Support clusters with nondefault cluster DNS names

README.md

@@ -24,7 +24,7 @@ Unlike the default `configurable-http-proxy` that ships with Jupyterhub, the tra
 
 The proxy can be deployed to a Kubernetes namespace running Jupyterhub by applying the following config:
 Change SUB_DOMAIN_HOST to a value to a hostname where jupyterhub is hosted. The ISTIO_GATEWAY value should be set to
-the gateway which handles traffic for jupyterhub.
+the gateway which handles traffic for jupyterhub. If your cluster has a non-default domain, you can specify that with CLUSTER_DOMAIN
 
 ```yaml
 apiVersion: apps/v1
@@ -83,6 +83,8 @@ spec:
               value: jupyterhub
             - name: WAIT_FOR_WARMUP
               value: "true"
+            - name: CLUSTER_DOMAIN
+              value: "cluster.local"
           image: splunk/jupyterhub-istio-proxy:0.0.2
           imagePullPolicy: IfNotPresent
           name: proxy

main.go

@@ -35,6 +35,7 @@ var gateway string
 var namespace string
 var waitForWarmup bool
 var vsNamePrefix string
+var clusterDomain string
 
 const (
 	gatewayEnvKey               = "ISTIO_GATEWAY"
@@ -44,6 +45,8 @@ const (
 	waitForWarmupKey            = "WAIT_FOR_WARMUP"
 	virtualServicePrefixKey     = "VIRTUAL_SERVICE_PREFIX"
 	virtualServicePrefixDefault = "jupyter"
+	clusterDomainEnvKey         = "CLUSTER_DOMAIN"
+	clusterDomainDefault        = "cluster.local"
 )
 
 func main() {
@@ -76,8 +79,11 @@ func main() {
 	if vsNamePrefix, ok = os.LookupEnv(virtualServicePrefixKey); !ok || vsNamePrefix == "" {
 		vsNamePrefix = virtualServicePrefixDefault
 	}
+	if clusterDomain, ok = os.LookupEnv(clusterDomainEnvKey); !ok || clusterDomain == "" {
+		clusterDomain = clusterDomainDefault
+	}
 	var ic proxy.Istioer
-	ic, err = proxy.NewIstioClient(namespace, gateway, subDomainHost, waitForWarmup, vsNamePrefix)
+	ic, err = proxy.NewIstioClient(namespace, gateway, subDomainHost, waitForWarmup, vsNamePrefix, clusterDomain)
 	if err != nil {
 		log.Fatalf("failed to create istio client: %s\n", err)
 	}

proxy/create.go

@@ -43,7 +43,7 @@ func (i *IstioClient) createVirtualService(r route) error {
 		return err
 	}
 	destinationHost, destinationPort := r.splitTarget()
-	destinationHost = fmt.Sprintf("%s.%s.svc.cluster.local", destinationHost, i.namespace)
+	destinationHost = fmt.Sprintf("%s.%s.svc.%s", destinationHost, i.namespace, i.clusterDomain)
 	vsName := i.virtualServiceNameWithPrefix(r.RouteSpec)
 	vs := virtualService(vsName, i.gateway, i.host, destinationHost, destinationPort, r.RouteSpec, annotations)
 

proxy/istio.go

@@ -39,10 +39,11 @@ type IstioClient struct {
 	namespace     string
 	waitForWarmup bool
 	vsNamePrefix  string
+	clusterDomain string
 }
 
 // NewIstioClient returns a new IstioClient
-func NewIstioClient(namespace string, gateway string, host string, waitForWarmup bool, vsNamePrefix string) (*IstioClient, error) {
+func NewIstioClient(namespace string, gateway string, host string, waitForWarmup bool, vsNamePrefix string, clusterDomain string) (*IstioClient, error) {
 	// creates the in-cluster config
 	config, err := rest.InClusterConfig()
 	if err != nil {
@@ -52,7 +53,7 @@ func NewIstioClient(namespace string, gateway string, host string, waitForWarmup
 	if err != nil {
 		return nil, err
 	}
-	return &IstioClient{Clientset: ic, namespace: namespace, gateway: gateway, host: host, waitForWarmup: waitForWarmup, vsNamePrefix: vsNamePrefix}, nil
+	return &IstioClient{Clientset: ic, namespace: namespace, gateway: gateway, host: host, waitForWarmup: waitForWarmup, vsNamePrefix: vsNamePrefix, clusterDomain: clusterDomain}, nil
 }
 func (c IstioClient) virtualServiceAnnotationNameWithPrefix() string {
 	return fmt.Sprintf("%s.splunk.io/proxy-data", c.virtualServicePrefix())