Makefile: Add kind-down target for deleting dev kind cluster

Signed-off-by: Anna Kapuscinska <anna@isovalent.com>

Makefile

@@ -362,6 +362,10 @@ endif
 .PHONY: kind-setup
 kind-setup: kind kind-install-tetragon ## Create a kind cluster and install local version of Tetragon.
 
+.PHONY: kind-down
+kind-down: ## Delete a kind cluster for Tetragon development.
+	./contrib/kind/delete-kind-cluster.sh
+
 ##@ Chores and generated files
 
 .PHONY: codegen protogen

contrib/kind/bootstrap-kind-cluster.sh

@@ -1,4 +1,4 @@
-#! /bin/bash
+#!/usr/bin/env bash
 
 error() {
     echo "$@" 1>&2

contrib/kind/delete-kind-cluster.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+error() {
+    echo "$@" 1>&2
+    exit 1
+}
+
+set -eu
+
+PROJECT_ROOT="$(git rev-parse --show-toplevel)"
+cd "$PROJECT_ROOT"
+source contrib/kind/conf
+
+if ! command -v kind &>/dev/null; then
+    error "kind is not in \$PATH! Bailing out!"
+fi
+
+usage() {
+	echo "usage: delete-kind-cluster.sh [OPTIONS]" 1>&2
+	echo "OPTIONS:" 1>&2
+    echo "       --cluster  override cluster name" 1>&2
+}
+
+while [ $# -ge 1 ]; do
+    if [ "$1" == "--cluster" ]; then
+        CLUSTER_NAME="$2"
+		shift 2
+    else
+        usage
+        exit 1
+	fi
+done
+
+
+if ! kind get clusters | grep "$CLUSTER_NAME" &>/dev/null; then
+    echo "Cluster $CLUSTER_NAME doesn't exist. Exiting." 1>&2
+    exit 0
+else
+    kind delete cluster --name "$CLUSTER_NAME"
+fi