add depends_on cycle detection during validation phase

loader/loader_test.go

@@ -2552,6 +2552,20 @@ func TestLoadWithIncludeCycle(t *testing.T) {
 	assert.Check(t, strings.HasPrefix(err.Error(), "include cycle detected"))
 }
 
+func TestLoadDependsOnCycle(t *testing.T) {
+	workingDir, err := os.Getwd()
+	assert.NilError(t, err)
+	_, err = LoadWithContext(context.Background(), types.ConfigDetails{
+		WorkingDir: filepath.Join(workingDir, "testdata"),
+		ConfigFiles: []types.ConfigFile{
+			{
+				Filename: filepath.Join(workingDir, "testdata", "compose-depends-on-cycle.yaml"),
+			},
+		},
+	})
+	assert.Error(t, err, "dependency cycle detected: service2 -> service3 -> service1", err)
+}
+
 func TestLoadWithMultipleInclude(t *testing.T) {
 	// include same service twice should not trigger an error
 	p, err := Load(buildConfigDetails(`

loader/testdata/compose-depends-on-cycle.yaml

@@ -0,0 +1,14 @@
+name : depends-on-cycle
+services:
+  service1:
+    image: service1
+    depends_on:
+      - service2
+  service2:
+    image: service2
+    depends_on:
+      - service3
+  service3:
+    image: service3
+    depends_on:
+      - service1

loader/testdata/compose-depends-on-profile-no-cycle.yaml

@@ -0,0 +1,14 @@
+name : depends-on-cycle
+services:
+  service1:
+    image: service1
+    depends_on:
+      - service2
+  service2:
+    image: service2
+    depends_on:
+      - service3
+  service3:
+    image: service3
+    depends_on:
+      - service1

loader/validate.go

@@ -17,11 +17,13 @@
 package loader
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"strings"
 
 	"github.com/compose-spec/compose-go/v2/errdefs"
+	"github.com/compose-spec/compose-go/v2/graph"
 	"github.com/compose-spec/compose-go/v2/types"
 )
 
@@ -73,6 +75,12 @@ func checkConsistency(project *types.Project) error {
 				return fmt.Errorf("service %q depends on undefined service %s: %w", s.Name, dependedService, errdefs.ErrInvalid)
 			}
 		}
+		// Check there isn't a cycle in depends_on declarations
+		if err := graph.InDependencyOrder(context.Background(), project, func(ctx context.Context, s string, config types.ServiceConfig) error {
+			return nil
+		}); err != nil {
+			return err
+		}
 
 		if strings.HasPrefix(s.NetworkMode, types.ServicePrefix) {
 			serviceName := s.NetworkMode[len(types.ServicePrefix):]