driver: add docker driver

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

cmd/buildx/main.go

@@ -8,6 +8,7 @@ import (
 	"github.com/tonistiigi/buildx/commands"
 	"github.com/tonistiigi/buildx/version"
 
+	_ "github.com/tonistiigi/buildx/driver/docker"
 	_ "github.com/tonistiigi/buildx/driver/docker-container"
 )
 

driver/docker-container/factory.go

@@ -7,6 +7,9 @@ import (
 	"github.com/tonistiigi/buildx/driver"
 )
 
+const prioritySupported = 30
+const priorityUnsupported = 70
+
 func init() {
 	driver.Register(&factory{})
 }
@@ -22,13 +25,16 @@ func (*factory) Usage() string {
 	return "docker-container"
 }
 
-func (*factory) Priority() int {
-	return 30
+func (*factory) Priority(cfg driver.InitConfig) int {
+	if cfg.DockerAPI == nil {
+		return priorityUnsupported
+	}
+	return prioritySupported
 }
 
-func (*factory) New(ctx context.Context, cfg driver.InitConfig) (driver.Driver, error) {
+func (f *factory) New(ctx context.Context, cfg driver.InitConfig) (driver.Driver, error) {
 	if cfg.DockerAPI == nil {
-		return nil, errors.Errorf("docker driver requires docker API access")
+		return nil, errors.Errorf("%s driver requires docker API access", f.Name())
 	}
 
 	v, err := cfg.DockerAPI.ServerVersion(ctx)

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)
+	}))
+}

driver/docker/factory.go

@@ -0,0 +1,53 @@
+package docker
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"github.com/tonistiigi/buildx/driver"
+)
+
+const prioritySupported = 10
+const priorityUnsupported = 99
+
+func init() {
+	driver.Register(&factory{})
+}
+
+type factory struct {
+}
+
+func (*factory) Name() string {
+	return "docker"
+}
+
+func (*factory) Usage() string {
+	return "docker"
+}
+
+func (*factory) Priority(cfg driver.InitConfig) int {
+	if cfg.DockerAPI == nil {
+		return priorityUnsupported
+	}
+
+	c, err := cfg.DockerAPI.DialHijack(context.TODO(), "/grpc", "h2c", nil)
+	if err != nil {
+		return priorityUnsupported
+	}
+	c.Close()
+
+	return prioritySupported
+}
+
+func (*factory) New(ctx context.Context, cfg driver.InitConfig) (driver.Driver, error) {
+	if cfg.DockerAPI == nil {
+		return nil, errors.Errorf("docker driver requires docker API access")
+	}
+
+	v, err := cfg.DockerAPI.ServerVersion(ctx)
+	if err != nil {
+		return nil, errors.Wrapf(driver.ErrNotConnecting, err.Error())
+	}
+
+	return &Driver{InitConfig: cfg, version: v}, nil
+}

driver/manager.go

@@ -11,7 +11,7 @@ import (
 type Factory interface {
 	Name() string
 	Usage() string
-	Priority() int // take initConfig?
+	Priority(cfg InitConfig) int
 	New(ctx context.Context, cfg InitConfig) (Driver, error)
 }
 
@@ -37,7 +37,7 @@ func Register(f Factory) {
 	drivers[f.Name()] = f
 }
 
-func GetDefaultFactory() (Factory, error) {
+func GetDefaultFactory(ic InitConfig) (Factory, error) {
 	if len(drivers) == 0 {
 		return nil, errors.Errorf("no drivers available")
 	}
@@ -47,7 +47,7 @@ func GetDefaultFactory() (Factory, error) {
 	}
 	dd := make([]p, 0, len(drivers))
 	for _, f := range drivers {
-		dd = append(dd, p{f: f, priority: f.Priority()})
+		dd = append(dd, p{f: f, priority: f.Priority(ic)})
 	}
 	sort.Slice(dd, func(i, j int) bool {
 		return dd[i].priority < dd[j].priority
@@ -56,15 +56,16 @@ func GetDefaultFactory() (Factory, error) {
 }
 
 func GetDriver(ctx context.Context, name string, f Factory, api dockerclient.APIClient) (Driver, error) {
+	ic := InitConfig{
+		DockerAPI: api,
+		Name:      name,
+	}
 	if f == nil {
 		var err error
-		f, err = GetDefaultFactory()
+		f, err = GetDefaultFactory(ic)
 		if err != nil {
 			return nil, err
 		}
 	}
-	return f.New(ctx, InitConfig{
-		Name:      name,
-		DockerAPI: api,
-	})
+	return f.New(ctx, ic)
 }