Merge pull request #281 from laurazard/validate-service-dependents

Validate depended-on services exist in consistency check

loader/validate.go

@@ -38,6 +38,12 @@ func checkConsistency(project *types.Project) error {
 			}
 		}
 
+		for dependedService := range s.DependsOn {
+			if _, err := project.GetService(dependedService); err != nil {
+				return errors.Wrap(errdefs.ErrInvalid, fmt.Sprintf("service %q depends on undefined service %s", s.Name, dependedService))
+			}
+		}
+
 		if strings.HasPrefix(s.NetworkMode, types.ServicePrefix) {
 			serviceName := s.NetworkMode[len(types.ServicePrefix):]
 			if _, err := project.GetServices(serviceName); err != nil {

loader/validate_test.go

@@ -184,3 +184,19 @@ func TestValidateSecret(t *testing.T) {
 		assert.Error(t, err, "secret \"foo\" must declare either `file` or `environment`: invalid compose project")
 	})
 }
+
+func TestValidateDependsOn(t *testing.T) {
+	project := types.Project{
+		Services: types.Services([]types.ServiceConfig{
+			{
+				Name:  "myservice",
+				Image: "scratch",
+				DependsOn: map[string]types.ServiceDependency{
+					"missingservice": {},
+				},
+			},
+		}),
+	}
+	err := checkConsistency(&project)
+	assert.Error(t, err, `service "myservice" depends on undefined service missingservice: invalid compose project`)
+}