From 73df2332a3aca209f54e09255fb22592e29efacd Mon Sep 17 00:00:00 2001
From: Nicholas Baker <nbakerd@amazon.com>
Date: Fri, 16 Aug 2024 12:38:14 -0700
Subject: [PATCH] Remove empty string fallback on cached image list

---
 templates/al2/provisioners/install-worker.sh | 35 +++++++++++---------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/templates/al2/provisioners/install-worker.sh b/templates/al2/provisioners/install-worker.sh
index 2d3802763..311289a7c 100644
--- a/templates/al2/provisioners/install-worker.sh
+++ b/templates/al2/provisioners/install-worker.sh
@@ -446,6 +446,7 @@ if [[ "$CACHE_CONTAINER_IMAGES" == "true" ]] && ! [[ ${ISOLATED_REGIONS} =~ $BIN
   REGIONS=$(aws ec2 describe-regions --all-regions --output text --query 'Regions[].[RegionName]')
 
   for img in "${CACHE_IMGS[@]:-}"; do
+    if [ -z "${img}" ]; then continue; fi
     ## only kube-proxy-minimal is vended for K8s 1.24+
     if [[ "${img}" == *"kube-proxy:"* ]] && [[ "${img}" != *"-minimal-"* ]] && vercmp "${K8S_MINOR_VERSION}" gteq "1.24"; then
       continue
@@ -458,6 +459,7 @@ if [[ "$CACHE_CONTAINER_IMAGES" == "true" ]] && ! [[ ${ISOLATED_REGIONS} =~ $BIN
     ## iterate through decrementing the build version each time
     for build_version in $(seq "${eksbuild_version}" -1 1); do
       img=$(echo "${img}" | sed -E "s/eksbuild.[0-9]+/eksbuild.${build_version}/")
+      echo "Pulling image [${img}]"
       if /etc/eks/containerd/pull-image.sh "${img}"; then
         PULLED_IMGS+=("${img}")
         break
@@ -469,21 +471,24 @@ if [[ "$CACHE_CONTAINER_IMAGES" == "true" ]] && ! [[ ${ISOLATED_REGIONS} =~ $BIN
 
   #### Tag the pulled down image for all other regions in the partition
   for region in ${REGIONS[*]}; do
-    for img in "${PULLED_IMGS[@]:-}"; do
-      region_uri=$(/etc/eks/get-ecr-uri.sh "${region}" "${AWS_DOMAIN}")
-      regional_img="${img/$ECR_URI/$region_uri}"
-      sudo ctr -n k8s.io image tag "${img}" "${regional_img}" || :
-      ## Tag ECR fips endpoint for supported regions
-      if [[ "${region}" =~ (us-east-1|us-east-2|us-west-1|us-west-2|us-gov-east-1|us-gov-west-1) ]]; then
-        regional_fips_img="${regional_img/.ecr./.ecr-fips.}"
-        sudo ctr -n k8s.io image tag "${img}" "${regional_fips_img}" || :
-        sudo ctr -n k8s.io image tag "${img}" "${regional_fips_img/-eksbuild.1/}" || :
-      fi
-      ## Cache the non-addon VPC CNI images since "v*.*.*-eksbuild.1" is equivalent to leaving off the eksbuild suffix
-      if [[ "${img}" == *"-cni"*"-eksbuild.1" ]]; then
-        sudo ctr -n k8s.io image tag "${img}" "${regional_img/-eksbuild.1/}" || :
-      fi
-    done
+    if [ "${#PULLED_IMGS[@]:-}" -gt 0 ]; then
+      for img in "${PULLED_IMGS[@]:-}"; do
+        if [ -z "${img}" ]; then continue; fi
+        region_uri=$(/etc/eks/get-ecr-uri.sh "${region}" "${AWS_DOMAIN}")
+        regional_img="${img/$ECR_URI/$region_uri}"
+        sudo ctr -n k8s.io image tag "${img}" "${regional_img}" || :
+        ## Tag ECR fips endpoint for supported regions
+        if [[ "${region}" =~ (us-east-1|us-east-2|us-west-1|us-west-2|us-gov-east-1|us-gov-west-1) ]]; then
+          regional_fips_img="${regional_img/.ecr./.ecr-fips.}"
+          sudo ctr -n k8s.io image tag "${img}" "${regional_fips_img}" || :
+          sudo ctr -n k8s.io image tag "${img}" "${regional_fips_img/-eksbuild.1/}" || :
+        fi
+        ## Cache the non-addon VPC CNI images since "v*.*.*-eksbuild.1" is equivalent to leaving off the eksbuild suffix
+        if [[ "${img}" == *"-cni"*"-eksbuild.1" ]]; then
+          sudo ctr -n k8s.io image tag "${img}" "${regional_img/-eksbuild.1/}" || :
+        fi
+      done
+    fi
   done
 fi