From f7224ff403c7407e6281b9a344b2f885f544d96e Mon Sep 17 00:00:00 2001
From: Samuel BERTHE <contact@samuel-berthe.fr>
Date: Mon, 6 Jun 2016 21:59:58 +0200
Subject: [PATCH 1/2] feat(constraints): Supports constraints for docker
 backend

---
 docs/toml.md            |  9 +++++++++
 provider/docker.go      | 17 ++++++++++++++---
 provider/docker_test.go |  3 ++-
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/docs/toml.md b/docs/toml.md
index a4886d054..ebc02bc48 100644
--- a/docs/toml.md
+++ b/docs/toml.md
@@ -203,6 +203,7 @@ Træfɪk filters services according to service attributes/tags set in your confi
 
 Supported backends:
 
+- Docker
 - Consul Catalog
 
 Supported filters:
@@ -574,6 +575,14 @@ watch = true
 #  cert = "/etc/ssl/docker.crt"
 #  key = "/etc/ssl/docker.key"
 #  insecureskipverify = true
+
+# Constraint on Docker tags
+#
+# Optional
+#
+# constraints = ["tag==api", "tag==he*ld"]
+# Matching with containers having the label "traefik.tags" set to "api,helloworld"
+# ex: $ docker run -d -P --label traefik.tags=api,helloworld emilevauge/whoami
 ```
 
 Labels can be used on containers to override default behaviour:
diff --git a/provider/docker.go b/provider/docker.go
index 8f2dcfb87..2afeb37c4 100644
--- a/provider/docker.go
+++ b/provider/docker.go
@@ -177,11 +177,12 @@ func (provider *Docker) loadDockerConfig(containersInspected []dockertypes.Conta
 	}
 
 	// filter containers
-	filteredContainers := fun.Filter(containerFilter, containersInspected).([]dockertypes.ContainerJSON)
+	filteredContainers := fun.Filter(provider.ContainerFilter, containersInspected).([]dockertypes.ContainerJSON)
 
 	frontends := map[string][]dockertypes.ContainerJSON{}
 	for _, container := range filteredContainers {
-		frontends[provider.getFrontendName(container)] = append(frontends[provider.getFrontendName(container)], container)
+		frontendName := provider.getFrontendName(container)
+		frontends[frontendName] = append(frontends[frontendName], container)
 	}
 
 	templateObjects := struct {
@@ -201,7 +202,8 @@ func (provider *Docker) loadDockerConfig(containersInspected []dockertypes.Conta
 	return configuration
 }
 
-func containerFilter(container dockertypes.ContainerJSON) bool {
+// ContainerFilter checks if container have to be exposed
+func (provider *Docker) ContainerFilter(container dockertypes.ContainerJSON) bool {
 	_, err := strconv.Atoi(container.Config.Labels["traefik.port"])
 	if len(container.NetworkSettings.Ports) == 0 && err != nil {
 		log.Debugf("Filtering container without port and no traefik.port label %s", container.Name)
@@ -217,6 +219,15 @@ func containerFilter(container dockertypes.ContainerJSON) bool {
 		return false
 	}
 
+	constraintTags := strings.Split(container.Config.Labels["traefik.tags"], ",")
+	ok, failingConstraint := provider.MatchConstraints(constraintTags)
+	if ok == false {
+		if failingConstraint != nil {
+			log.Debugf("Container %v pruned by '%v' constraint", container.Name, failingConstraint.String())
+		}
+		return false
+	}
+
 	return true
 }
 
diff --git a/provider/docker_test.go b/provider/docker_test.go
index 3605d280a..364f0e885 100644
--- a/provider/docker_test.go
+++ b/provider/docker_test.go
@@ -621,6 +621,7 @@ func TestDockerGetLabels(t *testing.T) {
 }
 
 func TestDockerTraefikFilter(t *testing.T) {
+	provider := Docker{}
 	containers := []struct {
 		container docker.ContainerJSON
 		expected  bool
@@ -792,7 +793,7 @@ func TestDockerTraefikFilter(t *testing.T) {
 	}
 
 	for _, e := range containers {
-		actual := containerFilter(e.container)
+		actual := provider.ContainerFilter(e.container)
 		if actual != e.expected {
 			t.Fatalf("expected %v for %+v, got %+v", e.expected, e, actual)
 		}

From 357150bcab5c3b341ce5e238444d76d29cbf9f3e Mon Sep 17 00:00:00 2001
From: Samuel BERTHE <contact@samuel-berthe.fr>
Date: Sat, 11 Jun 2016 19:05:54 +0200
Subject: [PATCH 2/2] fix(constainrs,docker): Syntax

---
 provider/docker.go | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/provider/docker.go b/provider/docker.go
index 2afeb37c4..d2014b6df 100644
--- a/provider/docker.go
+++ b/provider/docker.go
@@ -220,8 +220,7 @@ func (provider *Docker) ContainerFilter(container dockertypes.ContainerJSON) boo
 	}
 
 	constraintTags := strings.Split(container.Config.Labels["traefik.tags"], ",")
-	ok, failingConstraint := provider.MatchConstraints(constraintTags)
-	if ok == false {
+	if ok, failingConstraint := provider.MatchConstraints(constraintTags); !ok {
 		if failingConstraint != nil {
 			log.Debugf("Container %v pruned by '%v' constraint", container.Name, failingConstraint.String())
 		}