How to save docker image locally using docker compose and then install it in another server offline?

ref: https://milvus.io/docs/install_offline-docker.md

Download files and images

To install Milvus offline, you need to pull and save all images in an online environment first, and then transfer them to the target host and load them manually.

1. Download an installation file.

• For Milvus standalone:

//github.com/milvus-io/milvus/releases/download/v2.2.2/milvus-standalone-docker-compose.yml -O docker-compose.yml

• For Milvus cluster:

//github.com/milvus-io/milvus/releases/download/v2.2.2/milvus-cluster-docker-compose.yml -O docker-compose.yml

2. Download requirement and script files.

//raw.githubusercontent.com/milvus-io/milvus/master/deployments/offline/requirements.txt

3. Pull and save images.

pip3 install -r requirements.txt
python3 save_image.py --manifest docker-compose.yml

The images are stored in the /images folder.

4. Load the images.

cd

Install Milvus offline

Having transferred the images to the target host, run the following command to install Milvus offline.

docker-compose -f docker-compose.yml up -d

Uninstall Milvus

To uninstall Milvus, run the following command.

docker-compose -f docker-compose.yml down


===

requirements.txt:-

docker==5.0.0
nested-lookup==0.2.22

===
save_image.py:-

import argparse
import docker
import gzip
import os
import yaml
from nested_lookup import nested_lookup


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description="Save Docker images")

    parser.add_argument("--manifest",
                        required=True,
                        help="Path to the manifest yaml")
    parser.add_argument("--save_path",
                        type=str,
                        default='images',
                        help='Directory to save images to')
    arguments = parser.parse_args()

    with open(arguments.manifest, 'r') as file:
        template = file.read()

    images=[]
    parts = template.split('---')
    for p in parts:
        y = yaml.safe_load(p)
        matches = nested_lookup("image", y)
        if (len(matches)):
                images += matches

    save_path = arguments.save_path
    if not os.path.isdir(save_path):
        os.mkdir(save_path)

    client = docker.from_env()
    for image_name in set(images):
        file_name = (image_name.split(':')[0].replace("/", "-"))
        f = gzip.open(save_path + "/" + file_name + '.tar.gz', 'wb')
        try:
            image = client.images.get(image_name)
            if image.id:
              print ("docker image \"" + image_name + "\" already exists.")
        except docker.errors.ImageNotFound:
            print ("docker pull " + image_name + " ...")
            image = client.images.pull(image_name)
        image_tar = image.save(named=True)
        f.writelines(image_tar)
        f.close()

    print("Save docker images to \"" + save_path + "\"")

===
docker-compose.yml:-

version: '3.5'

services:
  etcd:
    container_name: milvus-etcd
    image: quay.io/coreos/etcd:v3.5.0
    environment:
      - ETCD_AUTO_COMPACTION_MODE=revision
      - ETCD_AUTO_COMPACTION_RETENTION=1000
      - ETCD_QUOTA_BACKEND_BYTES=4294967296
      - ETCD_SNAPSHOT_COUNT=50000
    volumes:
      - ${DOCKER_VOLUME_DIRECTORY:-.}/volumes/etcd:/etcd
    command: etcd -advertise-client-urls=http://127.0.0.1:2379 -listen-client-urls http://0.0.0.0:2379 --data-dir /etcd

  minio:
    container_name: milvus-minio
    image: minio/minio:RELEASE.2022-03-17T06-34-49Z
    environment:
      MINIO_ACCESS_KEY: minioadmin
      MINIO_SECRET_KEY: minioadmin
    ports:
      - "9001:9001"
    volumes:
      - ${DOCKER_VOLUME_DIRECTORY:-.}/volumes/minio:/minio_data
    command: minio server /minio_data --console-address ":9001"
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:9000/minio/health/live"]
      interval: 30s
      timeout: 20s
      retries: 3

  standalone:
    container_name: milvus-standalone
    image: milvusdb/milvus:v2.2.2
    command: ["milvus", "run", "standalone"]
    environment:
      ETCD_ENDPOINTS: etcd:2379
      MINIO_ADDRESS: minio:9000
    volumes:
      - ${DOCKER_VOLUME_DIRECTORY:-.}/volumes/milvus:/var/lib/milvus
    ports:
      - "19530:19530"
      - "9091:9091"
    depends_on:
      - "etcd"
      - "minio"

networks:
  default:
    name: milvus