Using Singularity to unpack and use a .tar.gz file

Question

I have a zipped file "filename.docker.tar.gz" that I am supposed to extract using docker, using

docker load -i filename.docker.tar.gz

docker run --name itsgreat -it filename

However, I dont have docker installed in my HPC cluster and the admin has recommended me to use singularity. I have been through singularity tutorials and I am not having clarity on how I should proceed (exact commands in singularity that would do the job, in lieu of docker). Help and suggestions appreciated.

Answer 1

1) convert from docker to singularity image like here:

singularity build lolcow_tar.sif docker-archive://lolcow.tar

2) run with shell or exec function:

singularity shell [some_options] lolcow_tar.sif

Сheck that after convertation process all changes which you've made to the docker container are saved (some changes may be lost). If it so, then you probably want to change all again in sandbox mode or with the definition file (like docker file).