healthchecks-client

#!/usr/bin/env bash
# Copyright (C) 2021 Rodrigo Silva (MestreLion) <linux@rodrigosilva.com>
# License: GPLv3 or later. See <http://www.gnu.org/licenses/gpl.html>
# -----------------------------------------------------------------------------

DESCRIPTION='SmartCronHelper, a healthchecks.io client'
ARGS='API_KEY [API_URL] [SOURCE] [USER]'

setuplib=${SETUP_LIB_PATH:-"$(dirname "$(readlink -f "$0")")"/../setuplib}
# shellcheck source=../setuplib
if [[ -r "$setuplib" ]]; then source "$setuplib"; else
	echo "Setup library not found: $setuplib" >&2; exit 1;
fi

# -----------------------------------------------------------------------------

api_key=${1:-${SETUP_HEALTHCHECKS_API_KEY:-}}; argument "$api_key" API_KEY
api_url=${2:-${SETUP_HEALTHCHECKS_API_URL:-"https://healthchecks.io/api/v1/"}}
source=${3:-${SETUP_HEALTHCHECKS_SOURCE:-"sch"}}
group=${4:-${SETUP_HEALTHCHECKS_GROUP:-"monitor"}}

path=/usr/local/lib/sch
bin=${path}/bin/sch
target=/usr/local/bin/sch

# -----------------------------------------------------------------------------

message "Install dependencies"
install_package git python3-{pip,venv}

message "Install environment at $path"
setup_run sudo -H python3 -m venv -- "$path"
setup_run sudo -H "$path"/bin/pip install --upgrade pip wheel

message "Install client $source"
setup_run sudo -H "$path"/bin/pip install --upgrade "$source"

message "Install executable $target"
setup_run sudo ln -fs -- "$bin" "$target"

message "Create system group $group and add yourself to it"
setup_run sudo addgroup --system --quiet -- "$group"
setup_run sudo adduser -- "$USER" "$group"

config=/etc/sch.conf
message "Create config file $config"
cat <<-EOF | setup_run sudo -u root -g "$group" tee -- "$config"
	[hc]
	healthchecks_api_url = ${api_url}
	healthchecks_api_key = ${api_key}
	force_ipv4 = 1

	[sch]
	loglevel = WARNING
EOF
setup_run sudo_for "$config" chmod 640 -- "$config"

message "To enable monitoring jobs, add to 'crontab -e' or /etc/cron.d:"
cat <<-EOF
	# MUST be absolute path, even if it's in \$PATH!
	SHELL=$(escape "$target")

	# Job description (will be parsed)
	* * * * *  JOB_ID=foobar  cmd args...  # inline comments also parsed!
EOF