Prometheus Metrics Server

Go application provides an HTTP server for storing and serving Prometheus metrics. The server supports four types of metrics: gauges, counters, histograms, and summaries. Metrics can be stored by sending POST requests to specific endpoints, and they can be accessed via the /metrics endpoint.

It suppose to be used in a stateless environment where you can't store metrics in memory between requests. This server will store the metrics in memory and expose them in Prometheus format.

Table of Contents

• Use Case
• Prerequisites
• Installation
• Endpoints
  • Store Gauge
  • Store Counter
  • Store Histogram
  • Store Summary
  • Metrics Endpoint
  • Accessing Metrics
• Contributing
• License

Use Case

This Prometheus Metrics Server is ideal for languages like PHP, which lack persistent memory and shared state between requests

Example

Send order metrics from a PHP e-commerce platform to the server. The server aggregates these metrics, making them available to Prometheus for real-time monitoring and alerts, ensuring efficient metrics management in stateless environments.

Prerequisites

• Go 1.22.3 or higher
• Prometheus client library for Go

Installation

1. Clone the repository:

   git clone https://github.com/synaxz/metrics-server.git
   cd metrics-server

2. Install dependencies:

   go mod tidy

3. Build the application:

   go build -o metrics-server

4. Run the application:

   ./metrics-server

Endpoints

Store Gauge

• Endpoint: /store/gauge
• Method: POST
• Payload:

  {
      "key": "gauge_metric",
      "value": 10,
      "labels": {"env": "prod"},
      "help": "Gauge metric",
      "action": "set"
  }

• Actions: set, inc, dec, add, sub
• Curl Command:

  curl -X POST -d '{
    "key": "gauge_metric",
    "value": 10,
    "labels": {"env": "prod"},
    "help": "Gauge metric",
    "action": "set"
  }' http://localhost:8080/store/gauge

Store Counter

• Endpoint: /store/counter
• Method: POST
• Payload:

  {
      "key": "counter_metric",
      "value": 1,
      "labels": {"env": "prod"},
      "help": "Counter metric",
      "action": "inc"
  }

• Actions: inc, add
• Curl Command:

  curl -X POST -d '{
    "key": "counter_metric",
    "value": 1,
    "labels": {"env": "prod"},
    "help": "Counter metric",
    "action": "inc"
  }' http://localhost:8080/store/counter

Store Histogram

• Endpoint: /store/histogram
• Method: POST
• Payload:

  {
      "key": "histogram_metric",
      "value": 10,
      "labels": {"env": "prod"},
      "help": "Histogram metric",
      "action": "observe"
  }

• Actions: observe
• Curl Command:

  curl -X POST -d '{
    "key": "histogram_metric",
    "value": 10,
    "labels": {"env": "prod"},
    "help": "Histogram metric",
    "action": "observe"
  }' http://localhost:8080/store/histogram

Store Summary

• Endpoint: /store/summary
• Method: POST
• Payload:

  {
      "key": "summary_metric",
      "value": 10,
      "labels": {"env": "prod"},
      "help": "Summary metric",
      "action": "observe"
  }

• Actions: observe
• Curl Command:

  curl -X POST -d '{
    "key": "summary_metric",
    "value": 10,
    "labels": {"env": "prod"},
    "help": "Summary metric",
    "action": "observe"
  }' http://localhost:8080/store/summary

Metrics Endpoint

• Endpoint: /metrics
• Method: GET
• Description: Returns all stored metrics in Prometheus format.

Accessing Metrics

Open your browser and navigate to http://localhost:8080/metrics to view all the stored metrics.

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

License

This project is licensed under the MIT License.