make/cluster.sh: remove the fixed clusterIP CIDR 10.0.0.0

The fixed CIDR isn't necessary anymore since the makefile figures the
ClusterIP dynamically. This change also enables you to run
make/cluster.sh with an existing kind cluster.

Signed-off-by: Maël Valais <mael@vls.dev>

make/cluster.sh

@@ -176,9 +176,11 @@ setup_kind() {
     printf "and then retry.\n" >&2
   fi
 
+  service_ip_prefix=$(set +o pipefail && kubectl cluster-info dump | grep -m1 ip-range | cut -d= -f2 | cut -d. -f1,2,3)
+
   # (6) Has the Corefile been patched?
   corefile=$(kubectl get -ogo-template='{{.data.Corefile}}' -n=kube-system configmap/coredns)
-  to_be_appended=$'example.com:53 {\n    forward . 10.0.0.16\n}\n'
+  to_be_appended=$'example.com:53 {\n    forward . '$service_ip_prefix$'.16\n}\n'
   if ! grep -q --null-data -F "$(tr -d $'\n' <<<"$to_be_appended")" <(tr -d $'\n' <<<"$corefile"); then
     kubectl create configmap -oyaml coredns --dry-run=client --from-literal=Corefile="$(printf '%s\n%s' "$corefile" "$to_be_appended")" \
       | kubectl apply -n kube-system -f - >/dev/null

make/config/kind/v1beta2.yaml

@@ -1,8 +1,3 @@
-# this config file is similar to the default, except we set the cluster's
-# service cidr range to be 10.0.0.0/16.
-# we do this because we need a fixed/predictable clusterIP of 10.0.0.15 for the
-# nginx-ingress service, in order to perform HTTP01 validations during tests.
-#
 # The --unsafe-no-fsync decreases the load on the pod's filesystem [1],
 # which in turn decreases the end-to-end tests duration. It is OK for us to
 # use this flag because we are using a one-node etcd cluster. The fsync
@@ -20,8 +15,6 @@ kubeadmConfigPatches:
     kind: ClusterConfiguration
     metadata:
       name: config
-    networking:
-      serviceSubnet: 10.0.0.0/16
     etcd:
       local:
         extraArgs: