how to package a docker image in a single file

Question

I have a 5GB docker image named "ubuntu-dev-update-15", which I developed on my local Ubuntu 14 dev machine. In that image I have everything I need to do my development work. Now I need to be able to send this image to a different linux host. What is the procedure for doing that?

Answer 1

If your different linux host is on the same network you can transfer saved image using FTP or local HTTP server or share to transfer the file locally. Usage of Save :

docker save [OPTIONS] IMAGE [IMAGE...]

Example : sudo docker save -o ubuntu.tar ubuntu:precise ubuntu:unicorn

where -o saves to a file, instead of STDOUT. Transfer this tar file to the other linux host.Load this tar file in the new host using: docker load [OPTIONS]

Example: sudo docker load --input fedora.tar

where --input reads from a tar archive file, instead of STDIN.

Answer 2

Docker hub is one option to move your file. But from a production point of view it is better to run a registry(place to store images) in the machine where you want to send your image .

For example you want to send your image from system1 to system2. Let your image name be my_image.

Now open a registry in system1 by running

docker run -p <system1-ip>:5000:5000 -d registry

push your image into that registry :

You need to rename the image with :5000/my_image by using tag option

docker tag my_image <system1-ip>:5000/my_image

Now push into registry by using push command

docker push <system1-ip>:5000/my_image

Now go to system2 and pull your image from registry .

  docker pull <system1-ip>:5000/my_image

This is the most secured way of transferring images. Reference link creating a private repository