builder: setup code for a bridge networking

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

builder/builder-next/builder.go

@@ -15,6 +15,7 @@ import (
 	"github.com/docker/docker/daemon/images"
 	"github.com/docker/docker/pkg/streamformatter"
 	"github.com/docker/docker/pkg/system"
+	"github.com/docker/libnetwork"
 	controlapi "github.com/moby/buildkit/api/services/control"
 	"github.com/moby/buildkit/control"
 	"github.com/moby/buildkit/identity"
@@ -27,9 +28,10 @@ import (
 
 // Opt is option struct required for creating the builder
 type Opt struct {
-	SessionManager *session.Manager
-	Root           string
-	Dist           images.DistributionServices
+	SessionManager    *session.Manager
+	Root              string
+	Dist              images.DistributionServices
+	NetworkController libnetwork.NetworkController
 }
 
 // Builder can build using BuildKit backend

builder/builder-next/controller.go

@@ -90,7 +90,7 @@ func newController(rt http.RoundTripper, opt Opt) (*control.Controller, error) {
 		return nil, err
 	}
 
-	exec, err := newExecutor(root)
+	exec, err := newExecutor(root, opt.NetworkController)
 	if err != nil {
 		return nil, err
 	}

builder/builder-next/executor_unix.go

@@ -3,15 +3,108 @@
 package buildkit
 
 import (
+	"fmt"
 	"path/filepath"
+	"sync"
 
+	"github.com/docker/libnetwork"
 	"github.com/moby/buildkit/executor"
 	"github.com/moby/buildkit/executor/runcexecutor"
+	"github.com/moby/buildkit/identity"
+	"github.com/moby/buildkit/util/network"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 )
 
-func newExecutor(root string) (executor.Executor, error) {
+const networkName = "bridge"
+
+func newExecutor(root string, net libnetwork.NetworkController) (executor.Executor, error) {
 	return runcexecutor.New(runcexecutor.Opt{
 		Root:              filepath.Join(root, "executor"),
 		CommandCandidates: []string{"docker-runc", "runc"},
-	})
+	}, &bridgeProvider{NetworkController: net})
+}
+
+type bridgeProvider struct {
+	libnetwork.NetworkController
+}
+
+func (p *bridgeProvider) NewInterface() (network.Interface, error) {
+	n, err := p.NetworkByName(networkName)
+	if err != nil {
+		return nil, err
+	}
+
+	iface := &lnInterface{ready: make(chan struct{})}
+	iface.Once.Do(func() {
+		go iface.init(p.NetworkController, n)
+	})
+
+	return iface, nil
+}
+
+func (p *bridgeProvider) Release(iface network.Interface) error {
+	go func() {
+		if err := p.release(iface); err != nil {
+			logrus.Errorf("%s", err)
+		}
+	}()
+	return nil
+}
+
+func (p *bridgeProvider) release(iface network.Interface) error {
+	li, ok := iface.(*lnInterface)
+	if !ok {
+		return errors.Errorf("invalid interface %T", iface)
+	}
+	err := li.sbx.Delete()
+	if err1 := li.ep.Delete(true); err1 != nil && err == nil {
+		err = err1
+	}
+	return err
+}
+
+type lnInterface struct {
+	ep  libnetwork.Endpoint
+	sbx libnetwork.Sandbox
+	sync.Once
+	err   error
+	ready chan struct{}
+}
+
+func (iface *lnInterface) init(c libnetwork.NetworkController, n libnetwork.Network) {
+	defer close(iface.ready)
+	id := identity.NewID()
+
+	ep, err := n.CreateEndpoint(id)
+	if err != nil {
+		iface.err = err
+		return
+	}
+
+	sbx, err := c.NewSandbox(id)
+	if err != nil {
+		iface.err = err
+		return
+	}
+
+	if err := ep.Join(sbx); err != nil {
+		iface.err = err
+		return
+	}
+
+	iface.sbx = sbx
+	iface.ep = ep
+}
+
+func (iface *lnInterface) Set(pid int) error {
+	<-iface.ready
+	if iface.err != nil {
+		return iface.err
+	}
+	return iface.sbx.SetKey(fmt.Sprintf("/proc/%d/ns/net", pid))
+}
+
+func (iface *lnInterface) Remove(pid int) error {
+	return nil
 }

builder/builder-next/executor_windows.go

@@ -5,11 +5,12 @@ import (
 	"errors"
 	"io"
 
+	"github.com/docker/libnetwork"
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/executor"
 )
 
-func newExecutor(_ string) (executor.Executor, error) {
+func newExecutor(_ string, _ libnetwork.NetworkController) (executor.Executor, error) {
 	return &winExecutor{}, nil
 }
 

cmd/dockerd/daemon.go

@@ -286,9 +286,10 @@ func newRouterOptions(config *config.Config, daemon *daemon.Daemon) (routerOptio
 		return opts, err
 	}
 	bk, err := buildkit.New(buildkit.Opt{
-		SessionManager: sm,
-		Root:           filepath.Join(config.Root, "buildkit"),
-		Dist:           daemon.DistributionServices(),
+		SessionManager:    sm,
+		Root:              filepath.Join(config.Root, "buildkit"),
+		Dist:              daemon.DistributionServices(),
+		NetworkController: daemon.NetworkController(),
 	})
 	if err != nil {
 		return opts, err

daemon/network.go

@@ -49,6 +49,11 @@ func (daemon *Daemon) NetworkControllerEnabled() bool {
 	return daemon.netController != nil
 }
 
+// NetworkController returns the network controller created by the daemon.
+func (daemon *Daemon) NetworkController() libnetwork.NetworkController {
+	return daemon.netController
+}
+
 // FindNetwork returns a network based on:
 // 1. Full ID
 // 2. Full Name