feat: add a kind cluster example (#1378)

Add examples/kind-with-registry.sh to start a kind cluster with zot as a
local registry.

Signed-off-by: Ramkumar Chinchani <rchincha@cisco.com>

examples/kind/kind-with-registry.sh

@@ -0,0 +1,66 @@
+#!/bin/sh
+set -o errexit
+
+# Reference: https://kind.sigs.k8s.io/docs/user/local-registry/
+
+# set no_proxy if applicable
+if [ ! -z "${no_proxy}" ]; then 
+  echo "Updating no_proxy env var";
+  export no_proxy=${no_proxy},kind-registry;
+  export NO_PROXY=${no_proxy};
+fi
+
+# create registry container unless it already exists
+reg_name='kind-registry'
+reg_port='5001'
+if [ "$(docker inspect -f '{{.State.Running}}' "${reg_name}" 2>/dev/null || true)" != 'true' ]; then
+  docker run \
+    -d --restart=always -p "127.0.0.1:${reg_port}:5000" --name "${reg_name}" \
+    ghcr.io/project-zot/zot-minimal-linux-amd64:latest
+fi
+
+# create a cluster with the local registry enabled in containerd
+cat <<EOF | kind create cluster --config=-
+kind: Cluster
+apiVersion: kind.x-k8s.io/v1alpha4
+containerdConfigPatches:
+- |-
+  [plugins."io.containerd.grpc.v1.cri".registry.mirrors."localhost:${reg_port}"]
+    endpoint = ["http://${reg_name}:5000"]
+EOF
+
+# connect the registry to the cluster network if not already connected
+if [ "$(docker inspect -f='{{json .NetworkSettings.Networks.kind}}' "${reg_name}")" = 'null' ]; then
+  docker network connect "kind" "${reg_name}"
+fi
+
+# Document the local registry
+# https://github.com/kubernetes/enhancements/tree/master/keps/sig-cluster-lifecycle/generic/1755-communicating-a-local-registry
+cat <<EOF | kubectl apply -f -
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: local-registry-hosting
+  namespace: kube-public
+data:
+  localRegistryHosting.v1: |
+    host: "localhost:${reg_port}"
+    help: "https://kind.sigs.k8s.io/docs/user/local-registry/"
+EOF
+
+# Copy an image
+skopeo copy --format=oci --dest-tls-verify=false docker://gcr.io/google-samples/hello-app:1.0 docker://localhost:5001/hello-app:1.0
+
+# Deploy
+kubectl create deployment hello-server --image=localhost:5001/hello-app:1.0
+
+# Check
+echo "Waiting for deployment/hello-server to be ready ..."
+kubectl wait deployment -n default hello-server --for condition=Available=True --timeout=90s
+
+# cleanup
+echo "Press a key to begin cleanup ..."
+read KEYPRESS
+kind delete cluster
+docker stop kind-registry
+docker rm kind-registry