#!/usr/bin/env bash

set -eu

die() { echo $1 1>&2; exit 1; }
usage() { echo "USAGE: $SCRIPT NAME SERVICE [JOURNALCTL_OPTIONS...]"; exit 0; }

SCRIPT=${0##*/}
[ $# -lt 2 ] && usage

case "$1" in
  --help|-h)
    usage
  ;;
  *)
    CONTAINER=$1; shift
    SERVICE=$1; shift
  ;;
esac

CONTAINER_PATH="/lxc/$CONTAINER"

[ $EUID -eq 0 ] || die "Needs root permission"
[ -d "$CONTAINER_PATH" ] || die "No such container found: $CONTAINER"

CGROUP="/system.slice/system-lxc.slice/lxc@${CONTAINER}.service/system.slice/${SERVICE}.service"
UNIT=lxc@${CONTAINER}.service
journalctl --system _SYSTEMD_CGROUP=${CGROUP} + SYSLOG_IDENTIFIER=${SERVICE} _SYSTEMD_UNIT=${UNIT} "$@"