compose: do not rely on endpoint ordering for gw_priority

Signed-off-by: pnkcaht <[email protected]>

Author: Pnkcaht

pkg/compose/convergence_test.go

@@ -33,6 +33,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"go.uber.org/mock/gomock"
 	"gotest.tools/v3/assert"
+	"gotest.tools/v3/assert/cmp"
 
 	"github.com/docker/compose/v5/pkg/api"
 	"github.com/docker/compose/v5/pkg/mocks"
@@ -427,7 +428,7 @@ func TestCreateMobyContainer(t *testing.T) {
 	})
 }
 
-func TestDefaultNetworkSettingsOrdersEndpointsByGwPriority(t *testing.T) {
+func TestDefaultNetworkSettingsGwPrioritySelectsPrimaryNetwork(t *testing.T) {
 	project := &types.Project{
 		Name: "test",
 		Networks: map[string]types.NetworkConfig{
@@ -459,16 +460,9 @@ func TestDefaultNetworkSettingsOrdersEndpointsByGwPriority(t *testing.T) {
 	endpoints := netConfig.EndpointsConfig
 	require.Len(t, endpoints, 2)
 
-	keys := make([]string, 0, len(endpoints))
-	for k := range endpoints {
-		keys = append(keys, k)
-	}
-
-	// Highest gw_priority must come first in EndpointsConfig
-	assert.Equal(t, keys[0], "net2")
-	assert.Equal(t, keys[1], "net1")
-
-	// NetworkMode must remain the primary network
-	assert.Equal(t, mode, container.NetworkMode("net1"))
+	assert.Assert(t, cmp.Contains(endpoints, "net1"))
+	assert.Assert(t, cmp.Contains(endpoints, "net2"))
 
+	// gw_priority must only affect primary network selection
+	assert.Assert(t, cmp.Equal(container.NetworkMode("net1"), mode))
 }

pkg/compose/create.go

@@ -25,7 +25,6 @@ import (
 	"os"
 	"path/filepath"
 	"slices"
-	"sort"
 	"strconv"
 	"strings"
 
@@ -569,11 +568,11 @@ func defaultNetworkSettings(project *types.Project,
 		}
 	}
 
-	// Include the primary network before ordering.
+	// Include the primary network
 	endpointsConfig[primaryNetworkMobyNetworkName] = primaryNetworkEndpoint
 
 	networkConfig := &network.NetworkingConfig{
-		EndpointsConfig: orderEndpointsByGwPriority(endpointsConfig),
+		EndpointsConfig: endpointsConfig,
 	}
 
 	// From the Engine API docs:
@@ -582,33 +581,6 @@ func defaultNetworkSettings(project *types.Project,
 	return container.NetworkMode(primaryNetworkMobyNetworkName), networkConfig, nil
 }
 
-type endpointWithName struct {
-	name     string
-	settings *network.EndpointSettings
-}
-
-func orderEndpointsByGwPriority(endpoints map[string]*network.EndpointSettings) map[string]*network.EndpointSettings {
-	if len(endpoints) <= 1 {
-		return endpoints
-	}
-
-	ordered := make([]endpointWithName, 0, len(endpoints))
-	for name, ep := range endpoints {
-		ordered = append(ordered, endpointWithName{name, ep})
-	}
-
-	sort.SliceStable(ordered, func(i, j int) bool {
-		return ordered[i].settings.GwPriority > ordered[j].settings.GwPriority
-	})
-
-	orderedEndpoints := make(map[string]*network.EndpointSettings, len(ordered))
-	for _, ep := range ordered {
-		orderedEndpoints[ep.name] = ep.settings
-	}
-
-	return orderedEndpoints
-}
-
 func getRestartPolicy(service types.ServiceConfig) container.RestartPolicy {
 	var restart container.RestartPolicy
 	if service.Restart != "" {