driver: add docker driver

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

driver/docker/driver.go

@@ -0,0 +1,48 @@
+package docker
+
+import (
+	"context"
+	"net"
+	"time"
+
+	dockertypes "github.com/docker/docker/api/types"
+	"github.com/moby/buildkit/client"
+	"github.com/pkg/errors"
+	"github.com/tonistiigi/buildx/driver"
+	"github.com/tonistiigi/buildx/util/progress"
+)
+
+var buildkitImage = "moby/buildkit:master" // TODO: make this verified and configuratble
+
+type Driver struct {
+	driver.InitConfig
+	version dockertypes.Version
+}
+
+func (d *Driver) Bootstrap(ctx context.Context, l progress.Logger) error {
+	return nil
+}
+
+func (d *Driver) Info(ctx context.Context) (*driver.Info, error) {
+	_, err := d.DockerAPI.ServerVersion(ctx)
+	if err != nil {
+		return nil, errors.Wrapf(driver.ErrNotConnecting, err.Error())
+	}
+	return &driver.Info{
+		Status: driver.Running,
+	}, nil
+}
+
+func (d *Driver) Stop(ctx context.Context, force bool) error {
+	return nil
+}
+
+func (d *Driver) Rm(ctx context.Context, force bool) error {
+	return nil
+}
+
+func (d *Driver) Client(ctx context.Context) (*client.Client, error) {
+	return client.New(ctx, "", client.WithDialer(func(string, time.Duration) (net.Conn, error) {
+		return d.DockerAPI.DialHijack(ctx, "/grpc", "h2c", nil)
+	}))
+}