Reload NGINX Docker container after certbot renewal on host

01-nginx-docker.sh

#!/bin/bash
# Path: /etc/letsencrypt/renewal-hooks/deploy/01-nginx-docker.sh

###                                                                                           ##
# Inspired by: https://solariz.de/posts/20/letsencrypt_auto_nginx_reload_on_renew_doing_it_ri/ #
###                                                                                           ##


set -euo pipefail
# set -x # Just for debugging


# Is docker running?
if $(systemctl is-active --quiet docker)
then
        # Create temporary file for output
        TMP=$(mktemp /tmp/docker-nginx-test-result.XXXXXXXXXX) || { echo "Failed to create temp file"; exit 1; }

        # Test nginx confiuration
        docker exec nginx /usr/sbin/nginx -t 1>>${TMP} 2>>${TMP}

        if $(grep -q "test is successful" $TMP)
        then
                echo "NGINX config test successful, reloading..."
                docker exec nginx /usr/sbin/nginx -s reload
        else
                echo "Error: NGINX config test is unsuccessful!"
        fi

        rm -f ${TMP}
else
        echo "Docker is not running, therefore the NGINX container won't reload its config."
fi