install-docker-image-in-air-gapped-enviroment.md

How to install docker image in an air-gapped environment

Overview

The following steps show how to transfer a docker image from a machine that is on the internet to a machine that is not on the internet, (i.e. "air-gapped").

Contents

1. Set environment variables
2. Pull docker image to local repository
3. Package docker image
4. Transfer tar file to air-gapped machine
5. Unpackage docker image to local repository
6. Push image to private registry

Set environment variables

1. Using senzing/hello-world-on-hub-docker-com:latest as an example:

   export DOCKER_ACCOUNT=senzing
   export DOCKER_IMAGE=hello-world-on-hub-docker-com
   export DOCKER_TAG=latest

Pull docker image to local repository

1. On networked system:

   docker pull ${DOCKER_ACCOUNT}/${DOCKER_IMAGE}:${DOCKER_TAG}

   Reference: docker pull

Package docker image

1. Use docker save to package docker image. Example:

   docker save ${DOCKER_ACCOUNT}/${DOCKER_IMAGE}:${DOCKER_TAG} \
     --output ~/${DOCKER_ACCOUNT}-${DOCKER_IMAGE}-${DOCKER_TAG}.tar

   Reference: docker save

Transfer tar file to air-gapped machine

1. If scp or sftp connectivity is available, a network file transfer is possible. Example:

   export TARGET_HOST=my.example.com
   
   scp ~/${DOCKER_ACCOUNT}-${DOCKER_IMAGE}-${DOCKER_TAG}.tar ${TARGET_HOST}:

2. If truly air-gapped, copy tar file to a portable storage medium to transfer to air-gapped machine.

Unpackage docker image to local repository

1. On air-gapped machine, set environment variables. Using senzing/hello-world-on-hub-docker-com:latest as an example:

   export DOCKER_ACCOUNT=senzing
   export DOCKER_IMAGE=hello-world-on-hub-docker-com
   export DOCKER_TAG=latest

2. Unpackage tar file. Assuming tar file is in the ${HOME} directory, example:

   docker load \
     --input ~/${DOCKER_ACCOUNT}-${DOCKER_IMAGE}-${DOCKER_TAG}.tar

   Reference: docker load

Push image to private registry

1. Set environment variable. Example:

   export DOCKER_REGISTRY_URL=my.docker-registry.com:5000

2. Tag docker image for private docker registry.

   sudo docker tag \
     ${DOCKER_ACCOUNT}/${DOCKER_IMAGE}:${DOCKER_TAG} \
     ${DOCKER_REGISTRY_URL}/${DOCKER_ACCOUNT}/${DOCKER_IMAGE}:${DOCKER_TAG}

   Reference: docker tag

3. Push tagged image to private docker registry.

   sudo docker push ${DOCKER_REGISTRY_URL}/${DOCKER_ACCOUNT}/${DOCKER_IMAGE}:${DOCKER_TAG}

   Reference: docker push

4. Remove tag from local repository docker image.

   sudo docker rmi ${DOCKER_REGISTRY_URL}/${DOCKER_ACCOUNT}/${DOCKER_IMAGE}:${DOCKER_TAG}

   Reference: docker rmi