Dockerfile - Container image definition for testing
01_create_image.sh - script for creating container image locally
02_start_container_with_image.sh - script for starting container from created image

Purpose

Provides a reproducible testing environment that allows:

Running the post-installation script without affecting the host system
Real apt installations (isolated in container)
Testing script logic, prompts, and error handling
Validating syntax and tracing execution

Features

The Dockerfile includes:

Ubuntu 22.04 base image
Passwordless sudo for real apt installations
Useful utilities: bash, wget, tar, curl, gnupg, ca-certificates, file, procps, sudo

Usage

Build the test image

Run the prepared shell script to build the image

cd post_installation_script_test
sh 01_create_image.sh

Start a container for testing

Run the prepared shell script start a new container for testing based in the image and remove container after it is stopped. After container is started an interactive session is started into the container.

cd post_installation_script_test
sh 02_start_container_with_image.sh

Test the script file in the running container

After container is started an interactive session was started in the container and the script can be started for testing

ls -al
sh <scriptName>.sh

Security Notes

The script is mounted read-only (:ro flag) to prevent container from modifying host files
All apt installations are real but isolated in the container
Use --tmpfs /tmp:rw for any temporary writes inside the container
Container is automatically removed after exit (--rm flag)

README.md

Post-Installation Script Testing