Add support for the IPALLOC_DEFAULT_SUBNET environment variable to the launch.sh script

prog/weave-kube/launch.sh

@@ -38,6 +38,7 @@ setup_iptables_backend
 
 # Default if not supplied - same as weave net default
 IPALLOC_RANGE=${IPALLOC_RANGE:-10.32.0.0/12}
+IPALLOC_DEFAULT_SUBNET=${IPALLOC_DEFAULT_SUBNET:-${IPALLOC_RANGE}}
 HTTP_ADDR=${WEAVE_HTTP_ADDR:-127.0.0.1:6784}
 METRICS_ADDR=${WEAVE_METRICS_ADDR:-0.0.0.0:6782}
 HOST_ROOT=${HOST_ROOT:-/host}
@@ -149,6 +150,7 @@ post_start_actions &
      --db-prefix="$DB_PREFIX" \
      --ipalloc-range=$IPALLOC_RANGE $NICKNAME_ARG \
      --ipalloc-init $IPALLOC_INIT \
+     --ipalloc-default-subnet=$IPALLOC_DEFAULT_SUBNET
      --conn-limit=$CONN_LIMIT \
      $WEAVE_NPC_OPTS \
      $NO_MASQ_LOCAL_OPT \

site/kubernetes/kube-addon.md

@@ -447,6 +447,8 @@ The list of variables you can set is:
   by setting `HAIRPIN_MODE=false`.
 * `IPALLOC_RANGE` - the range of IP addresses used by Weave Net
   and the subnet they are placed in (CIDR format; default `10.32.0.0/12`)
+* `IPALLOC_DEFAULT_SUBNET` - a subnet of IPALLOC_RANGE from which IP addresses
+  are automatically assigned (CIDR format; default to value of IPALLOC_RANGE).
 * `EXPECT_NPC` - set to 0 to disable Network Policy Controller (default is on)
 * `KUBE_PEERS` - list of addresses of peers in the Kubernetes cluster
   (default is to fetch the list from the api-server)