BasicTemplate.def

# This line specifies the bootstrap agent that determines the base of your container.
# Here, we are using a Docker image as the base.
Bootstrap: docker

# The 'From' keyword specifies the Docker image you want to base your container on.
# In this case, we're using the Ubuntu 20.04 LTS image.
From: ubuntu:20.04

# The '%post' section runs during the container's build process.
# This is where you install any software and dependencies your container needs.
%post
    # Update the package list
    apt-get update
    
    # Install a basic text editor (nano)
    apt-get install -y nano
    
# The '%environment' section sets environment variables within the container.
# These are available during runtime and can be used to configure your software.
%environment
    export MY_VARIABLE=my_value

# The '%runscript' section specifies the commands that will be run when the container
# is executed. You can think of it as the container's 'main' function.
%runscript
    # Echo a greeting
    echo "Hello, this is your container speaking."
    
    # Use the environment variable
    echo "MY_VARIABLE is set to $MY_VARIABLE"