Merge pull request #50 from buildpacks/ephemeral-network

Launch build containers in a separate ephemeral Docker bridge network

Author: Natalie Arellano

internal/build/docker.go

@@ -23,6 +23,8 @@ type DockerClient interface {
 	ContainerInspect(ctx context.Context, container string) (types.ContainerJSON, error)
 	ContainerRemove(ctx context.Context, container string, options containertypes.RemoveOptions) error
 	CopyToContainer(ctx context.Context, container, path string, content io.Reader, options types.CopyToContainerOptions) error
+	NetworkCreate(ctx context.Context, name string, options types.NetworkCreate) (types.NetworkCreateResponse, error)
+	NetworkRemove(ctx context.Context, network string) error
 }
 
 var _ DockerClient = dockerClient.CommonAPIClient(nil)

internal/build/lifecycle_execution.go

@@ -12,6 +12,7 @@ import (
 	"github.com/buildpacks/lifecycle/api"
 	"github.com/buildpacks/lifecycle/auth"
 	"github.com/buildpacks/lifecycle/platform/files"
+	"github.com/docker/docker/api/types"
 	"github.com/google/go-containerregistry/pkg/name"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
@@ -165,6 +166,7 @@ func (l *LifecycleExecution) PrevImageName() string {
 
 func (l *LifecycleExecution) Run(ctx context.Context, phaseFactoryCreator PhaseFactoryCreator) error {
 	phaseFactory := phaseFactoryCreator(l)
+
 	var buildCache Cache
 	if l.opts.CacheImage != "" || (l.opts.Cache.Build.Format == cache.CacheImage) {
 		cacheImageName := l.opts.CacheImage
@@ -196,6 +198,29 @@ func (l *LifecycleExecution) Run(ctx context.Context, phaseFactoryCreator PhaseF
 
 	launchCache := cache.NewVolumeCache(l.opts.Image, l.opts.Cache.Launch, "launch", l.docker)
 
+	if l.opts.Network == "" {
+		// start an ephemeral bridge network
+		driver := "bridge"
+		if l.os == "windows" {
+			driver = "nat"
+		}
+		networkName := fmt.Sprintf("pack.local/network/%x", randString(10))
+		resp, err := l.docker.NetworkCreate(ctx, networkName, types.NetworkCreate{
+			Driver: driver,
+		})
+		if err != nil {
+			return fmt.Errorf("failed to create ephemeral %s network: %w", driver, err)
+		}
+		defer func() {
+			_ = l.docker.NetworkRemove(ctx, networkName)
+		}()
+		l.logger.Debugf("Created ephemeral bridge network %s with ID %s", networkName, resp.ID)
+		if resp.Warning != "" {
+			l.logger.Warn(resp.Warning)
+		}
+		l.opts.Network = networkName
+	}
+
 	if !l.opts.UseCreator {
 		if l.platformAPI.LessThan("0.7") {
 			l.logger.Info(style.Step("DETECTING"))

internal/build/lifecycle_execution_test.go

@@ -16,6 +16,7 @@ import (
 	ifakes "github.com/buildpacks/imgutil/fakes"
 	"github.com/buildpacks/lifecycle/api"
 	"github.com/buildpacks/lifecycle/platform/files"
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/client"
 	"github.com/google/go-containerregistry/pkg/authn"
@@ -275,7 +276,7 @@ func testLifecycleExecution(t *testing.T, when spec.G, it spec.S) {
 			fakeBuilder *fakes.FakeBuilder
 			outBuf      bytes.Buffer
 			logger      *logging.LogWithWriters
-			docker      *client.Client
+			docker      *fakeDockerClient
 			fakeTermui  *fakes.FakeTermui
 		)
 
@@ -289,7 +290,7 @@ func testLifecycleExecution(t *testing.T, when spec.G, it spec.S) {
 			fakeBuilder, err = fakes.NewFakeBuilder(fakes.WithSupportedPlatformAPIs([]*api.Version{api.MustParse("0.3")}))
 			h.AssertNil(t, err)
 			logger = logging.NewLogWithWriters(&outBuf, &outBuf)
-			docker, err = client.NewClientWithOpts(client.FromEnv, client.WithVersion("1.38"))
+			docker = &fakeDockerClient{}
 			h.AssertNil(t, err)
 			fakePhaseFactory = fakes.NewFakePhaseFactory()
 		})
@@ -780,6 +781,46 @@ func testLifecycleExecution(t *testing.T, when spec.G, it spec.S) {
 			})
 		})
 
+		when("network is not provided", func() {
+			it("creates an ephemeral bridge network", func() {
+				beforeNetworks := func() int {
+					networks, err := docker.NetworkList(context.Background(), types.NetworkListOptions{})
+					h.AssertNil(t, err)
+					return len(networks)
+				}()
+
+				opts := build.LifecycleOptions{
+					Image:   imageName,
+					Builder: fakeBuilder,
+					Termui:  fakeTermui,
+				}
+
+				lifecycle, err := build.NewLifecycleExecution(logger, docker, "some-temp-dir", opts)
+				h.AssertNil(t, err)
+
+				err = lifecycle.Run(context.Background(), func(execution *build.LifecycleExecution) build.PhaseFactory {
+					return fakePhaseFactory
+				})
+				h.AssertNil(t, err)
+
+				for _, entry := range fakePhaseFactory.NewCalledWithProvider {
+					h.AssertContains(t, string(entry.HostConfig().NetworkMode), "pack.local/network/")
+					h.AssertEq(t, entry.HostConfig().NetworkMode.IsDefault(), false)
+					h.AssertEq(t, entry.HostConfig().NetworkMode.IsHost(), false)
+					h.AssertEq(t, entry.HostConfig().NetworkMode.IsNone(), false)
+					h.AssertEq(t, entry.HostConfig().NetworkMode.IsPrivate(), true)
+					h.AssertEq(t, entry.HostConfig().NetworkMode.IsUserDefined(), true)
+				}
+
+				afterNetworks := func() int {
+					networks, err := docker.NetworkList(context.Background(), types.NetworkListOptions{})
+					h.AssertNil(t, err)
+					return len(networks)
+				}()
+				h.AssertEq(t, beforeNetworks, afterNetworks)
+			})
+		})
+
 		when("Error cases", func() {
 			when("passed invalid", func() {
 				it("fails for cache-image", func() {
@@ -2657,6 +2698,26 @@ func (f *fakeImageFetcher) fetchRunImage(name string) error {
 	return nil
 }
 
+type fakeDockerClient struct {
+	nNetworks int
+	build.DockerClient
+}
+
+func (f *fakeDockerClient) NetworkList(ctx context.Context, opts types.NetworkListOptions) ([]types.NetworkResource, error) {
+	ret := make([]types.NetworkResource, f.nNetworks)
+	return ret, nil
+}
+
+func (f *fakeDockerClient) NetworkCreate(ctx context.Context, name string, options types.NetworkCreate) (types.NetworkCreateResponse, error) {
+	f.nNetworks++
+	return types.NetworkCreateResponse{}, nil
+}
+
+func (f *fakeDockerClient) NetworkRemove(ctx context.Context, network string) error {
+	f.nNetworks--
+	return nil
+}
+
 func newTestLifecycleExecErr(t *testing.T, logVerbose bool, tmpDir string, ops ...func(*build.LifecycleOptions)) (*build.LifecycleExecution, error) {
 	docker, err := client.NewClientWithOpts(client.FromEnv, client.WithVersion("1.38"))
 	h.AssertNil(t, err)

pkg/client/docker.go

@@ -32,4 +32,6 @@ type DockerClient interface {
 	ContainerWait(ctx context.Context, container string, condition containertypes.WaitCondition) (<-chan containertypes.WaitResponse, <-chan error)
 	ContainerAttach(ctx context.Context, container string, options containertypes.AttachOptions) (types.HijackedResponse, error)
 	ContainerStart(ctx context.Context, container string, options containertypes.StartOptions) error
+	NetworkCreate(ctx context.Context, name string, options types.NetworkCreate) (types.NetworkCreateResponse, error)
+	NetworkRemove(ctx context.Context, network string) error
 }