routesrv: require kubernetes option

Require kubernetes option (explicitly or via -kubernetes flag).

Initially routesrv implied this option as it was envisioned for serving
Kubernetes dataclient routes.

Later an endpoint to serve Redis endpoints was added by #2237

Within #2476 skipper allows Redis endpoints discovery without using
kubernetes dataclient for routing.
This behaviour is configured by the -kubernetes flag.

The plan is to allow routesrv the same - provide Redis endpoints without
using Kubernetes dataclient to create routes.

This change is the first step that converts implied Kubernetes option
into required.

This is a breaking change for users that run routesrv without
-kubernetes flag or use it from the library without setting Kubernetes
option.

For #2476

Signed-off-by: Alexander Yastrebov <alexander.yastrebov@zalando.de>

VERSION

@@ -1 +1 @@
-v0.20
+v0.21

redis_test.go

@@ -136,6 +136,7 @@ spec:
 
 	rsvo := skipper.Options{
 		Address:                         findAddress(t),
+		Kubernetes:                      true,
 		KubernetesURL:                   lb.URL,
 		KubernetesRedisServiceNamespace: "skipper",
 		KubernetesRedisServiceName:      "redis",

routesrv/routesrv.go

@@ -2,6 +2,7 @@ package routesrv
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"os"
 	"os/signal"
@@ -85,6 +86,10 @@ func New(opts skipper.Options) (*RouteServer, error) {
 		supportHandler.Handle("/debug/pprof/", metricsHandler)
 	}
 
+	if !opts.Kubernetes {
+		return nil, fmt.Errorf("kubernetes option is required")
+	}
+
 	dataclient, err := kubernetes.New(opts.KubernetesDataClientOptions())
 	if err != nil {
 		return nil, err

routesrv/routesrv_test.go

@@ -72,6 +72,7 @@ func loadKubeYAML(t *testing.T, path string) io.Reader {
 func newRouteServer(t *testing.T, kubeServer *httptest.Server) *routesrv.RouteServer {
 	return newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout: pollInterval,
+		Kubernetes:        true,
 		KubernetesURL:     kubeServer.URL,
 	})
 }
@@ -249,6 +250,7 @@ func TestRedisEndpointSlices(t *testing.T) {
 		defer ks.Close()
 		rs := newRouteServerWithOptions(t, skipper.Options{
 			SourcePollTimeout:               pollInterval,
+			Kubernetes:                      true,
 			KubernetesURL:                   ks.URL,
 			KubernetesRedisServiceNamespace: "namespace1",
 			KubernetesRedisServiceName:      "service1",
@@ -272,6 +274,7 @@ func TestRedisEndpoints(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout:               pollInterval,
+		Kubernetes:                      true,
 		KubernetesURL:                   ks.URL,
 		KubernetesRedisServiceNamespace: "namespace1",
 		KubernetesRedisServiceName:      "service1",
@@ -293,6 +296,7 @@ func TestFetchedIngressRoutesAreServedInEskipFormat(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout: pollInterval,
+		Kubernetes:        true,
 		KubernetesURL:     ks.URL,
 	})
 
@@ -376,6 +380,7 @@ func TestRoutesWithDefaultFilters(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout: pollInterval,
+		Kubernetes:        true,
 		KubernetesURL:     ks.URL,
 		DefaultFilters: &eskip.DefaultFilters{
 			Prepend: []*eskip.Filter{
@@ -419,6 +424,7 @@ func TestRoutesWithOAuth2Callback(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout:     pollInterval,
+		Kubernetes:            true,
 		KubernetesURL:         ks.URL,
 		EnableOAuth2GrantFlow: true,
 		OAuth2CallbackPath:    "/.well-known/oauth2-callback",
@@ -450,6 +456,7 @@ func TestRoutesWithEastWest(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout:              pollInterval,
+		Kubernetes:                     true,
 		KubernetesURL:                  ks.URL,
 		KubernetesEastWestRangeDomains: []string{"ingress.cluster.local"},
 		KubernetesEastWestRangePredicates: []*eskip.Predicate{
@@ -610,6 +617,7 @@ func TestESkipBytesHandlerWithXCount(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout: pollInterval,
+		Kubernetes:        true,
 		KubernetesURL:     ks.URL,
 	})
 
@@ -642,6 +650,7 @@ func TestRoutesWithEditRoute(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout: pollInterval,
+		Kubernetes:        true,
 		KubernetesURL:     ks.URL,
 		EditRoute: []*eskip.Editor{
 			eskip.NewEditor(regexp.MustCompile("Host[(](.*)[)]"), "HostAny($1)"),
@@ -674,6 +683,7 @@ func TestRoutesWithCloneRoute(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout: pollInterval,
+		Kubernetes:        true,
 		KubernetesURL:     ks.URL,
 		CloneRoute: []*eskip.Clone{
 			eskip.NewClone(regexp.MustCompile("Host"), "HostAny"),
@@ -706,6 +716,7 @@ func TestRoutesWithExplicitLBAlgorithm(t *testing.T) {
 	defer ks.Close()
 	rs := newRouteServerWithOptions(t, skipper.Options{
 		SourcePollTimeout:                      pollInterval,
+		Kubernetes:                             true,
 		KubernetesURL:                          ks.URL,
 		KubernetesDefaultLoadBalancerAlgorithm: "powerOfRandomNChoices",
 	})
@@ -793,6 +804,7 @@ func TestESkipBytesHandlerGzipServedForDefaultClient(t *testing.T) {
 
 	rs, err := routesrv.New(skipper.Options{
 		SourcePollTimeout: pollInterval,
+		Kubernetes:        true,
 		KubernetesURL:     ks.URL,
 	})
 	require.NoError(t, err)

routesrv/shutdown_test.go

@@ -69,6 +69,7 @@ func TestServerShutdownHTTP(t *testing.T) {
 	ks.Start()
 
 	o := skipper.Options{
+		Kubernetes:        true,
 		KubernetesURL:     "http://" + ks.Listener.Addr().String(),
 		SourcePollTimeout: 500 * time.Millisecond,
 	}