E2E: implement tests for receiving prefixes

Here we implement e2e test to ensure frr-k8s is able to receive routes
from outside.

Signed-off-by: Federico Paolinelli <[email protected]>

e2etests/pkg/routes/routes.go

@@ -16,6 +16,19 @@ import (
 	"k8s.io/kubernetes/test/e2e/framework"
 )
 
+// PodHasPrefixFromContainer tells if the given frr-k8s pod has recevied a route for
+// the given prefix from the given container.
+func PodHasPrefixFromContainer(pod *v1.Pod, frr frrcontainer.FRR, prefix string) bool {
+	_, cidr, _ := net.ParseCIDR(prefix)
+	ipFamily := ipfamily.ForCIDR(cidr)
+	nextHop := frr.Ipv4
+	if ipFamily == ipfamily.IPv6 {
+		nextHop = frr.Ipv6
+	}
+	vrf := frr.RouterConfig.VRF
+	return havePrefix(pod, ipFamily, cidr, nextHop, vrf)
+}
+
 // CheckNeighborHasPrefix tells if the given frr container has a route toward the given prefix
 // via the set of node passed to this function.
 func CheckNeighborHasPrefix(neighbor frrcontainer.FRR, prefix string, nodes []v1.Node) (bool, error) {

e2etests/pkg/routes/routes.go.old

@@ -0,0 +1,105 @@
+// SPDX-License-Identifier:Apache-2.0
+
+package routes
+
+import (
+	"bytes"
+	"fmt"
+	"net"
+
+	"go.universe.tf/e2etest/pkg/frr"
+	frrcontainer "go.universe.tf/e2etest/pkg/frr/container"
+	"go.universe.tf/e2etest/pkg/ipfamily"
+	"go.universe.tf/metallb/e2etest/pkg/executor"
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/kubernetes/test/e2e/framework"
+)
+
+func PodHasPrefixFromContainer(pod *v1.Pod, frr frrcontainer.FRR, prefix string) bool {
+	_, cidr, _ := net.ParseCIDR(prefix)
+	ipFamily := ipfamily.ForCIDR(cidr)
+	nextHop := frr.Ipv4
+	if ipFamily == ipfamily.IPv6 {
+		nextHop = frr.Ipv6
+	}
+	vrf := frr.RouterConfig.VRF
+	return havePrefix(pod, ipFamily, cidr, nextHop, vrf)
+}
+
+// CheckNeighborHasPrefix tells if the given frr container has a route toward the given prefix
+// via the set of node passed to this function.
+func CheckNeighborHasPrefix(neighbor *frrcontainer.FRR, prefix string, nodes []v1.Node) error {
+	routesV4, routesV6, err := frr.Routes(neighbor)
+	if err != nil {
+		return err
+	}
+
+	_, cidr, err := net.ParseCIDR(prefix)
+	if err != nil {
+		return err
+	}
+
+	route, err := routeForCIDR(cidr, routesV4, routesV6)
+	if err != nil {
+		return err
+	}
+
+	cidrFamily := ipfamily.ForCIDR(cidr)
+	err = frr.RoutesMatchNodes(nodes, route, cidrFamily, neighbor.RouterConfig.VRF)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func cidrsAreEqual(a, b *net.IPNet) bool {
+	return a.IP.Equal(b.IP) && bytes.Equal(a.Mask, b.Mask)
+}
+
+type RouteNotFoundError string
+
+func (e RouteNotFoundError) Error() string {
+	return string(e)
+}
+
+func routeForCIDR(cidr *net.IPNet, routesV4 map[string]frr.Route, routesV6 map[string]frr.Route) (frr.Route, error) {
+	for _, route := range routesV4 {
+		if cidrsAreEqual(route.Destination, cidr) {
+			return route, nil
+		}
+	}
+	for _, route := range routesV6 {
+		if cidrsAreEqual(route.Destination, cidr) {
+			return route, nil
+		}
+	}
+	return frr.Route{}, RouteNotFoundError(fmt.Sprintf("route %s not found", cidr))
+}
+
+func havePrefix(pod *v1.Pod, pairingFamily ipfamily.Family, prefix *net.IPNet, nextHop, vrf string) bool {
+	found := false
+	podExec := executor.ForPod(pod.Namespace, pod.Name, "frr")
+	routes, frrRoutesV6, err := frr.RoutesForVRF(vrf, podExec)
+	framework.ExpectNoError(err)
+
+	if pairingFamily == ipfamily.IPv6 {
+		routes = frrRoutesV6
+	}
+
+out:
+	for _, route := range routes {
+		if !cidrsAreEqual(route.Destination, prefix) {
+			continue
+		}
+		for _, nh := range route.NextHops {
+			if nh.String() == nextHop {
+				found = true
+				break out
+			}
+		}
+	}
+	if !found {
+		return false
+	}
+	return true
+}