[2.16] Fix how to get image ID on offline deployment (kubernetes-sigs…

…#7829)

* Add error handling for registorying images (kubernetes-sigs#7787)

When running the script, I faced the following error but it was
difficult to know the root problem due to lack of error handling.

  docker tag" requires exactly 2 arguments.
  See 'docker tag --help'.

  Usage:  docker tag SOURCE_IMAGE[:TAG] TARGET_IMAGE[:TAG]

  Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE

To investigate such errors easily, this adds an error handling.

* Fix how to get image ID on offline deployment (kubernetes-sigs#7808)

Previously IDs of container images were gotten from tar files of container
images but that way was wrong. If multiple json files are contained in a
tar file, the script got multiple IDs and tried to pass these IDs on
`docker tag` command. Then the command was failed.

This updates the script to get image IDs from `docker image inspect` command
to fix this issue.
In addition, this adds a check a registry container exists already or not
before deploying registry container to avoid a container conflict failure.

contrib/offline/manage-offline-container-images.sh

@@ -100,15 +100,35 @@ function register_container_images() {
 
 	tar -zxvf ${IMAGE_TAR_FILE}
 	sudo docker load -i ${IMAGE_DIR}/registry-latest.tar
-	sudo docker run --restart=always -d -p 5000:5000 --name registry registry:latest
 	set +e
-
+	sudo docker container inspect registry >/dev/null 2>&1
+	if [ $? -ne 0 ]; then
+		sudo docker run --restart=always -d -p 5000:5000 --name registry registry:latest
+	fi
 	set -e
+
 	while read -r line; do
 		file_name=$(echo ${line} | awk '{print $1}')
-		org_image=$(echo ${line} | awk '{print $2}')
-		new_image="${LOCALHOST_NAME}:5000/${org_image}"
-		image_id=$(tar -tf ${IMAGE_DIR}/${file_name} | grep "\.json" | grep -v manifest.json | sed s/"\.json"//)
+		raw_image=$(echo ${line} | awk '{print $2}')
+		new_image="${LOCALHOST_NAME}:5000/${raw_image}"
+		org_image=$(sudo docker load -i ${IMAGE_DIR}/${file_name} | head -n1 | awk '{print $3}')
+		image_id=$(sudo docker image inspect ${org_image} | grep "\"Id\":" | awk -F: '{print $3}'| sed s/'\",'//)
+		if [ -z "${file_name}" ]; then
+			echo "Failed to get file_name for line ${line}"
+			exit 1
+		fi
+		if [ -z "${raw_image}" ]; then
+			echo "Failed to get raw_image for line ${line}"
+			exit 1
+		fi
+		if [ -z "${org_image}" ]; then
+			echo "Failed to get org_image for line ${line}"
+			exit 1
+		fi
+		if [ -z "${image_id}" ]; then
+			echo "Failed to get image_id for file ${file_name}"
+			exit 1
+		fi
 		sudo docker load -i ${IMAGE_DIR}/${file_name}
 		sudo docker tag  ${image_id} ${new_image}
 		sudo docker push ${new_image}