API Monitoring with Grafana, Loki, Promtail, and Prometheus

Table of Contents

• About
• Getting Started
  • Prerequisites
  • Installation
• How It Works
• Usage

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About

This project demonstrates how to monitor monolithic APIs using Grafana, Loki, Promtail, and Prometheus.

Dashboard Previews

Dashboards Used:

• JVM Micrometer
• Spring Boot Observability

To use these dashboards, import them into Grafana and assign the required data sources (Prometheus/Loki).

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Getting Started

Prerequisites

Ensure the following software is installed:

• Docker Desktop

Installation

1. Start all services using Docker Compose:

   docker compose up -d

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Usage

After starting the services, access them via these URLs:

• API: http://localhost:8080
• Prometheus: http://localhost:9090
• Promtail: http://localhost:9080
• Grafana: http://localhost:3000

API Log Endpoints

Test logging by triggering these endpoints:

• GET /api/v1/logs/info - Generates an info log
• GET /api/v1/logs/error - Generates an error log
• GET /api/v1/logs/warning - Generates a warning log

Logs are sent to Loki and visualized in Grafana.

How It Works

Spring Boot Actuator generates the required metrics and exposes them via endpoints using HATEOAS links. Micrometer acts as a facade for Prometheus, which collects these metrics. Grafana then visualizes them. Logs are sent to Loki via Promtail for further analysis.

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