#!/bin/bash
# Copyright (C) 2019 Checkmk GmbH - License: GNU General Public License v2
# This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
# conditions defined in the file COPYING, which is part of this source code package.

# Reason for this no-op: shellcheck disable=... before the first command disables the error for the
# entire script.
:

# Disable unused variable error (needed to keep track of version)
# shellcheck disable=SC2034
CMK_VERSION="2.3.0p38"

# Check for APT updates (Debian, Ubuntu)
# TODO:
# Check programmieren:
#   * Schwellwerte auf Anzahlen
#   * Regexen auf Pakete, die zu CRIT/WARN führen

# This variable can either be "upgrade" or "dist-upgrade"
UPGRADE=upgrade
DO_UPDATE=yes

check_apt_update() {
    if [ "$DO_UPDATE" = yes ]; then
        # NOTE: Even with -qq, apt-get update can output several lines to
        # stderr, e.g.:
        #
        # W: There is no public key available for the following key IDs:
        # 1397BC53640DB551
        apt-get update -qq 2>/dev/null
    fi
    apt-get -o 'Debug::NoLocking=true' -o 'APT::Get::Show-User-Simulation-Note=false' -s -qq "$UPGRADE" | grep -v '^Conf'
}

if type apt-get >/dev/null; then
    echo '<<<apt:sep(0)>>>'
    out=$(check_apt_update)
    if [ -z "$out" ]; then
        echo "No updates pending for installation"
    else
        echo "$out"
    fi
fi