driver: test bridge network mode

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

tests/build.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"net"
 	"os"
 	"path"
 	"path/filepath"
@@ -15,6 +16,7 @@ import (
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/continuity/fs/fstest"
 	"github.com/creack/pty"
+	"github.com/moby/buildkit/util/appdefaults"
 	"github.com/moby/buildkit/util/contentutil"
 	"github.com/moby/buildkit/util/testutil"
 	"github.com/moby/buildkit/util/testutil/integration"
@@ -48,6 +50,7 @@ var buildTests = []func(t *testing.T, sb integration.Sandbox){
 	testBuildOCIExportNotSupported,
 	testBuildMultiPlatformNotSupported,
 	testDockerHostGateway,
+	testBuildNetworkModeBridge,
 }
 
 func testBuild(t *testing.T, sb integration.Sandbox) {
@@ -432,3 +435,54 @@ RUN ping -c 1 buildx.host-gateway-ip.local
 		require.NoError(t, err, string(out))
 	}
 }
+
+func testBuildNetworkModeBridge(t *testing.T, sb integration.Sandbox) {
+	if sb.Name() != "docker" {
+		t.Skip("skipping test for non-docker workers")
+	}
+
+	var builderName string
+	t.Cleanup(func() {
+		if builderName == "" {
+			return
+		}
+		out, err := rmCmd(sb, withArgs(builderName))
+		require.NoError(t, err, out)
+	})
+
+	// TODO: use stable buildkit image when v0.13.0 released
+	out, err := createCmd(sb, withArgs("--driver", "docker-container", "--buildkitd-flags=--oci-worker-net=bridge --allow-insecure-entitlement=network.host", "--driver-opt", "image=moby/buildkit:master"))
+	require.NoError(t, err, out)
+	builderName = strings.TrimSpace(out)
+
+	dockerfile := []byte(`
+FROM busybox AS build
+RUN ip a show eth0 | awk '/inet / {split($2, a, "/"); print a[1]}' > /ip-bridge.txt
+RUN --network=host ip a show eth0 | awk '/inet / {split($2, a, "/"); print a[1]}' > /ip-host.txt
+FROM scratch
+COPY --from=build /ip*.txt /`)
+	dir := tmpdir(t, fstest.CreateFile("Dockerfile", dockerfile, 0600))
+
+	cmd := buildxCmd(sb, withArgs("build", "--allow=network.host", fmt.Sprintf("--output=type=local,dest=%s", dir), dir))
+	cmd.Env = append(cmd.Env, "BUILDX_BUILDER="+builderName)
+	outb, err := cmd.CombinedOutput()
+	require.NoError(t, err, string(outb))
+
+	dt, err := os.ReadFile(filepath.Join(dir, "ip-bridge.txt"))
+	require.NoError(t, err)
+
+	ipBridge := net.ParseIP(strings.TrimSpace(string(dt)))
+	require.NotNil(t, ipBridge)
+
+	_, subnet, err := net.ParseCIDR(appdefaults.BridgeSubnet)
+	require.NoError(t, err)
+	require.True(t, subnet.Contains(ipBridge))
+
+	dt, err = os.ReadFile(filepath.Join(dir, "ip-host.txt"))
+	require.NoError(t, err)
+
+	ip := net.ParseIP(strings.TrimSpace(string(dt)))
+	require.NotNil(t, ip)
+
+	require.NotEqual(t, ip, ipBridge)
+}

tests/inspect.go

@@ -17,6 +17,7 @@ func inspectCmd(sb integration.Sandbox, opts ...cmdOpt) (string, error) {
 
 var inspectTests = []func(t *testing.T, sb integration.Sandbox){
 	testInspect,
+	testInspectBuildkitdFlags,
 }
 
 func testInspect(t *testing.T, sb integration.Sandbox) {
@@ -47,3 +48,33 @@ func testInspect(t *testing.T, sb integration.Sandbox) {
 		require.Empty(t, hostGatewayIP, "host-gateway-ip worker label should not be set with non-docker driver")
 	}
 }
+
+func testInspectBuildkitdFlags(t *testing.T, sb integration.Sandbox) {
+	if sb.Name() != "docker-container" {
+		t.Skip("only testing for docker-container driver")
+	}
+
+	var builderName string
+	t.Cleanup(func() {
+		if builderName == "" {
+			return
+		}
+		out, err := rmCmd(sb, withArgs(builderName))
+		require.NoError(t, err, out)
+	})
+
+	out, err := createCmd(sb, withArgs("--driver", "docker-container", "--buildkitd-flags=--oci-worker-net=bridge"))
+	require.NoError(t, err, out)
+	builderName = strings.TrimSpace(out)
+
+	out, err = inspectCmd(sb, withArgs(builderName))
+	require.NoError(t, err, out)
+
+	for _, line := range strings.Split(out, "\n") {
+		if v, ok := strings.CutPrefix(line, "BuildKit daemon flags:"); ok {
+			require.Contains(t, v, "--oci-worker-net=bridge")
+			return
+		}
+	}
+	require.Fail(t, "--oci-worker-net=bridge not found in inspect output")
+}

tests/integration.go

@@ -47,8 +47,10 @@ func buildxCmd(sb integration.Sandbox, opts ...cmdOpt) *exec.Cmd {
 	}
 
 	if builder := sb.Address(); builder != "" {
-		cmd.Args = append(cmd.Args, "--builder="+builder)
+		cmd.Env = append(cmd.Env,
-		cmd.Env = append(cmd.Env, "BUILDX_CONFIG=/tmp/buildx-"+builder)
+			"BUILDX_CONFIG=/tmp/buildx-"+builder,
+			"BUILDX_BUILDER="+builder,
+		)
 	}
 	if context := sb.DockerAddress(); context != "" {
 		cmd.Env = append(cmd.Env, "DOCKER_CONTEXT="+context)