prometheus-configuration

# Prometheus Configuration

Complete guide to Prometheus setup, metric collection, scrape configuration, and recording rules.

## Purpose

Configure Prometheus for comprehensive metric collection, alerting, and monitoring of infrastructure and applications.

## When to Use

- Set up Prometheus monitoring
- Configure metric scraping
- Create recording rules
- Design alert rules
- Implement service discovery

## Prometheus Architecture

```
┌──────────────┐
│ Applications │ ← Instrumented with client libraries
└──────┬───────┘
       │ /metrics endpoint
       ↓
┌──────────────┐
│  Prometheus  │ ← Scrapes metrics periodically
│    Server    │
└──────┬───────┘
       │
       ├─→ AlertManager (alerts)
       ├─→ Grafana (visualization)
       └─→ Long-term storage (Thanos/Cortex)
```

## Installation

### Kubernetes with Helm

```bash
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update

helm install prometheus prometheus-community/kube-prometheus-stack \
  --namespace monitoring \
  --create-namespace \
  --set prometheus.prometheusSpec.retention=30d \
  --set prometheus.prometheusSpec.storageVolumeSize=50Gi
```

### Docker Compose

```yaml
version: "3.8"
services:
  prometheus:
    image: prom/prometheus:latest
    ports:
      - "9090:9090"
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
      - prometheus-data:/prometheus
    command:
      - "--config.file=/etc/prometheus/prometheus.yml"
      - "--storage.tsdb.path=/prometheus"
      - "--storage.tsdb.retention.time=30d"

volumes:
  prometheus-data:
```

## Configuration File

**prometheus.yml:**

```yaml
global:
  scrape_interval: 15s
  evaluation_interval: 15s
  external_labels:
    cluster: "production"
    region: "us-west-2"

# Alertmanager configuration
alerting:
  alertmanagers:
    - static_configs:
        - targets:
            - alertmanager:9093

# Load rules files
rule_files:
  - /etc/prometheus/rules/*.yml

# Scrape configuration