Configure routing subdomain

* pkg/operator/observe_config.go (Listers): Add new lister installConfigLister.
(NewConfigObserver): Add installConfigLister to listers, and add
observeRoutingSubdomain to observers.
(observeRoutingSubdomain): Add new observer to set routingConfig.Subdomain
from the install config.
* pkg/operator/operator.go: Add constants clusterConfigNamespace and
clusterConfigName.

This commit resolves NE-100.

https://jira.coreos.com/browse/NE-100

pkg/operator/observe_config.go

@@ -7,6 +7,8 @@ import (
 	"reflect"
 	"time"
 
+	"github.com/ghodss/yaml"
+
 	"github.com/golang/glog"
 
 	corev1 "k8s.io/api/core/v1"
@@ -30,9 +32,10 @@ import (
 )
 
 type Listers struct {
-	imageConfigLister configlistersv1.ImageLister
-	endpointLister    corelistersv1.EndpointsLister
-	configmapLister   corelistersv1.ConfigMapLister
+	imageConfigLister   configlistersv1.ImageLister
+	endpointLister      corelistersv1.EndpointsLister
+	configmapLister     corelistersv1.ConfigMapLister
+	installConfigLister corelistersv1.ConfigMapLister
 }
 
 type observeConfigFunc func(Listers, map[string]interface{}) (map[string]interface{}, error)
@@ -71,11 +74,13 @@ func NewConfigObserver(
 			observeKubeAPIServerPublicInfo,
 			observeEtcdEndpoints,
 			observeInternalRegistryHostname,
+			observeRoutingSubdomain,
 		},
 		listers: Listers{
-			imageConfigLister: imageConfigInformer.Config().V1().Images().Lister(),
-			endpointLister:    kubeInformersForKubeSystemNamespace.Core().V1().Endpoints().Lister(),
-			configmapLister:   kubeInformersForKubeApiserverNamespace.Core().V1().ConfigMaps().Lister(),
+			imageConfigLister:   imageConfigInformer.Config().V1().Images().Lister(),
+			endpointLister:      kubeInformersForKubeSystemNamespace.Core().V1().Endpoints().Lister(),
+			installConfigLister: kubeInformersForKubeSystemNamespace.Core().V1().ConfigMaps().Lister(),
+			configmapLister:     kubeInformersForKubeApiserverNamespace.Core().V1().ConfigMaps().Lister(),
 		},
 	}
 
@@ -179,6 +184,40 @@ func observeInternalRegistryHostname(listers Listers, observedConfig map[string]
 	return observedConfig, nil
 }
 
+func observeRoutingSubdomain(listers Listers, observedConfig map[string]interface{}) (map[string]interface{}, error) {
+	clusterConfig, err := listers.installConfigLister.ConfigMaps(clusterConfigNamespace).Get(clusterConfigName)
+	if errors.IsNotFound(err) {
+		return observedConfig, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	if clusterConfig != nil {
+		if installConfig, ok := clusterConfig.Data["install-config"]; ok {
+			type InstallConfigMetadata struct {
+				Name string `json:"name"`
+			}
+
+			type InstallConfig struct {
+				Metadata   InstallConfigMetadata `json:"metadata"`
+				BaseDomain string                `json:"baseDomain"`
+			}
+
+			var config InstallConfig
+			if err := yaml.Unmarshal([]byte(installConfig), &config); err != nil {
+				return nil, fmt.Errorf("invalid InstallConfig: %v\njson:\n%s", err, installConfig)
+			}
+
+			subdomain := fmt.Sprintf("%s.%s", config.Metadata.Name, config.BaseDomain)
+
+			unstructured.SetNestedField(observedConfig, subdomain, "routingConfig", "subdomain")
+		}
+	}
+
+	return observedConfig, nil
+}
+
 func (c *ConfigObserver) Run(workers int, stopCh <-chan struct{}) {
 	defer utilruntime.HandleCrash()
 	defer c.queue.ShutDown()

pkg/operator/operator.go

@@ -30,6 +30,8 @@ import (
 )
 
 const (
+	clusterConfigNamespace     = "kube-system"
+	clusterConfigName          = "cluster-config-v1"
 	etcdNamespaceName          = "kube-system"
 	kubeAPIServerNamespaceName = "openshift-kube-apiserver"
 	targetNamespaceName        = "openshift-apiserver"