Move docker specific volume & network settings into backend code (#1956)

... if we want to make them be changed ... it should be an
agent-backend-option

pipeline/backend/docker/docker.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"io"
 	"os"
+	"runtime"
 	"strings"
 
 	"github.com/docker/docker/api/types"
@@ -41,6 +42,12 @@ type docker struct {
 	volumes    []string
 }
 
+const (
+	networkDriverNAT    = "nat"
+	networkDriverBridge = "bridge"
+	volumeDriver        = "local"
+)
+
 // New returns a new Docker Engine.
 func New() backend.Engine {
 	return &docker{
@@ -97,21 +104,22 @@ func (e *docker) Load(ctx context.Context) error {
 func (e *docker) Setup(_ context.Context, conf *backend.Config) error {
 	for _, vol := range conf.Volumes {
 		_, err := e.client.VolumeCreate(noContext, volume.VolumeCreateBody{
-			Name:       vol.Name,
-			Driver:     vol.Driver,
-			DriverOpts: vol.DriverOpts,
-			// Labels:     defaultLabels,
+			Name:   vol.Name,
+			Driver: volumeDriver,
 		})
 		if err != nil {
 			return err
 		}
 	}
+
+	networkDriver := networkDriverBridge
+	if runtime.GOOS == "windows" {
+		networkDriver = networkDriverNAT
+	}
 	for _, n := range conf.Networks {
 		_, err := e.client.NetworkCreate(noContext, n.Name, types.NetworkCreate{
-			Driver:     n.Driver,
-			Options:    n.DriverOpts,
+			Driver:     networkDriver,
 			EnableIPv6: e.enableIPv6,
-			// Labels:  defaultLabels,
 		})
 		if err != nil {
 			return err