driver: allow setting buildkit config file

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Co-Authored-By: Tibor Vass <tiborvass@users.noreply.github.com>

driver/docker-container/driver.go

@@ -1,6 +1,8 @@
 package docker
 
 import (
+	"archive/tar"
+	"bytes"
 	"context"
 	"io"
 	"io/ioutil"
@@ -74,6 +76,15 @@ func (d *Driver) create(ctx context.Context, l progress.SubLogger) error {
 		if err != nil {
 			return err
 		}
+		if f := d.InitConfig.ConfigFile; f != "" {
+			buf, err := readFileToTar(f)
+			if err != nil {
+				return err
+			}
+			if err := d.DockerAPI.CopyToContainer(ctx, d.Name, "/", buf, dockertypes.CopyToContainerOptions{}); err != nil {
+				return err
+			}
+		}
 		if err := d.start(ctx, l); err != nil {
 			return err
 		}
@@ -245,3 +256,26 @@ type demux struct {
 func (d *demux) Read(dt []byte) (int, error) {
 	return d.Reader.Read(dt)
 }
+
+func readFileToTar(fn string) (*bytes.Buffer, error) {
+	buf := bytes.NewBuffer(nil)
+	tw := tar.NewWriter(buf)
+	dt, err := ioutil.ReadFile(fn)
+	if err != nil {
+		return nil, err
+	}
+	if err := tw.WriteHeader(&tar.Header{
+		Name: "/etc/buildkit/buildkitd.toml",
+		Size: int64(len(dt)),
+		Mode: 0644,
+	}); err != nil {
+		return nil, err
+	}
+	if _, err := tw.Write(dt); err != nil {
+		return nil, err
+	}
+	if err := tw.Close(); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}

driver/docker/factory.go

@@ -44,6 +44,9 @@ func (f *factory) New(ctx context.Context, cfg driver.InitConfig) (driver.Driver
 	if cfg.DockerAPI == nil {
 		return nil, errors.Errorf("docker driver requires docker API access")
 	}
+	if cfg.ConfigFile != "" {
+		return nil, errors.Errorf("setting config file is not supported for docker driver, use dockerd configuration file")
+	}
 
 	return &Driver{factory: f, InitConfig: cfg}, nil
 }

driver/manager.go

@@ -26,6 +26,7 @@ type InitConfig struct {
 	Name          string
 	DockerAPI     dockerclient.APIClient
 	BuildkitFlags []string
+	ConfigFile    string
 	Meta          map[string]interface{}
 }
 
@@ -71,11 +72,12 @@ func GetFactory(name string, instanceRequired bool) Factory {
 	return nil
 }
 
-func GetDriver(ctx context.Context, name string, f Factory, api dockerclient.APIClient, flags []string) (Driver, error) {
+func GetDriver(ctx context.Context, name string, f Factory, api dockerclient.APIClient, flags []string, config string) (Driver, error) {
 	ic := InitConfig{
 		DockerAPI:     api,
 		Name:          name,
 		BuildkitFlags: flags,
+		ConfigFile:    config,
 	}
 	if f == nil {
 		var err error