#!/bin/bash
# I, Ian Kelling, follow the GNU license recommendations at
# https://www.gnu.org/licenses/license-recommendations.en.html. They
# recommend that small programs, < 300 lines, be licensed under the
# Apache License 2.0. This file contains or is part of one or more small
# programs. If a small program grows beyond 300 lines, I plan to switch
# its license to GPL.

# Copyright 2024 Ian Kelling

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


# usage: since this is a counter, in prometheus alert manager you will
# need to test something like: rate(node_systemd_unit_result_fail_count[30m]) > 0

source /a/bin/bash-bear-trap/bash-bear
[[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"

ser_name=$1

mkdir -p /var/lib/prometheus/node-exporter

f=/var/local/sysd-prom-fail/${ser_name}-result.prom


if [[ ! -s $f ]]; then
  SERVICE_RESULT=success /usr/local/bin/sysd-prom-fail $ser_name
fi

tmp=$(mktemp)

cat >>$tmp <<EOF
[Service]
ExecStopPost=+/usr/local/bin/sysd-prom-fail $ser_name
EOF

dir=/etc/systemd/system/$ser_name.service.d
mkdir -p $dir
out=$(rsync -cipgo --chmod=644 --chown=root:root $tmp $dir/sysd-prom-fail.conf)
if [[ $out ]]; then
  echo $0: systemctl daemon-reload
  systemctl daemon-reload
  if systemctl is-active $ser_name &>/dev/null; then
    echo $0: systemctl restart $ser_name
    systemctl restart $ser_name ||:
  fi
fi

# todo: make uninstall script