httpmon

README

HTTP Monitor

A one-shot tool for monitoring HTTP and HTTPS endpoints, designed for simplicity and integration into existing workflows.

Overview

HTTP Monitor (httpmon) is a lightweight tool for operations engineers to monitor HTTP endpoints. It checks critical metrics like response time, status, and TLS certificate validity, outputting results in CSV format to standard output (stdout). Use it with schedulers like cron for continuous monitoring.

Key Features

• Monitor single or multiple HTTP/HTTPS endpoints.
• Load targets from a file (one URL per line).
• Customize monitor names for easier identification.
• Detailed performance metrics for HTTP requests.
• Summarize monitoring results.

Quick Start

Prerequisites

• Install Go if you plan to build the tool from source.

Usage

1. Monitor one or more URLs:

   httpmon monitor [URL]...
   

2. Monitor URLs from a file (one URL per line):

   httpmon monitor -f [FILENAME]
   

3. Set a custom monitor name:

   httpmon monitor -n my-monitor [URL]...
   

4. Save results to a log file:

   httpmon monitor --csv -b [URL]... >> monitoring.log
   

5. Create summary statistics:

   cat monitoring.log | httmon summarize --csv -i
   

Currently the summarize command only support csv formatted logs.

Using with Cron for Continuous Monitoring

Schedule regular monitoring by combining httpmon with cron. For example, to run every 5 minutes and append results to monitoring.log:

*/5 * * * * /path/to/httpmon monitor --csv -b https://example.com >> /path/to/monitoring.log

Output Format

The results are printed to stdout in CSV format with the following columns:

Column Name	Description
Monitor Name	Name assigned to the monitor.
URL	The target URL being monitored.
Status	Monitoring result (e.g., success or failure).
Timestamp	Time of the check (UTC).
Status Code	HTTP status code (e.g., 200, 404).
Message	Additional status details.
DNS Time (ms)	Time spent resolving DNS.
Connection Time (ms)	Time taken to establish a connection.
TLS Time (ms)	Time spent establishing a TLS handshake.
TTFB (ms)	Time to first byte.
Download Time (ms)	Time spent downloading the response.
Total Response Time (ms)	Total time for the request.
Cert Validity (s)	Remaining validity of the TLS certificate.

Examples

1. Monitor two URLs:

   httpmon monitor https://example.com https://example.org
   

2. Monitor URLs from a file (targets.txt with one URL per line):

   httpmon monitor -f targets.txt
   

3. Monitor a URL with a custom name:

   httpmon monitor -n api-monitor https://api.example.com
   

4. Append output to a log file:

   httpmon monitor -b --csv https://example.com >> monitoring.log
   

Who Should Use This Tool?

This tool is ideal for anyone who needs a simple, one-shot utility for gathering HTTP endpoint performance data. Pair it with cron or other schedulers for continuous monitoring and logging.