Adding docker ci images getter scripts

Signed-off-by: Peter Zhu <zhujiaxi@amazon.com>

docker/ci/get-ci-images.sh

@@ -0,0 +1,72 @@
+#!/bin/bash
+
+# Copyright OpenSearch Contributors
+# SPDX-License-Identifier: Apache-2.0
+#
+# The OpenSearch Contributors require contributions made to
+# this file be licensed under the Apache-2.0 license or a
+# compatible open source license.
+
+# This script is to return the latest ci docker images
+
+set -e
+
+function usage() {
+    echo ""
+    echo "This script is used to return the latest ci docker images (mostly used in distribution build or integtest pipelines)"
+    echo "This script will not return any older images, please check 'manifests' directory for those images"
+    echo "--------------------------------------------------------------------------"
+    echo "Usage: $0 [args]"
+    echo ""
+    echo "Required arguments:"
+    echo -e "-p PLATFORM\tSpecify the ci image target platform, e.g. 'rockylinux8(default)', 'centos7', 'ubuntu2004' or 'windows2019-servercore'"
+    echo -e "-u USAGE\tSpecify the ci image target usage, e.g. 'opensearch(default)' or 'opensearch-dashboards' or 'systemd-base'"
+    echo -e "-t TYPE\tSpecify the usages ci image target type, e.g. 'build(default)' or 'integtest'"
+    echo ""
+    echo "Optional arguments:"
+    echo -e "-h\t\tPrint this message."
+    echo "--------------------------------------------------------------------------"
+}
+
+while getopts ":hp:u:t:" arg; do
+    case $arg in
+        h)
+            usage
+            exit 1
+            ;;
+        p)
+            PLATFORM=$OPTARG
+            ;;
+        u)
+            USAGE=$OPTARG
+            ;;
+        t)
+            TYPE=$OPTARG
+            ;;
+        :)
+            echo "-${OPTARG} requires an argument"
+            usage
+            exit 1
+            ;;
+        ?)
+            echo "Invalid option: -${arg}"
+            exit 1
+            ;;
+    esac
+done
+
+# Validate the required parameters to present
+if [ -z "$PLATFORM" ]; then
+    PLATFORM="rockylinux8"
+fi
+
+if [ -z "$USAGE" ]; then
+    USAGE="opensearch"
+fi
+
+if [ -z "$TYPE" ]; then
+    TYPE="build"
+fi
+
+# Run script
+crane ls public.ecr.aws/opensearchstaging/ci-runner | grep -Eo '.*v[0-9]' | sort -r | uniq | grep $PLATFORM-$USAGE-$TYPE