Added transforms for compose overrides

Added transforms for when merging compose overrides to preserve the
functionality that was broken by bumping mergo to v1.3.8

This includes:
- Special transform for ulimits so single overrides both soft/hard and
the reverse
- Special transform for service network configs so the override replaces
all aliases

Signed-off-by: Nick Adcock <nick.adcock@docker.com>

cli/compose/loader/merge.go

@@ -57,6 +57,8 @@ func mergeServices(base, override []types.ServiceConfig) ([]types.ServiceConfig,
 			reflect.TypeOf([]types.ServicePortConfig{}):      mergeSlice(toServicePortConfigsMap, toServicePortConfigsSlice),
 			reflect.TypeOf([]types.ServiceSecretConfig{}):    mergeSlice(toServiceSecretConfigsMap, toServiceSecretConfigsSlice),
 			reflect.TypeOf([]types.ServiceConfigObjConfig{}): mergeSlice(toServiceConfigObjConfigsMap, toSServiceConfigObjConfigsSlice),
+			reflect.TypeOf(&types.UlimitsConfig{}):           mergeUlimitsConfig,
+			reflect.TypeOf(&types.ServiceNetworkConfig{}):    mergeServiceNetworkConfig,
 		},
 	}
 	for name, overrideService := range overrideServices {
@@ -201,6 +203,28 @@ func mergeLoggingConfig(dst, src reflect.Value) error {
 	return nil
 }
 
+//nolint: unparam
+func mergeUlimitsConfig(dst, src reflect.Value) error {
+	if src.Interface() != reflect.Zero(reflect.TypeOf(src.Interface())).Interface() {
+		dst.Elem().Set(src.Elem())
+	}
+	return nil
+}
+
+//nolint: unparam
+func mergeServiceNetworkConfig(dst, src reflect.Value) error {
+	if src.Interface() != reflect.Zero(reflect.TypeOf(src.Interface())).Interface() {
+		dst.Elem().FieldByName("Aliases").Set(src.Elem().FieldByName("Aliases"))
+		if ipv4 := src.Elem().FieldByName("Ipv4Address").Interface().(string); ipv4 != "" {
+			dst.Elem().FieldByName("Ipv4Address").SetString(ipv4)
+		}
+		if ipv6 := src.Elem().FieldByName("Ipv6Address").Interface().(string); ipv6 != "" {
+			dst.Elem().FieldByName("Ipv6Address").SetString(ipv6)
+		}
+	}
+	return nil
+}
+
 func getLoggingDriver(v reflect.Value) string {
 	return v.FieldByName("Driver").String()
 }

cli/compose/loader/merge_test.go

@@ -1,9 +1,11 @@
 package loader
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/docker/cli/cli/compose/types"
+	"github.com/imdario/mergo"
 	"gotest.tools/assert"
 )
 
@@ -1014,3 +1016,94 @@ func TestLoadMultipleNetworks(t *testing.T) {
 		Configs: map[string]types.ConfigObjConfig{},
 	}, config)
 }
+
+func TestMergeUlimitsConfig(t *testing.T) {
+	specials := &specials{
+		m: map[reflect.Type]func(dst, src reflect.Value) error{
+			reflect.TypeOf(&types.UlimitsConfig{}): mergeUlimitsConfig,
+		},
+	}
+	base := map[string]*types.UlimitsConfig{
+		"override-single":                &types.UlimitsConfig{Single: 100},
+		"override-single-with-soft-hard": &types.UlimitsConfig{Single: 200},
+		"override-soft-hard":             &types.UlimitsConfig{Soft: 300, Hard: 301},
+		"override-soft-hard-with-single": &types.UlimitsConfig{Soft: 400, Hard: 401},
+		"dont-override":                  &types.UlimitsConfig{Single: 500},
+	}
+	override := map[string]*types.UlimitsConfig{
+		"override-single":                &types.UlimitsConfig{Single: 110},
+		"override-single-with-soft-hard": &types.UlimitsConfig{Soft: 210, Hard: 211},
+		"override-soft-hard":             &types.UlimitsConfig{Soft: 310, Hard: 311},
+		"override-soft-hard-with-single": &types.UlimitsConfig{Single: 410},
+		"add":                            &types.UlimitsConfig{Single: 610},
+	}
+	err := mergo.Merge(&base, &override, mergo.WithOverride, mergo.WithTransformers(specials))
+	assert.NilError(t, err)
+	assert.DeepEqual(
+		t,
+		base,
+		map[string]*types.UlimitsConfig{
+			"override-single":                &types.UlimitsConfig{Single: 110},
+			"override-single-with-soft-hard": &types.UlimitsConfig{Soft: 210, Hard: 211},
+			"override-soft-hard":             &types.UlimitsConfig{Soft: 310, Hard: 311},
+			"override-soft-hard-with-single": &types.UlimitsConfig{Single: 410},
+			"dont-override":                  &types.UlimitsConfig{Single: 500},
+			"add":                            &types.UlimitsConfig{Single: 610},
+		},
+	)
+}
+
+func TestMergeServiceNetworkConfig(t *testing.T) {
+	specials := &specials{
+		m: map[reflect.Type]func(dst, src reflect.Value) error{
+			reflect.TypeOf(&types.ServiceNetworkConfig{}): mergeServiceNetworkConfig,
+		},
+	}
+	base := map[string]*types.ServiceNetworkConfig{
+		"override-aliases": &types.ServiceNetworkConfig{
+			Aliases:     []string{"100", "101"},
+			Ipv4Address: "127.0.0.1",
+			Ipv6Address: "0:0:0:0:0:0:0:1",
+		},
+		"dont-override": &types.ServiceNetworkConfig{
+			Aliases:     []string{"200", "201"},
+			Ipv4Address: "127.0.0.2",
+			Ipv6Address: "0:0:0:0:0:0:0:2",
+		},
+	}
+	override := map[string]*types.ServiceNetworkConfig{
+		"override-aliases": &types.ServiceNetworkConfig{
+			Aliases:     []string{"110", "111"},
+			Ipv4Address: "127.0.1.1",
+			Ipv6Address: "0:0:0:0:0:0:1:1",
+		},
+		"add": &types.ServiceNetworkConfig{
+			Aliases:     []string{"310", "311"},
+			Ipv4Address: "127.0.3.1",
+			Ipv6Address: "0:0:0:0:0:0:3:1",
+		},
+	}
+	err := mergo.Merge(&base, &override, mergo.WithOverride, mergo.WithTransformers(specials))
+	assert.NilError(t, err)
+	assert.DeepEqual(
+		t,
+		base,
+		map[string]*types.ServiceNetworkConfig{
+			"override-aliases": &types.ServiceNetworkConfig{
+				Aliases:     []string{"110", "111"},
+				Ipv4Address: "127.0.1.1",
+				Ipv6Address: "0:0:0:0:0:0:1:1",
+			},
+			"dont-override": &types.ServiceNetworkConfig{
+				Aliases:     []string{"200", "201"},
+				Ipv4Address: "127.0.0.2",
+				Ipv6Address: "0:0:0:0:0:0:0:2",
+			},
+			"add": &types.ServiceNetworkConfig{
+				Aliases:     []string{"310", "311"},
+				Ipv4Address: "127.0.3.1",
+				Ipv6Address: "0:0:0:0:0:0:3:1",
+			},
+		},
+	)
+}