Use appropriate kubeadm config version for kubernetes version

Signed-off-by: James Munnelly <james@munnelly.eu>

hack/ci/lib/cluster_create.sh

@@ -27,11 +27,20 @@ KIND="$(bazel info bazel-genfiles)/hack/bin/kind"
 
 # deploy_kind will deploy a kubernetes-in-docker cluster
 deploy_kind() {
+    # default to v1alpha3, if 1.11.x then use v1alpha2
+    vers="$(kubeVersion)"
+    config="v1alpha3"
+    if [[ "$vers" =~ v1\.11\..+ ]]; then
+        config="v1alpha2"
+    fi
+    echo "Booting Kubernetes version: $vers"
+    echo "Using kubeadm config api version '$config'"
+
     # create the kind cluster
     "${KIND}" create cluster \
         --name="${KIND_CLUSTER_NAME}" \
         --image="${KIND_IMAGE}" \
-        --config "${REPO_ROOT}"/test/fixtures/kind-config.yaml
+        --config "${REPO_ROOT}"/test/fixtures/kind/config-"$config".yaml
 }
 
 deploy_kind

hack/ci/lib/lib.sh

@@ -35,3 +35,10 @@ DOCKER_REPO="quay.io/jetstack"
 # This defaults to 'build' so it doesn't conflict with images built for any
 # other purpose
 DOCKER_TAG="build"
+
+function kubeVersion() {
+    echo $(docker run \
+        --entrypoint="cat" \
+        "${KIND_IMAGE}" \
+        /kind/version)
+}

test/fixtures/kind/config-v1alpha3.yaml

@@ -0,0 +1,19 @@
+# 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.
+
+apiVersion: kind.sigs.k8s.io/v1alpha1
+kind: Config
+# template for kubeadm config, "" -> the default template
+kubeadmConfigPatches:
+- |
+  # config generated by kind
+  apiVersion: kubeadm.k8s.io/v1alpha3
+  kind: MasterConfiguration
+  networking:
+    serviceSubnet: 10.0.0.0/16
+  kubeletConfiguration:
+    baseConfig:
+      clusterDNS:
+      - 10.0.0.10