Add script to check container images' agent versions (#1404)

* add check-images.sh to check installed nginx and agent version from remote registry

* improve usage and comments

* use skopeo container image

* fix skopeo image pull url

* fix image path reference format

* [skip ci] split tag and image name, exit if image pull fails

* remove action

Author: sean-breen

scripts/check-images.sh

@@ -0,0 +1,83 @@
+#!/usr/bin/env bash
+set -euo pipefail
+#set -x # Uncomment for debugging
+
+usage() {
+    echo "$0"
+    echo
+    echo "  Check and pull NGINX Agent Docker images from the official NGINX Docker registry."
+    echo "    Args:"
+    echo "      1. Registry URL (default: docker-registry.nginx.com/nginx)"
+    echo "      2. Image Name (default: agentv3)"
+    echo "      3. Search Pattern (optional): A regex pattern to filter tags before checking versions"
+    echo
+    echo "  Usage:"
+    echo "    > $0 <registry-url> <image-name> [search-pattern]"
+    echo
+    echo "  Example:"
+    echo "    Search for all tags for the 'agentv3' image in the NGINX Docker registry:"
+    echo "      > $0 docker-registry.nginx.com/nginx agentv3"
+    echo
+    echo "    Search for all tags containing 'alpine' for the 'agentv3' image in the NGINX Docker registry:"
+    echo "      > $0 docker-registry.nginx.com/nginx agentv3 alpine"
+    exit 0
+}
+
+while getopts "h" opt; do
+    case ${opt} in
+        h )
+            usage
+            ;;
+        \? )
+            usage
+            ;;
+    esac
+done
+
+# Input parameters with defaults
+REGISTRY_URL=${1:-"docker-registry.nginx.com/nginx"}
+IMAGE_NAME=${2:-"agentv3"}
+RE_PATTERN=${3:-""}
+IMAGE_PATH="${REGISTRY_URL}/${IMAGE_NAME}"
+CONTAINER_TOOL=docker
+SKOPEO_IMAGE="quay.io/skopeo/stable"
+SKOPEO_TAG="latest"
+
+# Check for docker installation
+if ! command -v ${CONTAINER_TOOL} &> /dev/null; then
+    echo "${CONTAINER_TOOL} could not be found."
+    # check podman as an alternative
+    CONTAINER_TOOL=podman
+    if ! command -v ${CONTAINER_TOOL} &> /dev/null; then
+        echo "Neither docker nor podman could be found. Please install one of them to proceed."
+        exit 1
+    fi
+fi
+
+echo "Using container tool: ${CONTAINER_TOOL}"
+${CONTAINER_TOOL} --version
+
+echo "Getting skopeo tool..."
+${CONTAINER_TOOL} pull ${SKOPEO_IMAGE}:${SKOPEO_TAG} || { echo "Failed to pull skopeo image"; exit 1; }
+
+echo "Checking images in ${REGISTRY_URL}/${IMAGE_NAME}"
+echo "Saving all tags to ${IMAGE_NAME}_tags.txt"
+${CONTAINER_TOOL} run quay.io/skopeo/stable list-tags docker://${IMAGE_PATH} | jq -r '.Tags[]' > ${IMAGE_NAME}_tags.txt
+echo $(wc -l < ${IMAGE_NAME}_tags.txt) "tags fetched."
+
+# Filter out tags that end with four or more digits (nightly/build tags)
+grep -Ev '\d{4,}$' ${IMAGE_NAME}_tags.txt | sort -u > ${IMAGE_NAME}_filteredtags.txt
+echo $(wc -l < ${IMAGE_NAME}_filteredtags.txt) "tags after filtering."
+
+# Search for tags matching the provided pattern
+FOUND=($(grep -E "${RE_PATTERN}" ${IMAGE_NAME}_filteredtags.txt))
+echo "tags matching '${RE_PATTERN}':" ${#FOUND[@]}
+echo "${FOUND[@]}" | sed 's/ /\n/g'
+
+for tag in "${FOUND[@]}"; do
+    echo ":: ${IMAGE_PATH}:$tag"
+    ${CONTAINER_TOOL} pull ${IMAGE_PATH}:$tag > /dev/null 2>&1
+    ${CONTAINER_TOOL} run ${IMAGE_PATH}:$tag nginx -v
+    ${CONTAINER_TOOL} run --rm ${IMAGE_PATH}:$tag nginx-agent --version | sed 's/version/version:/g' # --rm to clean up container after run
+done
+