#!/bin/bash

# Recommended crontab:
#   * *   *   *   *    /path/to/collect-certdata.sh

influx_host="{{ influx_host }}"
influx_path="/api/v2/write"
influx_org="{{ influx_org }}"
influx_bucket="{{ influx_bucket }}"
influx_token="{{ influx_token }}"
influx_metric="certificate"
domains=({% for dns in certificate_monitor_domains %}"{{dns}}" {% endfor %})

influx_url="${influx_host}${influx_path}?org=${influx_org}&bucket=${influx_bucket}"
influx_header_auth="Authorization: Token ${influx_token}"
influx_header_content="Content-Type: text/plain; charset=utf-8"
influx_header_accept="Accept: application/json"

for dn in ${domains[@]}; do
 certificate="$(openssl s_client -connect ${dn}:443 2>/dev/null </dev/null | openssl x509)"

 # Calculation broken down from https://gist.github.com/holly/4205943
 datestr=`echo "${certificate}" | openssl x509  -enddate -noout | cut -d'=' -f2`
 daystr=`date -d "$datestr" "+%s"`
 current_time=$(date "+%s")
 days=`echo $((($daystr - $current_time) / 60 / 60 / 24))`

 data="${influx_metric},domain=${dn} remaining=${days}i"

 curl --request POST "${influx_url}" --header "${influx_header_auth}" --header "${influx_header_content}" --header "${influx_header_accept}" --data-binary "${data}"

done