Add a TOSCA component to load a docker image from a tar archive

[laurentganne]

The TOSCA component org.ystia.docker.containers.docker.generic.nodes.GenericContainer allows to create a docker container from an image in a docker repository.
But In some use cases, the image is not available in a docker repository. This image is available in the filesystem as a tar archive.

A new TOSCA component could be added in the Forge to be able to load a docker image from a tar archive.

[loicalbertin]

Are you thinking about a DockerImagecomponent that will manage images in the local registry?
I think it could be interesting as we would be able to download an image from a registry, load it from a tgz file or even build it... and finally remove it in delete phase.
We could do this incrementally, WDYT?

We may take inspiration from https://docs.ansible.com/ansible/latest/collections/community/general/docker_image_module.html#ansible-collections-community-general-docker-image-module

[laurentganne]

Actually as this ansible module has many parameters, some making sense only for a build, others only for a load, etc... I was thinking to make specialized components, like in this implementation: https://github.com/ystia/forge/blob/feature/GH-140-docker-image-loader/org/ystia/docker/images/types.yml of an Image Loader component, and we could have another component called image builder, etc... This way I'm exposing just the properties I need for the operation I wan to do (here load a tar archive), what do you think ?

[loicalbertin]

Makes sense.