add support to `eessi_container.sh` for using `unionfs` overlay tool #61

	# documentation: https://help.github.com/en/articles/workflow-syntax-for-github-actions
	name: Check for EESSI init shell scripts to load eessi software module in software.eessi.io
	on:
	push:
	branches: [ "*-software.eessi.io" ]
	pull_request:
	workflow_dispatch:
	permissions:
	contents: read # to fetch code (actions/checkout)
	jobs:
	build:
	runs-on: ubuntu-24.04
	strategy:
	fail-fast: false
	matrix:
	EESSI_VERSION:
	- '2023.06'
	EESSI_SOFTWARE_SUBDIR_OVERRIDE:
	- x86_64/intel/haswell
	steps:
	- name: Check out software-layer repository
	uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1

	- name: Mount EESSI CernVM-FS pilot repository
	uses: cvmfs-contrib/github-action-cvmfs@55899ca74cf78ab874bdf47f5a804e47c198743c # v4.0
	with:
	cvmfs_config_package: https://github.com/EESSI/filesystem-layer/releases/download/latest/cvmfs-config-eessi_latest_all.deb
	cvmfs_http_proxy: DIRECT
	cvmfs_repositories: software.eessi.io

	- name: Fix EESSI version in lmod init scripts
	run: \|
	for shell in $(ls init/lmod); do
	sed -i "s/__EESSI_VERSION_DEFAULT__/${{matrix.EESSI_VERSION}}/g" init/lmod/${shell}
	done

	- name: Clone assert.sh script
	run: git clone https://github.com/lehmannro/assert.sh.git

	- name: Install missing shells
	run: \|
	sudo apt update
	sudo apt install zsh ksh fish
	echo "# INIT ZSH" > ~/.zshrc

	- name: Run tests for available shells
	run: \|
	.github/workflows/scripts/test_init_scripts.sh "bash" "zsh" "ksh" "fish" "csh"

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