hack: add prepare-webhook-on-kind.sh

Inspired from 7bb5657c4d. I used this to help accept 2 stories today.

Signed-off-by: Andrew Keesler <akeesler@vmware.com>

hack/prepare-webhook-on-kind.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+
+# Copyright 2021 the Pinniped contributors. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+#
+# This script deploys a WebhookAuthenticator to use for manual testing. It
+# assumes that you have run hack/prepare-for-integration-tests.sh while pointed
+# at the current cluster.
+#
+
+set -euo pipefail
+
+# Change working directory to the top of the repo.
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+# Read the env vars output by hack/prepare-for-integration-tests.sh.
+source /tmp/integration-test-env
+
+# Create WebhookAuthenticator.
+cat <<EOF | kubectl apply -f - 1>&2
+kind: WebhookAuthenticator
+apiVersion: authentication.concierge.pinniped.dev/v1alpha1
+metadata:
+  name: my-webhook
+spec:
+  endpoint: ${PINNIPED_TEST_WEBHOOK_ENDPOINT}
+  tls:
+    certificateAuthorityData: ${PINNIPED_TEST_WEBHOOK_CA_BUNDLE}
+EOF
+
+# Use the CLI to get a kubeconfig that will use this WebhookAuthenticator.
+go build -o /tmp/pinniped ./cmd/pinniped
+/tmp/pinniped get kubeconfig --static-token "$PINNIPED_TEST_USER_TOKEN" >/tmp/kubeconfig-with-webhook-auth.yaml
+
+echo "export KUBECONFIG=/tmp/kubeconfig-with-webhook-auth.yaml"