test: docker host-gateway

Dockerfile

@@ -3,7 +3,7 @@
 ARG GO_VERSION=1.20.8
 ARG XX_VERSION=1.2.1
 
-ARG DOCKER_VERSION=24.0.2
+ARG DOCKER_VERSION=24.0.6
 ARG GOTESTSUM_VERSION=v1.9.0
 ARG REGISTRY_VERSION=2.8.0
 ARG BUILDKIT_VERSION=v0.11.6

tests/build.go

@@ -47,6 +47,7 @@ var buildTests = []func(t *testing.T, sb integration.Sandbox){
 	testBuildCacheExportNotSupported,
 	testBuildOCIExportNotSupported,
 	testBuildMultiPlatformNotSupported,
+	testDockerHostGateway,
 }
 
 func testBuild(t *testing.T, sb integration.Sandbox) {
@@ -415,3 +416,19 @@ func testBuildMultiPlatformNotSupported(t *testing.T, sb integration.Sandbox) {
 	require.Error(t, err, string(out))
 	require.Contains(t, string(out), "Multi-platform build is not supported")
 }
+
+func testDockerHostGateway(t *testing.T, sb integration.Sandbox) {
+	dockerfile := []byte(`
+FROM busybox
+RUN ping -c 1 buildx.host-gateway-ip.local
+`)
+	dir := tmpdir(t, fstest.CreateFile("Dockerfile", dockerfile, 0600))
+	cmd := buildxCmd(sb, withArgs("build", "--add-host=buildx.host-gateway-ip.local:host-gateway", "--output=type=cacheonly", dir))
+	out, err := cmd.CombinedOutput()
+	if !isDockerWorker(sb) {
+		require.Error(t, err, string(out))
+		require.Contains(t, string(out), "host-gateway is not supported")
+	} else {
+		require.NoError(t, err, string(out))
+	}
+}

tests/inspect.go

@@ -25,16 +25,25 @@ func testInspect(t *testing.T, sb integration.Sandbox) {
 
 	var name string
 	var driver string
+	var hostGatewayIP string
 	for _, line := range strings.Split(out, "\n") {
 		if v, ok := strings.CutPrefix(line, "Name:"); ok && name == "" {
 			name = strings.TrimSpace(v)
 		}
 		if v, ok := strings.CutPrefix(line, "Driver:"); ok && driver == "" {
 			driver = strings.TrimSpace(v)
 		}
+		if v, ok := strings.CutPrefix(line, " org.mobyproject.buildkit.worker.moby.host-gateway-ip:"); ok {
+			hostGatewayIP = strings.TrimSpace(v)
+		}
 	}
 
 	require.Equal(t, sb.Address(), name)
 	sbDriver, _, _ := strings.Cut(sb.Name(), "+")
 	require.Equal(t, sbDriver, driver)
+	if isDockerWorker(sb) {
+		require.NotEmpty(t, hostGatewayIP, "host-gateway-ip worker label should be set with docker driver")
+	} else {
+		require.Empty(t, hostGatewayIP, "host-gateway-ip worker label should not be set with non-docker driver")
+	}
 }