Blackbox Exporter by Prometheus
TCP Checks, host: test.mydomain.com, port: 443
curl https://blackbox-exporter.mydomain.com/probe?target=test.mydomain.com:443&module=tcp_connect&debug=true
HTTP Check: https://test.mydomain.com
curl https://blackbox-exporter.mydomain.com/probe?target=https://test.mydomain.com&module=http_2xx&debug=true
SSH Check: test.mydomain.com:22
curl "https://blackbox-exporter.mydomain.com/probe?target=test.mydomain.com:22&module=ssh_banner&debug=true"