validate_helm_chart: add support for oci repositories

Signed-off-by: André Martins <andre@cilium.io>

Author: aanm

validate_helm_chart.sh

@@ -8,8 +8,17 @@ shopt -s expand_aliases
 
 DOCKER=${DOCKER:-docker}
 
+HELM_CACHE_DIR=$(mktemp -d)
+trap 'rm -rf "$HELM_CACHE_DIR"' EXIT
+
 helm() {
-  "${DOCKER}" run --user "$(id -u):$(id -g)" --rm -v "$(pwd)":/apps alpine/helm:3.15.1 "$@"
+  "${DOCKER}" run --user "$(id -u):$(id -g)" --rm \
+    -v "$(pwd)":/apps \
+    -v "$HELM_CACHE_DIR":/tmp/helm \
+    -e XDG_CACHE_HOME=/tmp/helm \
+    -e XDG_CONFIG_HOME=/tmp/helm \
+    -e XDG_DATA_HOME=/tmp/helm \
+    alpine/helm:3.15.1 "$@"
 }
 
 yq () {
@@ -55,8 +64,25 @@ main() {
       exit 1
   fi
 
-  APP=$(helm show chart "$CHART" | yq e '.name' -)
-  CHART_VERSION=$(helm show chart "$CHART" | yq e '.version' -)
+  if [[ "$CHART" =~ ^oci:// ]]; then
+      OCI_BASE=$(echo "$CHART" | cut -d':' -f1,2)  # oci://registry/path/chart
+      OCI_VERSION=$(echo "$CHART" | rev | cut -d':' -f1 | rev)  # version
+
+      if [[ "$OCI_BASE" == "$CHART" ]]; then
+          echo "ERROR: OCI chart reference must include version (e.g., oci://registry/chart:1.0.0)"
+          usage
+          exit 1
+      fi
+
+      CHART_REF="$OCI_BASE"
+      VERSION_FLAG="--version $OCI_VERSION"
+  else
+      CHART_REF="$CHART"
+      VERSION_FLAG=""
+  fi
+
+  APP=$(helm show chart $VERSION_FLAG "$CHART_REF" | yq e '.name' -)
+  CHART_VERSION=$(helm show chart $VERSION_FLAG "$CHART_REF" | yq e '.version' -)
   if [ "$APP" == "cilium" ]; then
     IMAGE_PATHS=("${CILIUM_IMAGE_PATHS[@]}")
   elif [ "$APP" == "tetragon" ]; then
@@ -67,7 +93,7 @@ main() {
   fi
 
   for path in "${IMAGE_PATHS[@]}"; do
-    tag=$(helm show values --jsonpath "$path" "$CHART")
+    tag=$(helm show values $VERSION_FLAG --jsonpath "$path" "$CHART_REF")
     if [ "$tag" == "v$CHART_VERSION" ]; then
       echo "SUCCESS: $APP $path=$tag matches chart version $CHART_VERSION"
     else