Introduction

Containerization is a method to isolate computing environment (operating system, data, software, configurations, etc.) into reusable packages called images. These are binary files which can easily be transferred between different machines. Images are instantiated into running Containers by a Container Engine. From user perspectiveuser perspective, working with the Container is similar to working with another operating system on the shared hardware resources. This resembles what Virtual Machines provide. However, there are important technical differences between Container and Virtual Machine technologies. Mainly, any number of Containers can be executed by a single Container Engine on a single operating system. In case of Virtual Machines, each runs its own operating system with its own layer of hardware abstraction. In consequence, Containers are in general quicker to start and easier to operate.

Docker

The main Containerization technology used now is Docker. It consists of image file format description, the Container Engine and other components. It is available for Linux, macOS and Windows.

For more information, check check Docker overview

uDocker

uDocker is ":

a basic user tool to execute simple docker containers in user space without requiring root privileges

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For more information, check check indigo-dc/udocker

Docker vs uDocker

Important: While uDocker has mostly identical commands and parameters as Docker, there are some minor differences:

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• Docker on your own computer:

  Code Block
  language bash
  scp login.eufus.eu:~g2tomz/public/imas-installer-20180921112143.tar.xz ./ xzcat imas-installer-20180921112143.tar.xz | docker load

• uDocker on Gateway:

  Code Block
  language bash
  xzcat~/.local/bin/udocker load -i ~g2tomz/public/imas-installer-20180921112143.tar.xz | ~/.local/bin/udocker load

Demonstration 1: Python script

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• Check correctness of the results, on Gateway:

  Code Block
  language bash
  idsdump 1 1 pf_active

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