add scripts for helm testing

hack/check-helm.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# We need a clean Kubernetes cluster to run this script.
+
+set -e
+
+cd deploy/chart
+
+kubectl create -f ./crds
+
+helm lint
+helm install alibaba-cloud-csi-driver . --namespace kube-system --dry-run=server
+
+for v in values-*.yaml; do
+    helm lint --values "$v"
+    helm install alibaba-cloud-csi-driver . --namespace kube-system --dry-run=server --values "$v"
+done
+
+kubectl delete -f ./crds

test/install-or-upgrade.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+# If helm chart is changed, try install upstream version, then upgrade to local version,
+# to ensure all changes are valid. e.g. we don't change some immutable fields.
+
+set -e
+
+UPSTREAM=${UPSTREAM:-"origin/master"}
+
+if ! git diff --exit-code --stat "$UPSTREAM" HEAD -- deploy/chart; then
+    echo "helm chart is changed, installing $UPSTREAM version first"
+    git worktree add --detach --no-checkout ../upstream "$UPSTREAM"
+    ( cd ../upstream && git checkout HEAD -- deploy/chart )
+
+    helm install --namespace kube-system alibaba-cloud-csi-driver ../upstream/deploy/chart "$@"
+    git worktree remove --force ../upstream
+fi
+
+echo installing local version
+helm upgrade --install --namespace kube-system alibaba-cloud-csi-driver ./deploy/chart "$@"