vendor: add buildkit

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/moby/buildkit/session/grpchijack/dial.go

@@ -0,0 +1,156 @@
+package grpchijack
+
+import (
+	"context"
+	"io"
+	"net"
+	"strings"
+	"sync"
+	"time"
+
+	controlapi "github.com/moby/buildkit/api/services/control"
+	"github.com/moby/buildkit/session"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+func Dialer(api controlapi.ControlClient) session.Dialer {
+	return func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error) {
+
+		meta = lowerHeaders(meta)
+
+		md := metadata.MD(meta)
+
+		ctx = metadata.NewOutgoingContext(ctx, md)
+
+		stream, err := api.Session(ctx)
+		if err != nil {
+			return nil, err
+		}
+
+		c, _ := streamToConn(stream)
+		return c, nil
+	}
+}
+
+func streamToConn(stream grpc.Stream) (net.Conn, <-chan struct{}) {
+	closeCh := make(chan struct{})
+	c := &conn{stream: stream, buf: make([]byte, 32*1<<10), closeCh: closeCh}
+	return c, closeCh
+}
+
+type conn struct {
+	stream  grpc.Stream
+	buf     []byte
+	lastBuf []byte
+
+	closedOnce sync.Once
+	readMu     sync.Mutex
+	err        error
+	closeCh    chan struct{}
+}
+
+func (c *conn) Read(b []byte) (n int, err error) {
+	c.readMu.Lock()
+	defer c.readMu.Unlock()
+
+	if c.lastBuf != nil {
+		n := copy(b, c.lastBuf)
+		c.lastBuf = c.lastBuf[n:]
+		if len(c.lastBuf) == 0 {
+			c.lastBuf = nil
+		}
+		return n, nil
+	}
+	m := new(controlapi.BytesMessage)
+	m.Data = c.buf
+
+	if err := c.stream.RecvMsg(m); err != nil {
+		return 0, err
+	}
+	c.buf = m.Data[:cap(m.Data)]
+
+	n = copy(b, m.Data)
+	if n < len(m.Data) {
+		c.lastBuf = m.Data[n:]
+	}
+
+	return n, nil
+}
+
+func (c *conn) Write(b []byte) (int, error) {
+	m := &controlapi.BytesMessage{Data: b}
+	if err := c.stream.SendMsg(m); err != nil {
+		return 0, err
+	}
+	return len(b), nil
+}
+
+func (c *conn) Close() (err error) {
+	c.closedOnce.Do(func() {
+		defer func() {
+			close(c.closeCh)
+		}()
+
+		if cs, ok := c.stream.(grpc.ClientStream); ok {
+			err = cs.CloseSend()
+			if err != nil {
+				return
+			}
+		}
+
+		c.readMu.Lock()
+		for {
+			m := new(controlapi.BytesMessage)
+			m.Data = c.buf
+			err = c.stream.RecvMsg(m)
+			if err != nil {
+				if err != io.EOF {
+					return
+				}
+				err = nil
+				break
+			}
+			c.buf = m.Data[:cap(m.Data)]
+			c.lastBuf = append(c.lastBuf, c.buf...)
+		}
+		c.readMu.Unlock()
+
+	})
+	return nil
+}
+
+func (c *conn) LocalAddr() net.Addr {
+	return dummyAddr{}
+}
+func (c *conn) RemoteAddr() net.Addr {
+	return dummyAddr{}
+}
+func (c *conn) SetDeadline(t time.Time) error {
+	return nil
+}
+func (c *conn) SetReadDeadline(t time.Time) error {
+	return nil
+}
+func (c *conn) SetWriteDeadline(t time.Time) error {
+	return nil
+}
+
+type dummyAddr struct {
+}
+
+func (d dummyAddr) Network() string {
+	return "tcp"
+}
+
+func (d dummyAddr) String() string {
+	return "localhost"
+}
+
+func lowerHeaders(in map[string][]string) map[string][]string {
+	out := map[string][]string{}
+	for k := range in {
+		out[strings.ToLower(k)] = in[k]
+	}
+	return out
+}

vendor/github.com/moby/buildkit/session/grpchijack/hijack.go

@@ -0,0 +1,15 @@
+package grpchijack
+
+import (
+	"net"
+
+	controlapi "github.com/moby/buildkit/api/services/control"
+	"google.golang.org/grpc/metadata"
+)
+
+// Hijack hijacks session to a connection.
+func Hijack(stream controlapi.Control_SessionServer) (net.Conn, <-chan struct{}, map[string][]string) {
+	md, _ := metadata.FromIncomingContext(stream.Context())
+	c, closeCh := streamToConn(stream)
+	return c, closeCh, md
+}