From 04472c7552733ad31a8ebad58d238455c9f184b5 Mon Sep 17 00:00:00 2001
From: Ivan Mikushin <i.mikushin@gmail.com>
Date: Wed, 26 Aug 2015 14:48:19 +0500
Subject: [PATCH] Do not link to services that do not exist in the project

Fixes #495
---
 docker/service.go         | 17 +++++++++++------
 docker/service_factory.go |  2 +-
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/docker/service.go b/docker/service.go
index 62cb8204..0930a327 100644
--- a/docker/service.go
+++ b/docker/service.go
@@ -14,32 +14,34 @@ type Service struct {
 	*docker.Service
 	deps    map[string][]string
 	context *docker.Context
+	project *project.Project
 }
 
-func NewService(factory *ServiceFactory, name string, serviceConfig *project.ServiceConfig, context *docker.Context) *Service {
+func NewService(factory *ServiceFactory, name string, serviceConfig *project.ServiceConfig, context *docker.Context, project *project.Project) *Service {
 	return &Service{
 		Service: docker.NewService(name, serviceConfig, context),
 		deps:    factory.Deps,
 		context: context,
+		project: project,
 	}
 }
 
 func (s *Service) DependentServices() []project.ServiceRelationship {
 	rels := s.Service.DependentServices()
 	for _, dep := range s.deps[s.Name()] {
-		rels = appendLink(rels, dep, true)
+		rels = appendLink(rels, dep, true, s.project)
 	}
 
 	if s.requiresSyslog() {
-		rels = appendLink(rels, "syslog", false)
+		rels = appendLink(rels, "syslog", false, s.project)
 	}
 
 	if s.requiresUserDocker() {
 		// Linking to cloud-init is a hack really.  The problem is we need to link to something
 		// that will trigger a reload
-		rels = appendLink(rels, "cloud-init", false)
+		rels = appendLink(rels, "cloud-init", false, s.project)
 	} else if s.missingImage() {
-		rels = appendLink(rels, "network", false)
+		rels = appendLink(rels, "network", false, s.project)
 	}
 	return rels
 }
@@ -62,7 +64,10 @@ func (s *Service) requiresUserDocker() bool {
 	return s.Config().Labels.MapParts()[config.SCOPE] != config.SYSTEM
 }
 
-func appendLink(deps []project.ServiceRelationship, name string, optional bool) []project.ServiceRelationship {
+func appendLink(deps []project.ServiceRelationship, name string, optional bool, p *project.Project) []project.ServiceRelationship {
+	if _, ok := p.Configs[name]; !ok {
+		return deps
+	}
 	rel := project.NewServiceRelationship(name, project.REL_TYPE_LINK)
 	rel.Optional = optional
 	return append(deps, rel)
diff --git a/docker/service_factory.go b/docker/service_factory.go
index cedcef0c..ff4b4a5d 100644
--- a/docker/service_factory.go
+++ b/docker/service_factory.go
@@ -23,5 +23,5 @@ func (s *ServiceFactory) Create(project *project.Project, name string, serviceCo
 		}
 	}
 
-	return NewService(s, name, serviceConfig, s.Context), nil
+	return NewService(s, name, serviceConfig, s.Context, project), nil
 }