Added an export tar option

Dockerfile

@@ -1,4 +1,4 @@
-FROM public.ecr.aws/docker/library/alpine:3.20
+FROM public.ecr.aws/docker/library/alpine:3.21
 
 RUN apk add --no-cache docker-cli-buildx bash
 

action.yml

@@ -27,6 +27,9 @@ inputs:
     description: Comma separated list for building platform
     required: false
     default: ""
+  exportTarPath:
+    description: Whether and where to export the file as a tar image
+    required: false
 
 # Define your outputs here.
 outputs:

entrypoint.sh

@@ -6,6 +6,7 @@ INPUT_PUSH_IMAGE=$push
 INPUT_PULL_CACHE=$pullCache
 INPUT_DOCKERFILE_PATH=$path
 INPUT_PLATFORM=$platform
+INPUT_EXPORT_TAR=$exportTarPath
 
 set -e
 
@@ -43,6 +44,10 @@ if [ "$INPUT_PULL_CACHE" = "true" ]; then
   echo "Using docker image cache ${IMAGE_CACHE_NAME}"
 fi
 
+if [ -n "$INPUT_EXPORT_TAR" ]; then
+  DOCKER_BUILD_OPTIONS+=("--output" "type=docker,dest=$INPUT_EXPORT_TAR")
+fi
+
 DOCKER_BUILD_OPTIONS+=("${INPUT_DOCKERFILE_PATH}")
 # shellcheck disable=SC2145
 echo "Running docker buildx with options: ${DOCKER_BUILD_OPTIONS[@]}"
@@ -52,6 +57,6 @@ docker buildx build "${DOCKER_BUILD_OPTIONS[@]}"
 echo "Cleaning up docker"
 docker system prune --all --force
 
-echo "imageName=${IMAGE_NAME}" >>"$GITEA_OUTPUT"
+echo "imageName=${IMAGE_NAME}" >> "$GITEA_OUTPUT"
 
 exit 0