Default values for FISSION_* env vars (#518)

This makes set up easier for new users.  Users can still set
FISSION_NAMESPACE but it will default to "fission".  Users can also
still set KUBECONFIG, but it will default to $HOME/.kube/config.

Also, update the post-install chart notes.txt and the install guide to
use "fission function test" as the first step after install.  This
means that if there's anything wrong with the setup, the user will see
useful errors instead of "internal server error".  Also, they can test
their setup without worrying about nodeports or ingresses or whatever.

All existing functionality of FISSION_URL and FISSION_ROUTER continues
to work.

fission/portforward.go

@@ -8,10 +8,11 @@ import (
 	"time"
 
 	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	//	"k8s.io/client-go/rest"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/clientcmd"
 	"k8s.io/client-go/tools/portforward"
 	"k8s.io/client-go/tools/remotecommand"
-
-	"github.com/fission/fission/crd"
 )
 
 func findFreePort() (string, error) {
@@ -39,28 +40,38 @@ func findFreePort() (string, error) {
 	return port, nil
 }
 
-func runportForward(serviceName string, localPort string, fissionNamespace string) error {
-	//KUBECONFIG needs to be set to the correct path i.e ~/.kube/config
-	config, podClient, _, err := crd.GetKubernetesClient()
+// runPortForward creates a local port forward to the specified pod
+func runPortForward(kubeConfig string, labelSelector string, localPort string, fissionNamespace string) error {
+	config, err := clientcmd.BuildConfigFromFlags("", kubeConfig)
 	if err != nil {
-		fatal(err.Error())
+		fatal(fmt.Sprintf("Failed to connect to Kubernetes: %s", err))
 	}
 
-	//get the podname for the controller
-	podList, err := podClient.CoreV1().Pods(fissionNamespace).List(meta_v1.ListOptions{LabelSelector: "application=fission-api"})
+	clientset, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		fatal(fmt.Sprintf("Failed to connect to Kubernetes: %s", err))
+	}
+
+	// get the pod; if there is more than one, always port-forward to the first.
+	podList, err := clientset.CoreV1().Pods(fissionNamespace).
+		List(meta_v1.ListOptions{LabelSelector: labelSelector})
 	if err != nil || len(podList.Items) == 0 {
 		fatal("Error getting controller pod for port-forwarding")
 	}
 
-	// if there are more than one pods, always port-forward to the first pod returned
 	podName := podList.Items[0].Name
 	podNameSpace := podList.Items[0].Namespace
 
-	//get the ControllerPort
-	service, err := podClient.CoreV1().Services(podNameSpace).Get(serviceName, meta_v1.GetOptions{})
+	// get the service and the target port
+	svcs, err := clientset.CoreV1().Services(podNameSpace).
+		List(meta_v1.ListOptions{LabelSelector: labelSelector})
 	if err != nil {
-		fatal(fmt.Sprintf("Error getting %v service :%v", serviceName, err.Error()))
+		fatal(fmt.Sprintf("Error getting %v service :%v", labelSelector, err.Error()))
 	}
+	if len(svcs.Items) == 0 {
+		fatal(fmt.Sprintf("Service %v not found", labelSelector))
+	}
+	service := &svcs.Items[0]
 
 	var targetPort string
 	for _, servicePort := range service.Spec.Ports {
@@ -70,15 +81,16 @@ func runportForward(serviceName string, localPort string, fissionNamespace strin
 	stopChannel := make(chan struct{}, 1)
 	readyChannel := make(chan struct{})
 
-	//create request URL
-	req := podClient.CoreV1Client.RESTClient().Post().Resource("pods").Namespace(podNameSpace).Name(podName).SubResource("portforward")
+	// create request URL
+	req := clientset.CoreV1Client.RESTClient().Post().Resource("pods").
+		Namespace(podNameSpace).Name(podName).SubResource("portforward")
 	url := req.URL()
 
-	//create ports slice
+	// create ports slice
 	portCombo := localPort + ":" + targetPort
 	ports := []string{portCombo}
 
-	//actually start the port-forwarding process here
+	// actually start the port-forwarding process here
 	dialer, err := remotecommand.NewExecutor(config, "POST", url)
 	if err != nil {
 		msg := fmt.Sprintf("newexecutor errored out :%v", err.Error())
@@ -94,15 +106,20 @@ func runportForward(serviceName string, localPort string, fissionNamespace strin
 	return fw.ForwardPorts()
 }
 
-func controllerPodPortForward(fissionNamespace string) string {
-	localControllerPort, err := findFreePort()
+// Port forward a free local port to a pod on the cluster. The pod is
+// found in the specified namespace by labelSelector. The pod's port
+// is found by looking for a service in the same namespace and using
+// its targetPort. Once the port forward is started, wait for it to
+// start accepting connections before returning.
+func setupPortForward(kubeConfig, namespace, labelSelector string) string {
+	localPort, err := findFreePort()
 	if err != nil {
 		fatal(fmt.Sprintf("Error finding unused port :%v", err.Error()))
 	}
 
-	timeBefore := time.Now()
 	for {
-		conn, _ := net.DialTimeout("tcp", net.JoinHostPort("", localControllerPort), time.Millisecond)
+		conn, _ := net.DialTimeout("tcp",
+			net.JoinHostPort("", localPort), time.Millisecond)
 		if conn != nil {
 			conn.Close()
 		} else {
@@ -111,20 +128,16 @@ func controllerPodPortForward(fissionNamespace string) string {
 		time.Sleep(time.Millisecond * 50)
 	}
 
-	timeAfter := time.Since(timeBefore)
-	if timeAfter.Seconds()/1000 >= 100 {
-		fatal(fmt.Sprintln("Lag in connecting to a free port on the localhost"))
-	}
-
 	go func() {
-		err := runportForward("controller", localControllerPort, fissionNamespace)
+		err := runPortForward(kubeConfig, labelSelector, localPort, namespace)
 		if err != nil {
-			fatal(err.Error())
+			fatal(fmt.Sprintf("Error forwarding to controller port: %s", err.Error()))
 		}
 	}()
 
 	for {
-		conn, _ := net.DialTimeout("tcp", net.JoinHostPort("", localControllerPort), time.Millisecond)
+		conn, _ := net.DialTimeout("tcp",
+			net.JoinHostPort("", localPort), time.Millisecond)
 		if conn != nil {
 			conn.Close()
 			break
@@ -132,5 +145,5 @@ func controllerPodPortForward(fissionNamespace string) string {
 		time.Sleep(time.Millisecond * 50)
 	}
 
-	return localControllerPort
+	return localPort
 }