Marathon constraints filtering

docs/configuration/backends/marathon.md

@@ -68,6 +68,16 @@ domain = "marathon.localhost"
 #
 # marathonLBCompatibility = true
 
+# Enable filtering using Marathon constraints..
+# If enabled, Traefik will read Marathon constraints, as defined in https://mesosphere.github.io/marathon/docs/constraints.html
+# Each individual constraint will be treated as a verbatim compounded tag. 
+# i.e. "rack_id:CLUSTER:rack-1", with all constraint groups concatenated together using ":"
+#
+# Optional
+# Default: false
+#
+# filterMarathonConstraints = true
+
 # Enable Marathon basic authentication.
 #
 # Optional

provider/marathon/builder_test.go

@@ -44,6 +44,12 @@ func label(key, value string) func(*marathon.Application) {
 	}
 }
 
+func constraint(value string) func(*marathon.Application) {
+	return func(app *marathon.Application) {
+		app.AddConstraint(strings.Split(value, ":")...)
+	}
+}
+
 func labelWithService(key, value string, serviceName string) func(*marathon.Application) {
 	if len(serviceName) == 0 {
 		panic("serviceName can not be empty")

provider/marathon/marathon.go

@@ -59,6 +59,7 @@ type Provider struct {
 	GroupsAsSubDomains        bool             `description:"Convert Marathon groups to subdomains" export:"true"`
 	DCOSToken                 string           `description:"DCOSToken for DCOS environment, This will override the Authorization header" export:"true"`
 	MarathonLBCompatibility   bool             `description:"Add compatibility with marathon-lb labels" export:"true"`
+	FilterMarathonConstraints bool             `description:"Enable use of Marathon constraints in constraint filtering" export:"true"`
 	TLS                       *types.ClientTLS `description:"Enable Docker TLS support" export:"true"`
 	DialerTimeout             flaeg.Duration   `description:"Set a non-default connection timeout for Marathon" export:"true"`
 	KeepAlive                 flaeg.Duration   `description:"Set a non-default TCP Keep Alive time in seconds" export:"true"`
@@ -247,6 +248,11 @@ func (p *Provider) applicationFilter(app marathon.Application) bool {
 			constraintTags = append(constraintTags, label)
 		}
 	}
+	if p.FilterMarathonConstraints && app.Constraints != nil {
+		for _, constraintParts := range *app.Constraints {
+			constraintTags = append(constraintTags, strings.Join(constraintParts, ":"))
+		}
+	}
 	if ok, failingConstraint := p.MatchConstraints(constraintTags); !ok {
 		if failingConstraint != nil {
 			log.Debugf("Filtering Marathon application %v pruned by '%v' constraint", app.ID, failingConstraint.String())

provider/marathon/marathon_test.go

@@ -522,6 +522,7 @@ func TestMarathonApplicationFilterConstraints(t *testing.T) {
 		desc                      string
 		application               marathon.Application
 		marathonLBCompatibility   bool
+		filterMarathonConstraints bool
 		expected                  bool
 	}{
 		{
@@ -536,6 +537,27 @@ func TestMarathonApplicationFilterConstraints(t *testing.T) {
 			marathonLBCompatibility: false,
 			expected:                true,
 		},
+		{
+			desc:                      "constraint missing",
+			application:               application(),
+			marathonLBCompatibility:   false,
+			filterMarathonConstraints: true,
+			expected:                  false,
+		},
+		{
+			desc:                      "constraint invalid",
+			application:               application(constraint("service_cluster:CLUSTER:test")),
+			marathonLBCompatibility:   false,
+			filterMarathonConstraints: true,
+			expected:                  false,
+		},
+		{
+			desc:                      "constraint valid",
+			application:               application(constraint("valid")),
+			marathonLBCompatibility:   false,
+			filterMarathonConstraints: true,
+			expected:                  true,
+		},
 		{
 			desc: "LB compatibility tag matching",
 			application: application(
@@ -554,6 +576,7 @@ func TestMarathonApplicationFilterConstraints(t *testing.T) {
 			provider := &Provider{
 				ExposedByDefault:          true,
 				MarathonLBCompatibility:   c.marathonLBCompatibility,
+				FilterMarathonConstraints: c.filterMarathonConstraints,
 			}
 			constraint, err := types.NewConstraint("tag==valid")
 			if err != nil {