docker-container: allow using host network

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

driver/docker-container/driver.go

@@ -27,6 +27,7 @@ var buildkitImage = "moby/buildkit:master" // TODO: make this verified and confi
 type Driver struct {
 	driver.InitConfig
 	factory driver.Factory
+	netMode string
 }
 
 func (d *Driver) Bootstrap(ctx context.Context, l progress.Logger) error {
@@ -70,9 +71,13 @@ func (d *Driver) create(ctx context.Context, l progress.SubLogger) error {
 	}
 
 	if err := l.Wrap("creating container "+d.Name, func() error {
-		_, err := d.DockerAPI.ContainerCreate(ctx, cfg, &container.HostConfig{
+		hc := &container.HostConfig{
 			Privileged: true,
-		}, &network.NetworkingConfig{}, d.Name)
+		}
+		if d.netMode != "" {
+			hc.NetworkMode = container.NetworkMode(d.netMode)
+		}
+		_, err := d.DockerAPI.ContainerCreate(ctx, cfg, hc, &network.NetworkingConfig{}, d.Name)
 		if err != nil {
 			return err
 		}

driver/docker-container/factory.go

@@ -37,8 +37,20 @@ func (f *factory) New(ctx context.Context, cfg driver.InitConfig) (driver.Driver
 	if cfg.DockerAPI == nil {
 		return nil, errors.Errorf("%s driver requires docker API access", f.Name())
 	}
+	d := &Driver{factory: f, InitConfig: cfg}
+	for k, v := range cfg.DriverOpts {
+		switch k {
+		case "network":
+			d.netMode = v
+			if v == "host" {
+				d.InitConfig.BuildkitFlags = append(d.InitConfig.BuildkitFlags, "--allow-insecure-entitlement=network.host")
+			}
+		default:
+			return nil, errors.Errorf("invalid driver option %s for docker-container driver")
+		}
+	}
 
-	return &Driver{factory: f, InitConfig: cfg}, nil
+	return d, nil
 }
 
 func (f *factory) AllowsInstances() bool {