Add benchmark for containerized KRM function in kustomize

hack/krmFunctionBenchmark/benchmark.sh

@@ -0,0 +1,67 @@
+#! /bin/bash
+
+set -e
+
+KUSTOMIZE_EXEC=kustomize
+KUSTOMIZE_FLAGS="build --enable_alpha_plugins --enable-exec"
+
+function build_label_namespace_exec {
+    cd label_namespace/execfn
+    . build.sh
+    cd -
+}
+
+function build_tshirt_exec {
+    cd example_tshirt/execfn
+    . build.sh
+    cd -
+}
+
+function build_exec {
+    echo "Building exec functions..."
+    build_tshirt_exec
+    build_label_namespace_exec
+    echo "Done. Start running benchmark."
+}
+
+function run_fn {
+    local loop=$1
+    local type=$2
+    local dir=$3
+    echo -e "=== Running ${type} ${loop} times ==="
+    cd $dir
+    local begin_time=$(date +%s%N)
+    for ((i = 0; i < $loop; i++))
+    do
+        $KUSTOMIZE_EXEC $KUSTOMIZE_FLAGS > /dev/null
+        echo -en "\r$i/$loop"
+    done
+    local end_time=$(date +%s%N)
+    local time_diff=$(($end_time - $begin_time))
+    local time_diff_s=$(echo "${time_diff} / 1000 / 1000 / 1000" | bc -l)
+    echo -e "\n=== Time used: ==="
+    echo "${time_diff_s}s"
+    cd -
+}
+
+function run_label_namespace_benchmark {
+    local loop=$1
+    run_fn $loop "Label Namespace Transformer Exec Function" "label_namespace/execfn"
+    run_fn $loop "Label Namespace Transformer Container Function" "label_namespace/containerfn"
+}
+
+function run_tshirt_benchmark {
+    local loop=$1
+    run_fn $loop "T-shirt Example Exec Function" "example_tshirt/execfn"
+    run_fn $loop "T-shirt Example Container Function" "example_tshirt/containerfn"
+}
+
+loops=(10 100 1000)
+
+build_exec
+
+for l in "${loops[@]}"
+do
+    run_label_namespace_benchmark $l
+    run_tshirt_benchmark $l
+done