watchman/watchman.bash

#!@BASH_PATH@

# Config
watchman_version='@VERSION@'

# Functions
watchman.usage() {
	while read -r; do printf '%s\n' "$REPLY"; done <<- EOF
		Usage: watchman [flags] <service> <action>
		Flags:
		    -h, --help      Show this message.
		    -v, --version   Show watchman's version.
		    -d, --verbose   Verbose output.
	EOF
}

watchman.msg() { printf '%s\n' "[watchman] $1"; }
watchman.err() { watchman.msg "(error) $1"; }
watchman.debug() {
	[[ "$flag_verbose" ]] && {
		watchman.msg "{v} $1"
	}
}

watchman.init() {
	# Check if XDG_ stuff is set
	XDG_RUNTIME_DIR=${XDG_RUNTIME_DIR:-"/run/user/$UID"}
	XDG_CONFIG_HOME=${XDG_CONFIG_HOME:-"$HOME/.config"}

	# Check if the user is root.
	if (( UID )); then
		cfg_dir="@CFGDIR_USER@"
		cfg_rundir="@RUNDIR_USER@"
		cfg_logdir="@LOGDIR_USER@"
	else
		cfg_dir="@CFGDIR@"
		cfg_rundir="@RUNDIR@"
		cfg_logdir="@LOGDIR@"
	fi

	[[ -f "${cfg_dir}/watchman.conf" ]] && {
		source "${cfg_dir}/watchman.conf" || {
			watchman.err "Failed to source config: ${cfg_dir}/watchman.conf. Fix it to proceed."
			return 1
		}
	}
	
	cfg_initdir="${cfg_dir}/init.d"
	cfg_init_dirs+=( "$cfg_dir"/{init.d,conf.d} "$cfg_rundir" "$cfg_logdir" )

	for i in "${cfg_init_dirs[@]}"; do
		[[ -e "$i" ]] || {
			watchman.debug "$i does not exist, creating..."
			mkdir -p "$i" || {
				watchman.err "Can't create $i!"
				return 1
			}
		}
	done

	return 0
}

watchman.done() {
	>"$cfg_rundir/${service_name}.done" || {
		watchman.msg "Warning! Can't mark ${service_name} as enabled."
	}
}

watchman.spawn() {
	[[ "$service_command" ]] || {
		watchman.err "Please specify what to run with \$service_command"
	}

	if [[ "$service_respawn" == 'true' ]]; then
		[[ "$service_type" == 'oneshot' ]] && {
			watchman.err "A oneshot service can not be respawned. Choose one or the other."
			return 1
		}

		if [[ "${service_pidfile}" ]]; then
			watchman.err "Respawning forking services is not supported!"
			return 1
		fi

		watchman-svc -p "$service_pidfile_int" -l "$service_logfile" -r "$service_command" "${service_args[@]}"
	else
		if [[ "$service_type" == 'oneshot' ]]; then
			"${service_command}" "${service_args[@]}" 1>>"$service_logfile" 2>>"$service_logfile"  || { return 1; }
		else
			watchman-svc -p "$service_pidfile_int" -l "$service_logfile" "$service_command" "${service_args[@]}"
		fi
	fi
}

watchman.tempfiles() {
	# Create temporary files
	for f in "${service_tmpfiles[@]}"; do
		IFS=':' read -r f_path f_type f_args <<< "$f"

		if ! [[ -e $f_path ]]; then
			case "$f_type" in
				symlink)
					f_target=$f_args
					ln -s "$f_target" "$f_path"
				;;

				file|dir)
					IFS=':' read -r f_perms f_owner f_group <<< "$f_args"

					if [[ $f_type == 'file' ]]; then
						> "$f_path"
						chmod "${f_perms:-644}" "$f_path"
					else
						mkdir -p -m "${f_perms:-755}" "$f_path"
					fi

					if [[ "$f_owner" || "$f_group" ]]; then
						chown "${f_owner:-root}:${f_group:-root}" "$f_path"
					fi
				;;
			esac
		fi
	done
}

watchman.start() {
	local try

	watchman.status && {
		if [[ "$service_type" == 'oneshot' ]]; then
			watchman.err "$service_name is already enabled"
		else
			watchman.err "$service_name is already running"
		fi

		return 0
	}

	# Start dependencies
	for d in "${service_depends[@]}"; do
		IFS=':' read -r d_name d_type <<< "$d"

		"$0" "$d_name" start || {
			err "Failed to start service dependency: $d_name"

			if ! [[ $d_type == 'soft' ]]; then
				return 1
			fi
		}
	done

	# pre-start
	run_if_function pre_start || { return $?; }

	[[ "$service_workdir" ]] && { cd "$service_workdir"; }

	>"$service_logfile" 2>/dev/null || {
		watchman.msg "Warning! Logfile is not writeable! Defaulting to /dev/null"
		service_logfile='/dev/null'
	}

	watchman.tempfiles

	spawn 1>>"$service_logfile" 2>>"$service_logfile"
	spawn_result="$?"
		
	case "$service_type" in
		(oneshot)
			(( spawn_result )) && {
				watchman.err "Failed to enable ${service_name}!"
				return 1
			}

			watchman.done
			watchman.msg "$service_name enabled"
		;;

		(*)
			if [[ "$service_pidfile" ]]; then
				if [[ ! -f "$service_pidfile" ]]; then
					watchman.msg "Making sure the process had time to wite its pidfile..."
					try=0; while [[ ! -f "$service_pidfile" && "$try" -lt "${service_spawn_delay:-3}" ]]; do
						((try++))
						sleep 1
					done
				fi

				if ! [[ -f "$service_pidfile" ]]; then
					return 3
				fi
			fi

			watchman.msg "$service_name started"

			run_if_function post_start || { return $?; }
		;;
	esac
}

watchman.depends() {
	[[ "$action" == 'start' ]] || { return 0; }

	for s in "$@"; do
		"$0" "$s" status || {
			watchman.msg "Starting ${s} as ${service_name} depends on it."
			"$0" "$s" start || {
				watchman.err "Starting $s failed, aborting."
				return 31
			}
		}
	done

	return 0
}

watchman.pid_check() { kill -0 "$1" 2>/dev/null; }

watchman.pid_wait() {
	counter='0'
	printf "[watchman] Waiting for PID to exit: %s..." "$1"

	while watchman.pid_check "$1"; do
		((counter++))

		[[ "$counter" -ge "${service_stop_timeout:-30}" ]] && {
			printf 'timeout\n'
			return 1
		}

		sleep 1
		printf '.'
	done

	printf '\n'

	return 0
}

watchman.stop() {
	watchman.status || {
		watchman.err "$service_name doesn't seem to be running"
		return 1
	}

	run_if_function pre_stop || { return $?; }

	case "$service_type" in
		(oneshot)
			watchman.msg "Removing $cfg_rundir/${service_name}.done file..."
			rm "$cfg_rundir/${service_name}.done"
		;;

		(*)
			kill "$service_pid"

			watchman.pid_wait "$service_pid" || { return 3; }

			rm -f "$service_pidfile" || {
				watchman.err "Failed to remove pidfile: $service_pidfile"
			}
		;;
	esac

	run_if_function post_stop || { return $?; }
}

watchman.status() {
	case "$service_type" in
		(oneshot)
			if [[ -e "$cfg_rundir/${service_name}.done" ]]; then
				return 0
			fi
		;;

		(*)
			if [[ "$service_pid" ]]; then
				if kill -0 "$service_pid" &>/dev/null; then
					return 0
				fi
			fi
		;;
	esac

	return 1
}

watchman.service_usage() {
	local valid_actions

	for i in "${service_actions[@]}"; do
		if is_function "$i"; then
			valid_actions+="$i|";
		fi
	done

	watchman.msg "Usage: $service_name <${valid_actions%|*}>"
}

watchman.service_get_pid() {
	local _pid

	if [[ "$service_pidfile" ]]; then
		if [[ -f "$service_pidfile" ]]; then
			_pid=$(<"$service_pidfile")
		fi
	else
		if [[ -f "$service_pidfile_int" ]]; then
			_pid=$(<"$service_pidfile_int")
		fi
	fi

	printf '%s' "$_pid"
}

watchman.reload() {
	watchman.status || {
		watchman.err "$service_name is not running"
		return 1
	}

	watchman.msg "Reloading ${service_name}..."
	kill -1 "$service_pid" 
}

watchman.logs() {
	if [[ -f "$service_logfile" ]]; then
		watchman.msg "Output for ${service_name}:"
		while read -r; do
			printf '%s\n' "$REPLY"
		done < "$service_logfile"
	else
		watchman.err "No log available for ${service_name}"
	fi

	if [[ "$service_respawn" == 'true' ]]; then
		if [[ -f "$cfg_logdir/${service_name}_respawn.log" ]]; then
			watchman.msg "Output for ${service_name} (watchdog):"
			while read -r; do
				printf '%s\n' "$REPLY"
			done < "$cfg_logdir/${service_name}_respawn.log"
		fi
	fi
}

watchman.edit() {
	if ! [[ "$EDITOR" ]]; then
		EDITOR='vim'
	fi

	"$EDITOR" "$service_script"
}

watchman.args() {
	while [[ "$1" ]]; do
		case "$1" in
			(-h) watchman.usage; exit;;
			(-d) flag_verbose='1';;
			(-v) printf '%s\n' "$watchman_version"; exit;;

			(--) shift; break;;

			(-*)
				watchman.err "Invalid key: $1"
				watchman.usage
				return 1
			;;

			(*) args+=( "$1" );;
		esac; shift
	done
}

nullerr() {
	"$@" 2>/dev/null
}

is_variable() {
	declare param_args param=$1

	read -r _ param_args _ <<< $( nullerr declare -p "$param" )

	if (( $? )); then
		return 1
	fi

	if [[ "$param_args" == '--' ]]; then
		return 0
	fi

	return 1
}

is_function() {
	declare word=$1 word_type

	word_type=$( type -t "$word" )

	if [[ $word_type == 'function' ]]; then
		return 0
	fi

	return 1
}

run_if_function() {
	declare func=$1; shift

	if is_function "$func"; then
		"$func" "$@"
	fi

	return 0
}

spawn() { watchman.spawn; }

start() { watchman.start; }
stop() { watchman.stop; }
restart() { stop; start; }
reload() { watchman.reload; }
edit() { watchman.edit; }

status() {
	local service_status

	watchman.status && {
		service_status='running'
	}

	if [[ "$service_status" ]]; then
		[[ "$service_type" == 'oneshot' ]] && {
			watchman.msg "$service_name is enabled"
		} || {
			watchman.msg "$service_name is running ($service_pid)"
		}

		return 0
	else
		watchman.msg "$service_name is down"
	fi

	return 1
}

logs() { watchman.logs; }

depends() { watchman.depends "$@"; }

watchman.main() {
	# Parse arguments
	watchman.args "$@" || { return "$?"; }
	set -- "${args[@]}"

	watchman.init "$@" || { return "$?"; }

	# Exit on no arguments
	(( $# )) || {
		watchman.usage
		return 9
	}

	# Set default service actions.
	service_actions=( 'start' 'stop' 'restart' 'reload' 'status' )
	
	# Set $action and exit immediately if it's not set.
	action="$2"
	[[ "$action" ]] || {
		watchman.err 'Syntax error: no action specified.'
		watchman.service_usage
		return 1
	}
	
	# Basename for poor people.
	service_name="${1##*/}"

	# Check if the first argument is an existing file,
	# set $service_script to it if it is. Otherwise, search
	# for the service in the initdir.
	if [[ -f "$1" ]]; then
		service_script="$1"
	else
		if [[ -f "${cfg_initdir}/${service_name}" ]]; then
			service_script="${cfg_initdir}/${service_name}"
		else
			watchman.err "$service_name doesn't exist in $cfg_initdir"
			return 1
		fi
	fi

	# Source the script
	source "$service_script" || { return 13; }
	
	# check if the command exists and is an executable file.
	[[ "$service_command" ]] && {
		[[ -e "${service_command}" ]] || {
			watchman.err "Service command for ${service_name} is set but does not exist: ${service_command}"
			return 1
		}

		[[ -f "${service_command}" ]] || {
			watchman.err "Service command for ${service_name} is set but is not a file: ${service_command}"
			return 1
		}

		[[ -x "${service_command}" ]] || {
			watchman.err "Service command for ${service_name} is set but is not executable: ${service_command}"
			return 1
		}
	}
	
	# Source the additional service configuration if that exists.
	[[ -f "${cfg_dir}/conf.d/${service_name}.sh" ]] && {
		source "${cfg_dir}/conf.d/${service_name}.sh" || {
			return $?
		}
	}

	# If $service_args is a variable, convert it into an array
	if is_variable service_args; then
		watchman.err "\$service_args for the $service_name service is a variable."
		watchman.err "Since watchman 1.11.1, \$service_args is supposed to be an array."
		watchman.err "Please fix it in the service definition."

		read -r -a service_args <<< "$service_args"
	fi

	# Set default service_logfile and internal pidfile
	# These need to be here so that services behave as expected if $service_name is explicitly set.
	[[ "$service_logfile" ]] || { service_logfile="$cfg_logdir/${service_name}.log"; }
	service_pidfile_int="$cfg_rundir/${service_name}.pid" # Does not need to be reassignable. Seriously. Don't.

	# Try to get the service's pid.
	service_pid="$(watchman.service_get_pid)"

	# If the action is defined, do it. If not, fail gracefully.
	if is_function "$action"; then
		"$action"

		action_rcode="$?"
		(( action_rcode > 1 )) && {
			watchman.err "Function $action failed for ${service_name}."
		}

		return "$action_rcode"
	else
		watchman.err "Function $action is not defined for ${service_name}."
		return 17
	fi
}

# Main
watchman.main "$@"