distrobox-assemble

#!/bin/sh
# SPDX-License-Identifier: GPL-3.0-only
#
# This file is part of the distrobox project:
#    https://github.com/89luca89/distrobox
#
# Copyright (C) 2021 distrobox contributors
#
# distrobox is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 3
# as published by the Free Software Foundation.
#
# distrobox is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with distrobox; if not, see <http://www.gnu.org/licenses/>.

# POSIX
#
default_input_file="./distrobox.ini"
delete=-1
distrobox_path="$(dirname "${0}")"
dryrun=0
input_file=""
replace=0
# tmpfile will be used as a little buffer to pass variables without messing up
# quoting and escaping
tmpfile="$(mktemp -u)"
verbose=0
version="1.5.0.2"
# initializing block of variables used in the manifest
additional_flags=""
additional_packages=""
entry=""
home=""
image=""
init=""
init_hooks=""
nvidia=""
pre_init_hooks=""
pull=""
root=""
start_now=""
unshare_ipc=""
unshare_netns=""
volume=""

# Cleanup tmpfiles on exit
trap 'rm -f ${tmpfile}' EXIT

# Despite of running this script via SUDO/DOAS being not supported (the
# script itself will call the appropriate tool when necessary), we still want
# to allow people to run it as root, logged in in a shell, and create rootful
# containers.
#
# SUDO_USER is a variable set by SUDO and can be used to check whether the script was called by it. Same thing for DOAS_USER, set by DOAS.
if [ -n "${SUDO_USER}" ] || [ -n "${DOAS_USER}" ]; then
	printf >&2 "Running %s via SUDO/DOAS is not supported." "$(basename "${0}")"
	printf >&2 "Instead, please try using root=true property in the distrobox.ini file.\n"
	exit 1
fi

# Print usage to stdout.
# Arguments:
#   None
# Outputs:
#   print usage with examples.
show_help() {
	cat << EOF
distrobox version: ${version}

Usage:

	distrobox assemble create
	distrobox assemble rm
	distrobox assemble create --file /path/to/file.ini
	distrobox assemble rm --file /path/to/file.ini
	distrobox assemble create --replace --file /path/to/file.ini

Options:

	--file:			path to the distrobox manifest/ini file
	--replace/-R:		replace already existing distroboxes with matching names
	--dry-run/-d:		only print the container manager command generated
	--verbose/-v:		show more verbosity
	--version/-V:		show version
EOF
}

# Parse arguments
while :; do
	case $1 in
		create)
			delete=0
			shift
			;;
		rm)
			delete=1
			shift
			;;
		--file)
			# Call a "show_help" function to display a synopsis, then exit.
			if [ -n "$2" ]; then
				input_file="${2}"
				shift
				shift
			fi
			;;
		-h | --help)
			# Call a "show_help" function to display a synopsis, then exit.
			show_help
			exit 0
			;;
		-d | --dry-run)
			shift
			dryrun=1
			;;
		-v | --verbose)
			verbose=1
			shift
			;;
		-R | --replace)
			replace=1
			shift
			;;
		-V | --version)
			printf "distrobox: %s\n" "${version}"
			exit 0
			;;
		--) # End of all options.
			shift
			break
			;;
		-*) # Invalid options.
			printf >&2 "ERROR: Invalid flag '%s'\n\n" "$1"
			show_help
			exit 1
			;;
		*) # Default case: If no more options then break out of the loop.
			# If we have a flagless option and container_name is not specified
			# then let's accept argument as container_name
			if [ -n "$1" ]; then
				input_file="$1"
				shift
			else
				break
			fi
			;;
	esac
done

set -o errexit
set -o nounset
# set verbosity
if [ "${verbose}" -ne 0 ]; then
	set -o xtrace
fi

# check if we're getting the right inputs
if [ "${delete}" -eq -1 ]; then
	printf >&2 "Please specify create or rm.\n"
	show_help
	exit 1
fi

# Fallback to distrobox.ini if no file is passed
if [ -z "${input_file}" ]; then
	input_file="${default_input_file}"
fi

# Check if file effectively exists
if [ ! -e "${input_file}" ]; then
	printf >&2 "File %s does not exist.\n" "${input_file}"
	exit 1
fi

# Create distrobox with parameters parsed from ini file.
# Arguments:
#   name of the distrobox.
# Outputs:
#   execution of the proper distrobox-create command.
run_distrobox() (
	name="${1}"

	# Source the current block variables
	if [ -e "${tmpfile}" ]; then
		# shellcheck disable=SC1090
		. "${tmpfile}" && rm -f "${tmpfile}"
	fi

	# We're going to delete, not create!
	if [ "${delete}" -ne 0 ] || [ "${replace}" -ne 0 ]; then
		printf " - Deleting %s... \n" "${name}"

		# Execute the distrobox-create command
		if [ "${dryrun}" -eq 0 ]; then
			"${distrobox_path}"/distrobox rm -f "${name}" > /dev/null || :
		fi

		# In case we're just deleting, return
		if [ "${delete}" -ne 0 ]; then
			return
		fi
	fi

	# We're going to create!
	printf " - Creating %s... \n" "${name}"

	# If distrobox already exist, and we have replace enabled, destroy the container
	# we have to recreate it.
	if "${distrobox_path}"/distrobox-list | grep -qw "${name}"; then
		printf >&2 "%s already exists\n" "${name}"
		return 0
	fi

	# Now we dynamically generate the distrobox-create command based on the
	# declared flags.
	result_command="${distrobox_path}/distrobox-create --yes"
	if [ "${verbose}" -ne 0 ]; then
		result_command="${result_command} -v"
	fi
	if [ -n "${name}" ]; then
		result_command="${result_command} --name $(sanitize_variable "${name}")"
	fi
	if [ -n "${image}" ]; then
		result_command="${result_command} --image $(sanitize_variable "${image}")"
	fi
	if [ -n "${init}" ] && [ "${init}" -eq 1 ]; then
		result_command="${result_command} --init"
	fi
	if [ -n "${root}" ] && [ "${root}" -eq 1 ]; then
		result_command="${result_command} --root"
	fi
	if [ -n "${pull}" ] && [ "${pull}" -eq 1 ]; then
		result_command="${result_command} --pull"
	fi
	if [ -n "${entry}" ] && [ "${entry}" -eq 0 ]; then
		result_command="${result_command} --no-entry"
	fi
	if [ -n "${nvidia}" ] && [ "${nvidia}" -eq 1 ]; then
		result_command="${result_command} --nvidia"
	fi
	if [ -n "${unshare_netns}" ] && [ "${unshare_netns}" -eq 1 ]; then
		result_command="${result_command} --unshare-netns"
	fi
	if [ -n "${unshare_ipc}" ] && [ "${unshare_ipc}" -eq 1 ]; then
		result_command="${result_command} --unshare-ipc"
	fi
	if [ -n "${home}" ]; then
		result_command="${result_command} --home $(sanitize_variable "${home}")"
	fi
	if [ -n "${init_hooks}" ]; then
		IFS="|"
		args=":"
		for arg in ${init_hooks}; do
			args="${args} && ${arg}"
		done
		result_command="${result_command} --init-hooks $(sanitize_variable "${args}")"
	fi
	# Replicable flags
	if [ -n "${pre_init_hooks}" ]; then
		IFS="|"
		args=":"
		for arg in ${pre_init_hooks}; do
			args="${args} && ${arg}"
		done
		result_command="${result_command} --pre-init-hooks $(sanitize_variable "${args}")"
	fi
	if [ -n "${additional_packages}" ]; then
		IFS="|"
		for packages in ${additional_packages}; do
			result_command="${result_command} --additional-packages $(sanitize_variable "${packages}")"
		done
	fi
	if [ -n "${volume}" ]; then
		IFS="|"
		for vol in ${volume}; do
			result_command="${result_command} --volume $(sanitize_variable "${vol}")"
		done
	fi
	if [ -n "${additional_flags}" ]; then
		IFS="|"
		for flag in ${additional_flags}; do
			result_command="${result_command} --additional-flags $(sanitize_variable "${flag}")"
		done
	fi

	# Execute the distrobox-create command
	if [ "${dryrun}" -ne 0 ]; then
		echo "${result_command}"
		return
	fi
	eval "${result_command}"

	# If we need to start immediately, do it, so that the container
	# is ready to be entered.
	if [ -n "${start_now}" ] && [ "${start_now}" -eq 1 ]; then
		"${distrobox_path}"/distrobox enter "${name}" -- touch /dev/null
	fi
)

# Sanitize an input, add single/double quotes and escapes
# Arguments:
#   a value string
# Outputs:
#   a value string sanitized
sanitize_variable() (
	variable="${1}"

	# If there are spaces but no quotes, let's add them
	if echo "${variable}" | grep -q " " &&
		! echo "${variable}" | grep -Eq "^'|^\""; then

		variable="\"${variable}\""
	fi

	# Return
	echo "${variable}"
)

# Parse input file and call distrobox-create accordingly
# Arguments:
#   path of the manifest file to parse
# Outputs:
#   None
parse_file() (
	file="${1}"
	name=""

	IFS='
	'
	# shellcheck disable=SC2013
	for line in $(cat "${file}"); do
		if [ -z "${line}" ]; then
			# blank line, skip
			continue
		fi
		# Remove comments and trailing spaces
		line="$(echo "${line}" | sed 's/#.*//g' | sed 's/\s*$//g')"

		# Detect start of new section
		if [ "$(echo "${line}" | cut -c 1)" = '[' ]; then
			# We're starting a new section
			if [ -n "${name}" ]; then
				# We've finished the previous section, so this is the time to
				# perform the distrobox command, before going to the new section.
				run_distrobox "${name}"
			fi

			# Remove brackets and spaces
			name="$(echo "${line}" | tr -d '][ ')"
			continue
		fi

		# Get key-values from the file
		key="$(echo "${line}" | cut -d'=' -f1 | tr -d ' ')"
		value="$(echo "${line}" | cut -d'=' -f2-)"

		# Normalize true|false to 0|1
		[ "${value}" = "true" ] && value=1
		[ "${value}" = "false" ] && value=0

		# Sanitize value, by whitespaces, quotes and escapes
		value="$(sanitize_variable "${value}")"

		# Save options to tempfile, to source it later
		touch "${tmpfile}"
		if [ -n "${key}" ] && [ -n "${value}" ]; then
			if grep -q "${key}" "${tmpfile}"; then
				value="$(echo "${value}" | sed "s|\"|\" \${${key}} |")"
			fi
			echo "${key}=${value}" >> "${tmpfile}"
		fi
	done
	#	# Execute now one last time for the last block
	run_distrobox "${name}"
)

# Exec
parse_file "${input_file}"