[GHA] Enhance the checks for the kustomization.yaml files

Let's run on the currently used kustomize version by the operator but
also with the decently new kustomize version so we are sure we are
compatible with the upcoming features. This adds also STDERR output
check and compares the output between these two kustomize version.

Currently we have set kustomize 5.0.3 and 5.6.0.

Also this adds support for the execution on non-linux/non-amd64 archs.

Author: jstourac

ci/kustomize.sh

@@ -14,6 +14,8 @@
 # https://github.com/red-hat-data-services/rhods-operator/blob/7ccc405135f99c014982d7e297b8949e970dd750/go.mod#L28-L29
 # and then to match appropriate kustomize release https://github.com/kubernetes-sigs/kustomize/releases/tag/kustomize%2Fv5.0.3
 DEFAULT_KUSTOMIZE_VERSION=5.0.3
+# The latest kustomize version we want to check with to be sure we're prepared for the future
+THE_LATEST_KUSTOMIZE=5.6.0
 
 KUSTOMIZE_VERSION="${KUSTOMIZE_VERSION:-$DEFAULT_KUSTOMIZE_VERSION}"
 
@@ -27,7 +29,30 @@ function download_kustomize() {
     echo "---------------------------------------------------------------------------------"
     echo "Download kustomize '${kustomize_version}'"
     echo "---------------------------------------------------------------------------------"
-    wget --output-document="${kustomize_tar}" "https://github.com/kubernetes-sigs/kustomize/releases/download/kustomize/v${kustomize_version}/kustomize_v${kustomize_version}_linux_amd64.tar.gz"
+
+    # Detect OS
+    local uname_out
+    uname_out="$(uname -s)"
+    case "${uname_out}" in
+        Linux*)     os=linux;;
+        Darwin*)    os=darwin;;
+        *)          echo "Unsupported OS: ${uname_out}" && return 1;;
+    esac
+
+    # Detect architecture
+    local arch
+    arch="$(uname -m)"
+    case "${arch}" in
+        x86_64)   arch=amd64;;
+        arm64)    arch=arm64;;
+        aarch64)  arch=arm64;;
+        *)        echo "Unsupported architecture: ${arch}" && return 1;;
+    esac
+
+    local download_url="https://github.com/kubernetes-sigs/kustomize/releases/download/kustomize/v${kustomize_version}/kustomize_v${kustomize_version}_${os}_${arch}.tar.gz"
+    echo "Downloading from: ${download_url}"
+
+    wget --output-document="${kustomize_tar}" "${download_url}"
     tar -C "${tmp_dir}" -xvf "${kustomize_tar}"
     mv "${tmp_dir}/kustomize" "${kustomize_bin}"
 
@@ -46,22 +71,72 @@ function execute_kustomize() {
     echo "Starting to run kustomize '${kustomize_version}' for each kustomization.yaml file except components"
     echo "---------------------------------------------------------------------------------------------------"
     # We don't want to execute kustomization on the components part as it's not intended to be used that way.
-    find . -name "kustomization.yaml" | xargs dirname | grep -v "components" | xargs -t -I {} "${kustomize_bin}" build {} >"${kustomize_stdout}" 2>"${kustomize_stderr}"
+    # This first run is for the actual execution to get the generated output and eventual errors/warnings.
+    find . -name "kustomization.yaml" | xargs dirname | grep -v "components" | xargs -I {} "${kustomize_bin}" build {} >"${kustomize_stdout}" 2>"${kustomize_stderr}"
+    # This second run is with verbose output to see eventual errors/warnings together with which command they are present for easier debugging.
+    find . -name "kustomization.yaml" | xargs dirname | grep -v "components" | xargs --verbose -I {} "${kustomize_bin}" build {} >/dev/null
 
     echo "Let's print the STDERR:"
     cat "${kustomize_stderr}"
 }
 
+function check_the_results() {
+    local tmp_dir="${1}"
+    local kustomize_version_1="${2}"
+    local kustomize_version_2="${3}"
+
+    local kustomize_stdout_1="${tmp_dir}/kustomize-${kustomize_version_1}-stdout.yaml"
+    local kustomize_stderr_1="${tmp_dir}/kustomize-${kustomize_version_1}-stderr.txt"
+    local kustomize_stdout_2="${tmp_dir}/kustomize-${kustomize_version_2}-stdout.yaml"
+    local kustomize_stderr_2="${tmp_dir}/kustomize-${kustomize_version_2}-stderr.txt"
+
+    echo "---------------------------------------------------------------------------------"
+    echo "Checking the generated outputs - should be identical:"
+    echo "  - ${kustomize_stdout_1}"
+    echo "  - ${kustomize_stdout_2}"
+    echo "---------------------------------------------------------------------------------"
+    diff -u "${kustomize_stdout_1}" "${kustomize_stdout_2}" || {
+        echo "Generated files from kustomize differs between kustomize version ${kustomize_version_1} and ${kustomize_version_2}. Please check above!"
+        return 1
+    }
+
+    echo "---------------------------------------------------------------------------------"
+    echo "No log in STDERR outputs should be printed:"
+    echo "  - ${kustomize_stderr_1}"
+    echo "  - ${kustomize_stderr_2}"
+    echo "---------------------------------------------------------------------------------"
+    if [ -s "${kustomize_stderr_1}" ] || [ -s "${kustomize_stderr_2}" ]; then
+        echo "There were some logs generated to STDERR during the kustomize build. Please check the log above!"
+        return 1
+    fi
+}
+
+function run_check() {
+    local tmp_dir="${1}"
+    local kustomize_version="${2}"
+
+    download_kustomize "${tmp_dir}" "${kustomize_version}" || return 1
+    execute_kustomize "${tmp_dir}" "${kustomize_version}" || return 1
+}
+
 function main() {
+    local ret_code=0
+
     local tmp_dir
     tmp_dir=$(mktemp --directory -t kustomize-XXXXXXXXXX)
     echo "Running in the following temporary directory: '${tmp_dir}'"
 
-    download_kustomize "${tmp_dir}" "${KUSTOMIZE_VERSION}" || return 1
-    execute_kustomize "${tmp_dir}" "${KUSTOMIZE_VERSION}" || return 1
+    run_check "${tmp_dir}" "${KUSTOMIZE_VERSION}" || return 1
+    run_check "${tmp_dir}" "${THE_LATEST_KUSTOMIZE}" || return 1
+
+    # --------------------------------------------------------------------------------------
+
+    check_the_results "${tmp_dir}" "${KUSTOMIZE_VERSION}" "${THE_LATEST_KUSTOMIZE}" || return 1
+
+    exit "${ret_code}"
 }
 
 # allows sourcing the script into interactive session without executing it
 if [[ "${0}" == "${BASH_SOURCE[0]}" ]]; then
-    main $@
+    main "$@"
 fi