiet currently not implemented")
 	}
-	if in.networkMode != "default" {
-		return errors.Errorf("network currently not implemented")
-	}
-	if in.imageIDFile != "" {
-		return errors.Errorf("iidfile currently not implemented")
-	}
 
 	ctx := appcontext.Context()
 
@@ -92,6 +83,9 @@ func runBuild(dockerCli command.Cli, in buildOptions) error {
 		Pull:        in.pull,
 		NoCache:     in.noCache,
 		Target:      in.target,
+		ImageIDFile: in.imageIDFile,
+		ExtraHosts:  in.extraHosts,
+		NetworkMode: in.networkMode,
 	}
 
 	platforms, err := build.ParsePlatformSpecs(in.platforms)
@@ -170,9 +164,6 @@ func buildCmd(dockerCli command.Cli) *cobra.Command {
 	flags.StringVar(&options.imageIDFile, "iidfile", "", "Write the image ID to the file")
 	flags.BoolVar(&options.squash, "squash", false, "Squash newly built layers into a single new layer")
 	flags.MarkHidden("quiet")
-	flags.MarkHidden("network")
-	flags.MarkHidden("add-host")
-	flags.MarkHidden("iidfile")
 	flags.MarkHidden("squash")
 
 	// hidden flags

go.mod

@@ -57,7 +57,7 @@ require (
 	github.com/mattn/go-sqlite3 v1.10.0 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/miekg/pkcs11 v0.0.0-20190322140431-074fd7a1ed19 // indirect
-	github.com/moby/buildkit v0.4.1-0.20190410165125-b4a6a0e3a7d1
+	github.com/moby/buildkit v0.4.1-0.20190410165125-bcd466a748e950507826c30e835b087289aaf384
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.1 // indirect
 	github.com/opencontainers/go-digest v1.0.0-rc1

go.sum

@@ -88,6 +88,7 @@ github.com/docker/go-metrics v0.0.0-20170502235133-d466d4f6fd96 h1:HVQ/BC7Ze+bcV
 github.com/docker/go-metrics v0.0.0-20170502235133-d466d4f6fd96/go.mod h1:/u0gXw0Gay3ceNrsHubL3BtdOL2fHf93USgMTe0W5dI=
 github.com/docker/go-units v0.3.1 h1:QAFdsA6jLCnglbqE6mUsHuPcJlntY94DkxHf4deHKIU=
 github.com/docker/go-units v0.3.1/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
+github.com/docker/libnetwork v0.0.0-20180913200009-36d3bed0e9f4 h1:PmuO8T1R9jxvOI+Y6+8YBF+um2L6xp6/F52oDeYTZkk=
 github.com/docker/libnetwork v0.0.0-20180913200009-36d3bed0e9f4/go.mod h1:93m0aTqz6z+g32wla4l4WxTrdtvBRmVzYRkYvasA5Z8=
 github.com/docker/libtrust v0.0.0-20150526203908-9cbd2a1374f4 h1:k8TfKGeAcDQFFQOGCQMRN04N4a9YrPlRMMKnzAuvM9Q=
 github.com/docker/libtrust v0.0.0-20150526203908-9cbd2a1374f4/go.mod h1:cyGadeNEkKy96OOhEzfZl+yxihPEzKnqJwvfuSUqbZE=
@@ -187,8 +188,8 @@ github.com/miekg/pkcs11 v0.0.0-20190322140431-074fd7a1ed19/go.mod h1:WCBAbTOdfhH
 github.com/mitchellh/hashstructure v0.0.0-20170609045927-2bca23e0e452/go.mod h1:QjSHrPWS+BGUVBYkbTZWEnOh3G1DutKwClXU/ABz6AQ=
 github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
-github.com/moby/buildkit v0.4.1-0.20190410165125-b4a6a0e3a7d1 h1:e8eXboh2H1zYsGDo/nPuZQReAd2eGEtQV1AFX9BncWo=
+github.com/moby/buildkit v0.4.1-0.20190410165125-bcd466a748e950507826c30e835b087289aaf384 h1:SsOa4L1rQyJlSUm7fBAspkBNHDgmcUU60WOZPGuTTy4=
-github.com/moby/buildkit v0.4.1-0.20190410165125-b4a6a0e3a7d1/go.mod h1:ivyIn0/bTW+YAXWeOqMWJ9aHLeac6SKIB4QeGlxzu/Q=
+github.com/moby/buildkit v0.4.1-0.20190410165125-bcd466a748e950507826c30e835b087289aaf384/go.mod h1:ivyIn0/bTW+YAXWeOqMWJ9aHLeac6SKIB4QeGlxzu/Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.1 h1:9f412s+6RmYXLWZSEzVVgPGK7C2PphHj5RJrvfx9AWI=
@@ -265,7 +266,9 @@ github.com/uber/jaeger-client-go v0.0.0-20180103221425-e02c85f9069e/go.mod h1:WV
 github.com/uber/jaeger-lib v1.2.1/go.mod h1:ComeNDZlWwrWnDv8aPp0Ba6+uUTzImX/AauajbLI56U=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/urfave/cli v0.0.0-20171014202726-7bc6a0acffa5/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
+github.com/vishvananda/netlink v1.0.0 h1:bqNY2lgheFIu1meHUFSH3d7vG93AFyqg3oGbJCOJgSM=
 github.com/vishvananda/netlink v1.0.0/go.mod h1:+SR5DhBJrl6ZM7CoCKvpw5BKroDKQ+PJqOg65H/2ktk=
+github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc h1:R83G5ikgLMxrBvLh22JhdfI8K6YXEPHx5P03Uu3DRs4=
 github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc/go.mod h1:ZjcWmFBXmLKZu9Nxj3WKYEafiSqer2rnvPr0en9UNpI=
 github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f h1:J9EGpcZtP0E/raorCMxlFGSTBrsSlaDGf3jU/qvAE2c=
 github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f/go.mod h1:N2zxlSyiKSe5eX1tZViRH5QA0qijqEDrYZiPEAiq3wU=

vendor/github.com/docker/docker/pkg/urlutil/urlutil.go

@@ -0,0 +1,52 @@
+// Package urlutil provides helper function to check urls kind.
+// It supports http urls, git urls and transport url (tcp://, …)
+package urlutil // import "github.com/docker/docker/pkg/urlutil"
+
+import (
+	"regexp"
+	"strings"
+)
+
+var (
+	validPrefixes = map[string][]string{
+		"url": {"http://", "https://"},
+
+		// The github.com/ prefix is a special case used to treat context-paths
+		// starting with `github.com` as a git URL if the given path does not
+		// exist locally. The "github.com/" prefix is kept for backward compatibility,
+		// and is a legacy feature.
+		//
+		// Going forward, no additional prefixes should be added, and users should
+		// be encouraged to use explicit URLs (https://github.com/user/repo.git) instead.
+		"git":       {"git://", "github.com/", "git@"},
+		"transport": {"tcp://", "tcp+tls://", "udp://", "unix://", "unixgram://"},
+	}
+	urlPathWithFragmentSuffix = regexp.MustCompile(".git(?:#.+)?$")
+)
+
+// IsURL returns true if the provided str is an HTTP(S) URL.
+func IsURL(str string) bool {
+	return checkURL(str, "url")
+}
+
+// IsGitURL returns true if the provided str is a git repository URL.
+func IsGitURL(str string) bool {
+	if IsURL(str) && urlPathWithFragmentSuffix.MatchString(str) {
+		return true
+	}
+	return checkURL(str, "git")
+}
+
+// IsTransportURL returns true if the provided str is a transport (tcp, tcp+tls, udp, unix) URL.
+func IsTransportURL(str string) bool {
+	return checkURL(str, "transport")
+}
+
+func checkURL(str, kind string) bool {
+	for _, prefix := range validPrefixes[kind] {
+		if strings.HasPrefix(str, prefix) {
+			return true
+		}
+	}
+	return false
+}

vendor/github.com/moby/buildkit/session/upload/generate.go

@@ -0,0 +1,3 @@
+package upload
+
+//go:generate protoc --gogoslick_out=plugins=grpc:. upload.proto

vendor/github.com/moby/buildkit/session/upload/upload.go

@@ -0,0 +1,55 @@
+package upload
+
+import (
+	"context"
+	io "io"
+	"net/url"
+
+	"github.com/moby/buildkit/session"
+	"google.golang.org/grpc/metadata"
+)
+
+const (
+	keyPath = "urlpath"
+	keyHost = "urlhost"
+)
+
+func New(ctx context.Context, c session.Caller, url *url.URL) (*Upload, error) {
+	opts := map[string][]string{
+		keyPath: {url.Path},
+		keyHost: {url.Host},
+	}
+
+	client := NewUploadClient(c.Conn())
+
+	ctx = metadata.NewOutgoingContext(ctx, opts)
+
+	cc, err := client.Pull(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Upload{cc: cc}, nil
+}
+
+type Upload struct {
+	cc Upload_PullClient
+}
+
+func (u *Upload) WriteTo(w io.Writer) (int, error) {
+	n := 0
+	for {
+		var bm BytesMessage
+		if err := u.cc.RecvMsg(&bm); err != nil {
+			if err == io.EOF {
+				return n, nil
+			}
+			return n, err
+		}
+		nn, err := w.Write(bm.Data)
+		n += nn
+		if err != nil {
+			return n, err
+		}
+	}
+}

vendor/github.com/moby/buildkit/session/upload/upload.pb.go

@@ -0,0 +1,506 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: upload.proto
+
+package upload
+
+import proto "github.com/gogo/protobuf/proto"
+import fmt "fmt"
+import math "math"
+
+import bytes "bytes"
+
+import strings "strings"
+import reflect "reflect"
+
+import (
+	context "golang.org/x/net/context"
+	grpc "google.golang.org/grpc"
+)
+
+import io "io"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.GoGoProtoPackageIsVersion2 // please upgrade the proto package
+
+// BytesMessage contains a chunk of byte data
+type BytesMessage struct {
+	Data []byte `protobuf:"bytes,1,opt,name=data,proto3" json:"data,omitempty"`
+}
+
+func (m *BytesMessage) Reset()      { *m = BytesMessage{} }
+func (*BytesMessage) ProtoMessage() {}
+func (*BytesMessage) Descriptor() ([]byte, []int) {
+	return fileDescriptor_upload_0898dc79ebc86e9c, []int{0}
+}
+func (m *BytesMessage) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *BytesMessage) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_BytesMessage.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalTo(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (dst *BytesMessage) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_BytesMessage.Merge(dst, src)
+}
+func (m *BytesMessage) XXX_Size() int {
+	return m.Size()
+}
+func (m *BytesMessage) XXX_DiscardUnknown() {
+	xxx_messageInfo_BytesMessage.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_BytesMessage proto.InternalMessageInfo
+
+func (m *BytesMessage) GetData() []byte {
+	if m != nil {
+		return m.Data
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*BytesMessage)(nil), "moby.upload.v1.BytesMessage")
+}
+func (this *BytesMessage) Equal(that interface{}) bool {
+	if that == nil {
+		return this == nil
+	}
+
+	that1, ok := that.(*BytesMessage)
+	if !ok {
+		that2, ok := that.(BytesMessage)
+		if ok {
+			that1 = &that2
+		} else {
+			return false
+		}
+	}
+	if that1 == nil {
+		return this == nil
+	} else if this == nil {
+		return false
+	}
+	if !bytes.Equal(this.Data, that1.Data) {
+		return false
+	}
+	return true
+}
+func (this *BytesMessage) GoString() string {
+	if this == nil {
+		return "nil"
+	}
+	s := make([]string, 0, 5)
+	s = append(s, "&upload.BytesMessage{")
+	s = append(s, "Data: "+fmt.Sprintf("%#v", this.Data)+",\n")
+	s = append(s, "}")
+	return strings.Join(s, "")
+}
+func valueToGoStringUpload(v interface{}, typ string) string {
+	rv := reflect.ValueOf(v)
+	if rv.IsNil() {
+		return "nil"
+	}
+	pv := reflect.Indirect(rv).Interface()
+	return fmt.Sprintf("func(v %v) *%v { return &v } ( %#v )", typ, typ, pv)
+}
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ context.Context
+var _ grpc.ClientConn
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+const _ = grpc.SupportPackageIsVersion4
+
+// UploadClient is the client API for Upload service.
+//
+// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
+type UploadClient interface {
+	Pull(ctx context.Context, opts ...grpc.CallOption) (Upload_PullClient, error)
+}
+
+type uploadClient struct {
+	cc *grpc.ClientConn
+}
+
+func NewUploadClient(cc *grpc.ClientConn) UploadClient {
+	return &uploadClient{cc}
+}
+
+func (c *uploadClient) Pull(ctx context.Context, opts ...grpc.CallOption) (Upload_PullClient, error) {
+	stream, err := c.cc.NewStream(ctx, &_Upload_serviceDesc.Streams[0], "/moby.upload.v1.Upload/Pull", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &uploadPullClient{stream}
+	return x, nil
+}
+
+type Upload_PullClient interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ClientStream
+}
+
+type uploadPullClient struct {
+	grpc.ClientStream
+}
+
+func (x *uploadPullClient) Send(m *BytesMessage) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *uploadPullClient) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+// UploadServer is the server API for Upload service.
+type UploadServer interface {
+	Pull(Upload_PullServer) error
+}
+
+func RegisterUploadServer(s *grpc.Server, srv UploadServer) {
+	s.RegisterService(&_Upload_serviceDesc, srv)
+}
+
+func _Upload_Pull_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(UploadServer).Pull(&uploadPullServer{stream})
+}
+
+type Upload_PullServer interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ServerStream
+}
+
+type uploadPullServer struct {
+	grpc.ServerStream
+}
+
+func (x *uploadPullServer) Send(m *BytesMessage) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *uploadPullServer) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+var _Upload_serviceDesc = grpc.ServiceDesc{
+	ServiceName: "moby.upload.v1.Upload",
+	HandlerType: (*UploadServer)(nil),
+	Methods:     []grpc.MethodDesc{},
+	Streams: []grpc.StreamDesc{
+		{
+			StreamName:    "Pull",
+			Handler:       _Upload_Pull_Handler,
+			ServerStreams: true,
+			ClientStreams: true,
+		},
+	},
+	Metadata: "upload.proto",
+}
+
+func (m *BytesMessage) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *BytesMessage) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Data) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintUpload(dAtA, i, uint64(len(m.Data)))
+		i += copy(dAtA[i:], m.Data)
+	}
+	return i, nil
+}
+
+func encodeVarintUpload(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *BytesMessage) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.Data)
+	if l > 0 {
+		n += 1 + l + sovUpload(uint64(l))
+	}
+	return n
+}
+
+func sovUpload(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozUpload(x uint64) (n int) {
+	return sovUpload(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (this *BytesMessage) String() string {
+	if this == nil {
+		return "nil"
+	}
+	s := strings.Join([]string{`&BytesMessage{`,
+		`Data:` + fmt.Sprintf("%v", this.Data) + `,`,
+		`}`,
+	}, "")
+	return s
+}
+func valueToStringUpload(v interface{}) string {
+	rv := reflect.ValueOf(v)
+	if rv.IsNil() {
+		return "nil"
+	}
+	pv := reflect.Indirect(rv).Interface()
+	return fmt.Sprintf("*%v", pv)
+}
+func (m *BytesMessage) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowUpload
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: BytesMessage: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: BytesMessage: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Data", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowUpload
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthUpload
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Data = append(m.Data[:0], dAtA[iNdEx:postIndex]...)
+			if m.Data == nil {
+				m.Data = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipUpload(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthUpload
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipUpload(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowUpload
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowUpload
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowUpload
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthUpload
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowUpload
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipUpload(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthUpload = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowUpload   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("upload.proto", fileDescriptor_upload_0898dc79ebc86e9c) }
+
+var fileDescriptor_upload_0898dc79ebc86e9c = []byte{
+	// 179 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x29, 0x2d, 0xc8, 0xc9,
+	0x4f, 0x4c, 0xd1, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0xe2, 0xcb, 0xcd, 0x4f, 0xaa, 0xd4, 0x83,
+	0x0a, 0x95, 0x19, 0x2a, 0x29, 0x71, 0xf1, 0x38, 0x55, 0x96, 0xa4, 0x16, 0xfb, 0xa6, 0x16, 0x17,
+	0x27, 0xa6, 0xa7, 0x0a, 0x09, 0x71, 0xb1, 0xa4, 0x24, 0x96, 0x24, 0x4a, 0x30, 0x2a, 0x30, 0x6a,
+	0xf0, 0x04, 0x81, 0xd9, 0x46, 0x01, 0x5c, 0x6c, 0xa1, 0x60, 0x0d, 0x42, 0x6e, 0x5c, 0x2c, 0x01,
+	0xa5, 0x39, 0x39, 0x42, 0x32, 0x7a, 0xa8, 0xc6, 0xe8, 0x21, 0x9b, 0x21, 0x85, 0x57, 0x56, 0x83,
+	0xd1, 0x80, 0xd1, 0xc9, 0xe6, 0xc2, 0x43, 0x39, 0x86, 0x1b, 0x0f, 0xe5, 0x18, 0x3e, 0x3c, 0x94,
+	0x63, 0x6c, 0x78, 0x24, 0xc7, 0xb8, 0xe2, 0x91, 0x1c, 0xe3, 0x89, 0x47, 0x72, 0x8c, 0x17, 0x1e,
+	0xc9, 0x31, 0x3e, 0x78, 0x24, 0xc7, 0xf8, 0xe2, 0x91, 0x1c, 0xc3, 0x87, 0x47, 0x72, 0x8c, 0x13,
+	0x1e, 0xcb, 0x31, 0x5c, 0x78, 0x2c, 0xc7, 0x70, 0xe3, 0xb1, 0x1c, 0x43, 0x14, 0x1b, 0xc4, 0xc4,
+	0x24, 0x36, 0xb0, 0x57, 0x8c, 0x01, 0x01, 0x00, 0x00, 0xff, 0xff, 0x12, 0xf2, 0xfc, 0xb4, 0xda,
+	0x00, 0x00, 0x00,
+}

vendor/github.com/moby/buildkit/session/upload/upload.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+package moby.upload.v1;
+
+option go_package = "upload";
+
+service Upload {
+	rpc Pull(stream BytesMessage) returns (stream BytesMessage);
+}
+
+// BytesMessage contains a chunk of byte data
+message BytesMessage{
+	bytes data = 1;
+}

vendor/github.com/moby/buildkit/session/upload/uploadprovider/provider.go

@@ -0,0 +1,66 @@
+package uploadprovider
+
+import (
+	"io"
+	"path"
+	"sync"
+
+	"github.com/moby/buildkit/identity"
+	"github.com/moby/buildkit/session/upload"
+	"github.com/pkg/errors"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+func New() *Uploader {
+	return &Uploader{m: map[string]io.Reader{}}
+}
+
+type Uploader struct {
+	mu sync.Mutex
+	m  map[string]io.Reader
+}
+
+func (hp *Uploader) Add(r io.Reader) string {
+	id := identity.NewID()
+	hp.m[id] = r
+	return "http://buildkit-session/" + id
+}
+
+func (hp *Uploader) Register(server *grpc.Server) {
+	upload.RegisterUploadServer(server, hp)
+}
+
+func (hp *Uploader) Pull(stream upload.Upload_PullServer) error {
+	opts, _ := metadata.FromIncomingContext(stream.Context()) // if no metadata continue with empty object
+	var p string
+	urls, ok := opts["urlpath"]
+	if ok && len(urls) > 0 {
+		p = urls[0]
+	}
+
+	p = path.Base(p)
+
+	hp.mu.Lock()
+	r, ok := hp.m[p]
+	if !ok {
+		hp.mu.Unlock()
+		return errors.Errorf("no http response from session for %s", p)
+	}
+	delete(hp.m, p)
+	hp.mu.Unlock()
+
+	_, err := io.Copy(&writer{stream}, r)
+	return err
+}
+
+type writer struct {
+	grpc.ServerStream
+}
+
+func (w *writer) Write(dt []byte) (int, error) {
+	if err := w.SendMsg(&upload.BytesMessage{Data: dt}); err != nil {
+		return 0, err
+	}
+	return len(dt), nil
+}

vendor/modules.txt

@@ -154,6 +154,7 @@ github.com/docker/distribution/registry/storage/cache/memory
 github.com/docker/distribution/uuid
 github.com/docker/distribution/metrics
 # github.com/docker/docker v1.14.0-0.20190410063227-d9d9eccdc862
+github.com/docker/docker/pkg/urlutil
 github.com/docker/docker/client
 github.com/docker/docker/api/types
 github.com/docker/docker/api/types/container
@@ -270,12 +271,13 @@ github.com/matttproud/golang_protobuf_extensions/pbutil
 github.com/miekg/pkcs11
 # github.com/mitchellh/mapstructure v1.1.2
 github.com/mitchellh/mapstructure
-# github.com/moby/buildkit v0.4.1-0.20190410165125-b4a6a0e3a7d1
+# github.com/moby/buildkit v0.4.1-0.20190410165125-bcd466a748e950507826c30e835b087289aaf384
 github.com/moby/buildkit/session/auth/authprovider
 github.com/moby/buildkit/client
 github.com/moby/buildkit/session
 github.com/moby/buildkit/session/secrets/secretsprovider
 github.com/moby/buildkit/session/sshforward/sshprovider
+github.com/moby/buildkit/session/upload/uploadprovider
 github.com/moby/buildkit/util/appcontext
 github.com/moby/buildkit/identity
 github.com/moby/buildkit/util/progress/progressui
@@ -298,6 +300,7 @@ github.com/moby/buildkit/util/appdefaults
 github.com/moby/buildkit/util/entitlements
 github.com/moby/buildkit/session/secrets
 github.com/moby/buildkit/session/sshforward
+github.com/moby/buildkit/session/upload
 github.com/moby/buildkit/util/system
 github.com/moby/buildkit/util/apicaps/pb
 # github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd