Merge pull request #171 from tayzlor/fix-170-marathon-getbackend

Fix #170 - getBackend for marathon plugin

docs/index.md

@@ -526,7 +526,7 @@ Labels can be used on containers to override default behaviour:
 - `traefik.weight=10`: assign this weight to the container
 - `traefik.enable=false`: disable this container in Træfɪk
 - `traefik.frontend.rule=Host`: override the default frontend rule (Default: Host). See [frontends](#frontends).
-- `traefik.frontend.value=test.example.com`: override the default frontend value (Default: `{containerName}.{domain}`) See [frontends](#frontends).
+- `traefik.frontend.value=test.example.com`: override the default frontend value (Default: `{containerName}.{domain}`) See [frontends](#frontends). Must be associated with label traefik.frontend.rule.
 - `traefik.frontend.passHostHeader=true`: forward client `Host` header to the backend.
 * `traefik.domain=traefik.localhost`: override the default domain
 
@@ -590,7 +590,7 @@ Labels can be used on containers to override default behaviour:
 - `traefik.weight=10`: assign this weight to the application
 - `traefik.enable=false`: disable this application in Træfɪk
 - `traefik.frontend.rule=Host`: override the default frontend rule (Default: Host). See [frontends](#frontends).
-- `traefik.frontend.value=test.example.com`: override the default frontend value (Default: `{appName}.{domain}`) See [frontends](#frontends).
+- `traefik.frontend.value=test.example.com`: override the default frontend value (Default: `{appName}.{domain}`) See [frontends](#frontends). Must be associated with label traefik.frontend.rule.
 - `traefik.frontend.passHostHeader=true`: forward client `Host` header to the backend.
 * `traefik.domain=traefik.localhost`: override the default domain
 
@@ -943,8 +943,8 @@ Percentage of the requests served within a certain time (ms)
 - Træfɪk:
 
 ```sh
-$ docker run -d -l traefik.backend=test1 -l traefik.host=test1 emilevauge/whoami
-$ docker run -d -l traefik.backend=test1 -l traefik.host=test1 emilevauge/whoami
+docker run -d -l traefik.backend=test1 -l traefik.frontend.rule=Host -l traefik.frontend.value=test1.docker.localhost emilevauge/whoami
+docker run -d -l traefik.backend=test1 -l traefik.frontend.rule=Host -l traefik.frontend.value=test1.docker.localhost emilevauge/whoami
 docker run -d -p 8080:8080 -p 80:80 -v $PWD/traefik.toml:/traefik.toml -v /var/run/docker.sock:/var/run/docker.sock emilevauge/traefik
 $ ab -n 20000 -c 20  -r http://test1.docker.localhost/
 This is ApacheBench, Version 2.3 <$Revision: 1528965 $>

provider/marathon.go

@@ -80,6 +80,7 @@ func (provider *Marathon) Provide(configurationChan chan<- types.ConfigMessage)
 
 func (provider *Marathon) loadMarathonConfig() *types.Configuration {
 	var MarathonFuncMap = template.FuncMap{
+		"getBackend":        provider.getBackend,
 		"getPort":           provider.getPort,
 		"getWeight":         provider.getWeight,
 		"getDomain":         provider.getDomain,
@@ -302,3 +303,10 @@ func (provider *Marathon) getFrontendRule(application marathon.Application) stri
 	}
 	return "Host"
 }
+
+func (provider *Marathon) getBackend(application marathon.Application) string {
+	if label, err := provider.getLabel(application, "traefik.backend"); err == nil {
+		return label
+	}
+	return replace("/", "-", application.ID)
+}

provider/marathon_test.go

@@ -800,3 +800,29 @@ func TestMarathonGetFrontendRule(t *testing.T) {
 		}
 	}
 }
+
+func TestMarathonGetBackend(t *testing.T) {
+	provider := &Marathon{}
+
+	applications := []struct {
+		application marathon.Application
+		expected    string
+	}{
+		{
+			application: marathon.Application{
+				ID: "foo",
+				Labels: map[string]string{
+					"traefik.backend": "bar",
+				},
+			},
+			expected: "bar",
+		},
+	}
+
+	for _, a := range applications {
+		actual := provider.getBackend(a.application)
+		if actual != a.expected {
+			t.Fatalf("expected %q, got %q", a.expected, actual)
+		}
+	}
+}

provider/provider.go

@@ -63,6 +63,7 @@ func replace(s1 string, s2 string, s3 string) string {
 	return strings.Replace(s3, s1, s2, -1)
 }
 
+// Escape beginning slash "/", convert all others to dash "-"
 func getEscapedName(name string) string {
-	return strings.Replace(name, "/", "", -1)
+	return strings.Replace(strings.TrimPrefix(name, "/"), "/", "-", -1)
 }

templates/marathon.tmpl

@@ -1,13 +1,13 @@
 {{$apps := .Applications}}
 [backends]{{range .Tasks}}
-    [backends.backend{{.AppID | replace "/" "-"}}.servers.server-{{.ID | replace "." "-"}}]
+    [backends.backend{{with index $apps 0 }}{{getBackend .}}{{end}}.servers.server-{{.ID | replace "." "-"}}]
     url = "{{getProtocol . $apps}}://{{.Host}}:{{getPort . $apps}}"
     weight = {{getWeight . $apps}}
 {{end}}
 
 [frontends]{{range .Applications}}
   [frontends.frontend{{.ID | replace "/" "-"}}]
-  backend = "backend{{.ID | replace "/" "-"}}"
+  backend = "backend{{getBackend .}}"
   passHostHeader = {{getPassHostHeader .}}
     [frontends.frontend{{.ID | replace "/" "-"}}.routes.route-host{{.ID | replace "/" "-"}}]
     rule = "{{getFrontendRule .}}"