Set NetworkMode correctly according to network priorities

Signed-off-by: Laura Brehm <laurabrehm@hey.com>

pkg/compose/create.go

@@ -447,7 +447,7 @@ func (s *composeService) prepareLabels(p *types.Project, service types.ServiceCo
 func getDefaultNetworkMode(project *types.Project, service types.ServiceConfig) string {
 	mode := "none"
 	if len(project.Networks) > 0 {
-		for name := range getNetworksForService(service) {
+		for _, name := range service.NetworksByPriority() {
 			mode = project.Networks[name].Name
 			break
 		}

pkg/compose/create_test.go

@@ -151,3 +151,33 @@ func TestGetBindMode(t *testing.T) {
 	assert.Equal(t, getBindMode(&composetypes.ServiceVolumeBind{SELinux: composetypes.SELinuxShared}, true), "ro,z")
 	assert.Equal(t, getBindMode(&composetypes.ServiceVolumeBind{SELinux: composetypes.SELinuxPrivate}, true), "ro,Z")
 }
+
+func TestGetDefaultNetworkMode(t *testing.T) {
+	service := composetypes.ServiceConfig{
+		Name: "myService",
+		Networks: map[string]*composetypes.ServiceNetworkConfig{
+			"myNetwork1": {
+				Priority: 10,
+			},
+			"myNetwork2": {
+				Priority: 1000,
+			},
+		},
+	}
+	project := composetypes.Project{
+		Name: "myProject",
+		Services: []composetypes.ServiceConfig{
+			service,
+		},
+		Networks: composetypes.Networks(map[string]composetypes.NetworkConfig{
+			"myNetwork1": {
+				Name: "myProject_myNetwork1",
+			},
+			"myNetwork2": {
+				Name: "myProject_myNetwork2",
+			},
+		}),
+	}
+
+	assert.Equal(t, getDefaultNetworkMode(&project, service), "myProject_myNetwork2")
+}