Merge pull request flannel-io#1582 from rbrtbnfgl/etcd-subnetv6

Fixed subnet allocation in case of etcd manager with IPv6

dist/functional-test.sh

@@ -59,9 +59,10 @@ write_config_etcd() {
         flannel_conf="{ \"Network\": \"$FLANNEL_NET\", \"Backend\": { \"Type\": \"${backend}\" } }"
     fi
 
-    while ! docker run --rm -e ETCDCTL_API=3 $ETCDCTL_IMG etcdctl --endpoints=$etcd_endpt put /coreos.com/network/config "$flannel_conf" >/dev/null
+    while ! docker run --rm -e ETCDCTL_API=3 $ETCDCTL_IMG etcdctl --endpoints=$etcd_endpt put /coreos.com/network/config "$flannel_conf"
     do
         sleep 0.1
+	echo "Retrying write_config_etcd with backend $1"
     done
 }
 
@@ -70,6 +71,7 @@ create_ping_dest() {
     for host_num in 1 2; do
        while ! docker exec flannel-e2e-test-flannel$host_num ls /run/flannel/subnet.env >/dev/null 2>&1; do
          sleep 0.1
+	 echo "Retrying create_ping_dest() with host_num=$host_num"
        done
 
        # Use declare to allow the host_num variable to be part of the ping_dest variable name. -g is needed to make it global
@@ -133,8 +135,11 @@ pings() {
 
 # These perf tests don't actually assert on anything
 test_hostgw_perf() {
+    echo "Inside test_hostgw_perf()"
     write_config_etcd host-gw
+    echo "In test_hostgw_perf(). write_config_etcd done!"
     create_ping_dest
+    echo "In test_hostgw_perf(). Create_ping_dest done!"
     perf
 }
 
@@ -172,9 +177,12 @@ test_wireguard_perf() {
 
 perf() {
     # Perf test - run iperf server on flannel1 and client on flannel2
-    docker rm -f flannel-e2e-test-flannel1-iperf 2>/dev/null
-    docker run -d --name flannel-e2e-test-flannel1-iperf --net=container:flannel-e2e-test-flannel1 iperf3:latest >/dev/null
+    docker rm -f flannel-e2e-test-flannel1-iperf
+    echo "Inside perf(). docker rm done"
+    docker run -d --name flannel-e2e-test-flannel1-iperf --net=container:flannel-e2e-test-flannel1 iperf3:latest
+    echo "Inside perf(). docker run -d done"
     docker run --rm --net=container:flannel-e2e-test-flannel2 iperf3:latest -c $ping_dest1 -B $ping_dest2
+    echo "Inside perf(). docker run -rm done"
 }
 
 test_multi() {

main.go

@@ -628,3 +628,4 @@ func ReadIP6CIDRFromSubnetFile(path string, CIDRKey string) ip.IP6Net {
 	}
 	return prevCIDR
 }
+

subnet/etcd/local_manager.go

@@ -202,11 +202,8 @@ func (m *LocalManager) allocateSubnet(config *Config, leases []Lease) (ip.IP4Net
 		log.Infof("Picking ipv6 subnet in range %s ... %s", config.IPv6SubnetMin, config.IPv6SubnetMax)
 	}
 
-	type IPs struct {
-		ip  ip.IP4
-		ip6 *ip.IP6
-	}
-	var availableIPs []IPs
+	var availableIPs []ip.IP4
+	var availableIPv6s []*ip.IP6
 
 	sn := ip.IP4Net{IP: config.SubnetMin, PrefixLen: config.SubnetLen}
 	var sn6 ip.IP6Net
@@ -216,38 +213,37 @@ func (m *LocalManager) allocateSubnet(config *Config, leases []Lease) (ip.IP4Net
 
 OuterLoop:
 	for ; sn.IP <= config.SubnetMax && len(availableIPs) < 100; sn = sn.Next() {
-		if !sn6.Empty() {
-			if sn6.IP.Cmp(config.IPv6SubnetMax) >= 0 {
-				break OuterLoop
-			}
-		}
 		for _, l := range leases {
 			if sn.Overlaps(l.Subnet) {
 				continue OuterLoop
 			}
-			if !sn6.Empty() && sn6.Overlaps(l.IPv6Subnet) {
-				continue OuterLoop
-			}
 		}
+		availableIPs = append(availableIPs, sn.IP)
+	}
 
-		if !sn6.Empty() {
-			availableIPs = append(availableIPs, IPs{ip: sn.IP, ip6: sn6.IP})
-			sn6 = sn6.Next()
-		} else {
-			availableIPs = append(availableIPs, IPs{ip: sn.IP, ip6: nil})
+	if !sn6.Empty() {
+	OuterLoopv6:
+		for ; sn6.IP.Cmp(config.IPv6SubnetMax) <= 0 && len(availableIPv6s) < 100; sn6 = sn6.Next() {
+			for _, l := range leases {
+				if sn6.Overlaps(l.IPv6Subnet) {
+					continue OuterLoopv6
+				}
+			}
+			availableIPv6s = append(availableIPv6s, sn6.IP)
 		}
 	}
 
-	if len(availableIPs) == 0 {
+	if len(availableIPs) == 0 || (!sn6.Empty() && len(availableIPv6s) == 0) {
 		return ip.IP4Net{}, ip.IP6Net{}, errors.New("out of subnets")
 	} else {
 		i := randInt(0, len(availableIPs))
-		ipnet := ip.IP4Net{IP: availableIPs[i].ip, PrefixLen: config.SubnetLen}
+		ipnet := ip.IP4Net{IP: availableIPs[i], PrefixLen: config.SubnetLen}
 
-		if availableIPs[i].ip6 == nil {
+		if sn6.Empty() {
 			return ipnet, ip.IP6Net{}, nil
 		}
-		return ipnet, ip.IP6Net{IP: availableIPs[i].ip6, PrefixLen: config.IPv6SubnetLen}, nil
+		i = randInt(0, len(availableIPv6s))
+		return ipnet, ip.IP6Net{IP: availableIPv6s[i], PrefixLen: config.IPv6SubnetLen}, nil
 	}
 }