Server Health API

A lightweight Go application for comprehensive server health monitoring. This tool checks the health of various services, ports, and endpoints on a server, making it ideal for verifying server readiness before performing maintenance operations.

Developed by Digitalis.IO

Features

• Service Health Checks: Monitor systemd services status with validation
• Port Availability: Verify TCP port accessibility (IPv4 and IPv6 support)
• HTTP/HTTPS Endpoint Monitoring: Check endpoint availability and response codes
• Flexible Status Validation: Support for single or multiple acceptable status codes
• Security Features:
  • Basic authentication with constant-time comparison
  • SSL/TLS support for the API server
  • Configurable SSL verification for monitored endpoints
• Production Ready:
  • Graceful shutdown handling (SIGINT/SIGTERM)
  • HTTP client timeout configuration
  • Connection pooling and reuse
  • Thread-safe concurrent request handling
  • Input validation and sanitization
• Configuration: Flexible YAML configuration with environment variable overrides

Configuration

The application is configured using a config.yaml file. Below is an example configuration:

config:
  listen:
    host: "0.0.0.0"
    port: 8080
  ssl:
    enabled: false
    certFile: "path/to/certfile"
    keyFile: "path/to/keyfile"
  auth:
    enabled: false
    username: "user"
    password: "pass"
services:
  - name: "nginx"
    status: "active"
ports:
  - name: "HTTP"
    address: "127.0.0.1"
    port: 80
endpoints:
  - name: "Google"
    url: "https://www.google.com"
    status: 200
    # alternatively, use a list
    #statuses: [200, 301]

Running the Application

Using Go

1. Build the application:

   make build

2. Run the application:

   make run

Using Docker

1. Build the Docker image:

   docker build -t server-health-api .

2. Run the Docker container:

   docker run -p 8080:8080 -e HEALTH_LISTEN_HOST="0.0.0.0" -e HEALTH_LISTEN_PORT="8080" server-health-api

API Endpoint

The application exposes a single endpoint:

• GET /healthy: Checks the health of the configured services, ports, and endpoints. Returns a JSON response with the status and messages.

Example response:

{
  "status": "Server is healthy",
  "messages": [
    "Service Name: nginx, Status: active is as expected",
    "Port Name: HTTP, Port: 80 is available",
    "Endpoint Name: Google, URL: https://www.google.com, Status: 200 is as expected"
  ]
}

Environment Variables

• HEALTH_LISTEN_HOST: The host address to listen on (default: 0.0.0.0).
• HEALTH_LISTEN_PORT: The port to listen on (default: 8080).
• HEALTHCHECK_CONFIG_FILE: The path to the configuration file (default: config.yaml).

Command Line Options

• -config: Specify the path to the configuration file. This overrides the HEALTHCHECK_CONFIG_FILE environment variable.

License

This project is licensed under the Apache License.

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About Digitalis.IO

Digitalis.IO is a leading provider of cloud-native solutions and DevOps expertise. We specialize in helping organizations modernize their infrastructure, implement best practices, and achieve operational excellence.

Get in touch:

• Website: https://digitalis.io/
• Solutions: Cloud Architecture, Kubernetes, DevOps, SRE
• Services: Consulting, Training, Implementation

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Server Health API - Built with ❤️ by Digitalis.IO