chore: make sure installed chartsnap version matches desired

Makefile

@@ -16,8 +16,7 @@ kube-linter:
 
 .PHONY: chartsnap
 chartsnap:
-	@helm plugin list | grep chartsnap > /dev/null || \
-	helm plugin install https://github.com/jlandowner/helm-chartsnap --version $(CHARTSNAP_VERSION)
+	./scripts/install-chartsnap.sh
 
 .PHONY: lint
 lint: tools lint.charts.kong lint.shellcheck

scripts/install-chartsnap.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+CHARTSNAP_VERSION="0.3.1"
+
+# Only install the plugin if it is not already installed or if the version is different.
+if [[ $(helm plugin list | grep chartsnap | grep -Eo '[0-9]{1,}.[0-9]{1,}.[0-9]{1,}') == "${CHARTSNAP_VERSION}" ]]; then
+  echo "INFO: chartsnap plugin is already installed and up to date"
+else
+  echo "INFO: Installing chartsnap plugin"
+  if [ $(helm plugin list | grep -ic chartsnap) -eq 1 ]; then
+    echo "INFO: Uninstalling existing chartsnap plugin - version mismatch"
+    helm plugin uninstall chartsnap
+  fi
+  helm plugin install https://github.com/jlandowner/helm-chartsnap --version "${CHARTSNAP_VERSION}"
+fi