Fix IPv6 enabled devstack and namespace subnet plugin.

In case of setting subnet driver to 'namespace', and making use of IPv6
in kuryr devstack‚ we experienced a clash with devstack route, since we
used to use shared subnet pool crated by devstack.

To avoid such clash, for IPv6 we simply create our own IPv6 shared
subnet pool, and subnets within it.

Change-Id: Iad40167d28078b2d6811d3afed58b8da4b41cd42

devstack/lib/kuryr_kubernetes

@@ -76,7 +76,7 @@ function ovs_bind_for_kubelet() {
         if [ "$KURYR_IPV6" == "False" ]; then
             subnetpool_id=${KURYR_NEUTRON_DEFAULT_SUBNETPOOL_ID:-${SUBNETPOOL_V4_ID}}
         else
-            subnetpool_id=${KURYR_NEUTRON_DEFAULT_SUBNETPOOL_ID:-${SUBNETPOOL_V6_ID}}
+            subnetpool_id=${KURYR_NEUTRON_DEFAULT_SUBNETPOOL_ID:-${SUBNETPOOL_KURYR_V6_ID}}
         fi
         cidrs=$(openstack subnet pool show "${subnetpool_id}" -c prefixes -f value)
         subnetpool_cidr=$(python3 -c "print(${cidrs}[0])")

devstack/plugin.sh

@@ -274,8 +274,8 @@ function configure_neutron_defaults {
     local router
     local router_id
     local ext_svc_net_id
-    local ext_svc_subnet_id
-    local prot
+    local addrs_prefix
+    local subnetpool_name
 
     project_id=$(get_or_create_project \
         "$KURYR_NEUTRON_DEFAULT_PROJECT" default)
@@ -290,7 +290,27 @@ function configure_neutron_defaults {
         subnetpool_id=${KURYR_NEUTRON_DEFAULT_SUBNETPOOL_ID:-${SUBNETPOOL_V4_ID}}
     else
         export KURYR_ETHERTYPE=IPv6
-      subnetpool_id=${KURYR_NEUTRON_DEFAULT_SUBNETPOOL_ID:-${SUBNETPOOL_V6_ID}}
+        # NOTE(gryf): To not clash with subnets created by DevStack for IPv6,
+        # we create another subnetpool just for kuryr subnets.
+        # SUBNETPOOL_KURYR_V6_ID will be used in function configure_kuryr in
+        # case of namespace kuryr subnet driver.
+        # This is not required for IPv4, because DevStack is only adding a
+        # conflicting route for IPv6. On DevStack this route is opening public
+        # IPv6 network to be accessible from host, which doesn't have place in
+        # IPv4 net, because floating IPs are used instead.
+        IPV6_ID=$(uuidgen | sed s/-//g | cut -c 23- | \
+            sed -e "s/\(..\)\(....\)\(....\)/\1:\2:\3/")
+        addrs_prefix="fd${IPV6_ID}::/56"
+        subnetpool_name=${SUBNETPOOL_KURYR_NAME_V6}
+        SUBNETPOOL_KURYR_V6_ID=$(openstack \
+            --os-cloud devstack-admin \
+            --os-region "${REGION_NAME}" \
+            subnet pool create "${subnetpool_name}" \
+            --default-prefix-length "${SUBNETPOOL_SIZE_V6}" \
+            --pool-prefix "${addrs_prefix}" \
+            --share -f value -c id)
+        export SUBNETPOOL_KURYR_V6_ID
+        subnetpool_id=${KURYR_NEUTRON_DEFAULT_SUBNETPOOL_ID:-${SUBNETPOOL_KURYR_V6_ID}}
     fi
 
     router=${KURYR_NEUTRON_DEFAULT_ROUTER:-$Q_ROUTER_NAME}

devstack/settings

@@ -104,3 +104,4 @@ KURYR_CONTAINERS_USE_LOWER_CONSTRAINTS=${KURYR_CONTAINERS_USE_LOWER_CONSTRAINTS:
 KURYR_OVERCLOUD_VM_PORT=${KURYR_OVERCLOUD_VM_PORT:-port0}
 
 KURYR_IPV6=${KURYR_IPV6:-False}
+SUBNETPOOL_KURYR_NAME_V6=${SUBNETPOOL_KURYR_NAME_V6:-"shared-kuryr-subnetpool-v6"}