common/systemd

##/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2024 Oracle.  All Rights Reserved.
#
# Routines for managing systemd units

# Is systemd installed?
_systemd_installed() {
	_have_program systemctl
}

_require_systemd_installed() {
	_require_program systemctl systemd
}

# Is systemd running on this system?
_systemd_is_running() {
	_systemd_installed || return 1
	systemctl show-environment &>/dev/null
}

_require_systemd_is_running() {
	_systemd_is_running || \
		_notrun "systemd is not active"
}

# Is this unit defined, as according to systemd?
_systemd_unit_defined() {
	_systemd_installed || return 1
	systemctl cat "$1" >/dev/null
}

_require_systemd_unit_defined() {
	_require_systemd_installed
	_systemd_unit_defined "$1" || \
		_notrun "systemd unit \"$1\" not found"
}

# Is this unit active, as according to systemd?
_systemd_unit_active() {
	_systemd_installed || return 1
	_systemd_unit_defined "$1" || return 1

	test "$(systemctl is-active "$1")" = "active"
}

# Wait for up to a certain number of seconds for a service to reach inactive
# state.
_systemd_unit_wait() {
	local svcname="$1"
	local timeout="${2:-30}"

	for ((i = 0; i < (timeout * 2); i++)); do
		test "$(systemctl is-active "$svcname")" = "inactive" && break
		sleep 0.5
	done
}

_require_systemd_unit_active() {
	_require_systemd_unit_defined "$1"
	_systemd_unit_active "$1" || \
		_notrun "systemd unit \"$1\" not active"
}

# Find the path to a systemd unit
_systemd_unit_path() {
	systemctl show "$1" | grep FragmentPath= | cut -d '=' -f 2
}

# Make systemd reload itself after changing unit files or generator sources
# such as /etc/fstab
_systemd_reload() {
	systemctl daemon-reload
}

# Where is the systemd runtime directory?
_systemd_runtime_dir() {
	echo "/run/systemd/system/"
}

# What is the status of this systemd unit?
_systemd_unit_status() {
	_systemd_installed || return 1
	systemctl status "$1"
}

# Start a running systemd unit
_systemd_unit_start() {
	systemctl start "$1"
}
# Stop a running systemd unit
_systemd_unit_stop() {
	systemctl stop "$1"
}

# Mask or unmask a running systemd unit
_systemd_unit_mask() {
	systemctl mask "$1"
}
_systemd_unit_unmask() {
	systemctl unmask "$1"
}
_systemd_unit_masked() {
	systemctl status "$1" 2>/dev/null | grep -q 'Loaded: masked'
}

_systemd_service_unit_path() {
	local template="$1"
	local path="$2"

	systemd-escape --template "$template" --path "$path"
}