Grafana/Prometheus Server Monitoring Setup for Website

Setting Up Server Monitoring with Grafana and Prometheus

Prometheus collects metrics, Grafana visualizes them. Prometheus uses a pull model: it queries exporters on a schedule. Alertmanager sends notifications to Slack, PagerDuty, email when alerts fire.

Component Stack

[Servers] → [Node Exporter] ←── [Prometheus] ←── [Alertmanager] → [Slack/PagerDuty]
[PHP-FPM] → [php-fpm_exporter]          ↓
[Nginx]   → [nginx-vts-exporter]    [Grafana]
[Redis]   → [redis_exporter]
[Postgres]→ [postgres_exporter]

Docker Compose: Complete Stack

# docker-compose.monitoring.yml
services:
  prometheus:
    image: prom/prometheus:v2.50.1
    volumes:
      - ./monitoring/prometheus.yml:/etc/prometheus/prometheus.yml
      - ./monitoring/alerts:/etc/prometheus/alerts
      - prometheus_data:/prometheus
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
      - '--storage.tsdb.retention.time=30d'
      - '--storage.tsdb.retention.size=20GB'
      - '--web.enable-lifecycle'
    ports:
      - "9090:9090"

  alertmanager:
    image: prom/alertmanager:v0.27.0
    volumes:
      - ./monitoring/alertmanager.yml:/etc/alertmanager/alertmanager.yml
    ports:
      - "9093:9093"

  grafana:
    image: grafana/grafana:10.3.0
    environment:
      GF_SECURITY_ADMIN_PASSWORD: ${GRAFANA_PASSWORD}
      GF_SERVER_ROOT_URL: https://grafana.example.com
      GF_SMTP_ENABLED: "true"
      GF_SMTP_HOST: smtp.example.com:587
    volumes:
      - grafana_data:/var/lib/grafana
      - ./monitoring/grafana/dashboards:/etc/grafana/provisioning/dashboards
      - ./monitoring/grafana/datasources:/etc/grafana/provisioning/datasources
    ports:
      - "3000:3000"

  node-exporter:
    image: prom/node-exporter:v1.7.0
    command:
      - '--path.rootfs=/host'
      - '--collector.filesystem.mount-points-exclude=^/(sys|proc|dev|host|etc)($$|/)'
    volumes:
      - /:/host:ro,rslave
    pid: host
    network_mode: host

  cadvisor:
    image: gcr.io/cadvisor/cadvisor:v0.49.1
    volumes:
      - /:/rootfs:ro
      - /var/run:/var/run:ro
      - /sys:/sys:ro
      - /var/lib/docker/:/var/lib/docker:ro
    ports:
      - "8080:8080"

volumes:
  prometheus_data:
  grafana_data:

prometheus.yml

global:
  scrape_interval: 15s
  evaluation_interval: 15s
  external_labels:
    cluster: production
    region: eu-west-1

alerting:
  alertmanagers:
    - static_configs:
        - targets: ['alertmanager:9093']

rule_files:
  - /etc/prometheus/alerts/*.yml

scrape_configs:
  - job_name: node
    static_configs:
      - targets:
          - web01:9100
          - web02:9100
          - db01:9100
    relabel_configs:
      - source_labels: [__address__]
        target_label: instance

  - job_name: php-fpm
    static_configs:
      - targets: ['web01:9253', 'web02:9253']

  - job_name: nginx
    static_configs:
      - targets: ['web01:9913', 'web02:9913']

  - job_name: redis
    static_configs:
      - targets: ['redis:9121']

  - job_name: postgres
    static_configs:
      - targets: ['db01:9187']

  - job_name: myapp
    metrics_path: /metrics
    bearer_token: ${METRICS_TOKEN}
    static_configs:
      - targets: ['web01:8080', 'web02:8080']

Alert Rules

# monitoring/alerts/servers.yml
groups:
  - name: server.alerts
    rules:
      - alert: HighCPU
        expr: 100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 85
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High CPU load on {{ $labels.instance }}"
          description: "CPU: {{ $value | printf \"%.1f\" }}%"

      - alert: LowMemory
        expr: (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes) * 100 < 10
        for: 2m
        labels:
          severity: critical
        annotations:
          summary: "Critically low memory on {{ $labels.instance }}"
          description: "Free: {{ $value | printf \"%.1f\" }}%"

      - alert: DiskSpaceLow
        expr: (node_filesystem_avail_bytes{fstype!~"tmpfs|fuse.lxcfs"} / node_filesystem_size_bytes) * 100 < 15
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Low disk space {{ $labels.instance }}:{{ $labels.mountpoint }}"

      - alert: HighPhpFpmQueue
        expr: phpfpm_listen_queue > 10
        for: 1m
        labels:
          severity: warning
        annotations:
          summary: "PHP-FPM queue full: {{ $value }} requests"

      - alert: PostgresDown
        expr: pg_up == 0
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "PostgreSQL unreachable on {{ $labels.instance }}"

      - alert: SlowQueries
        expr: rate(pg_stat_activity_max_tx_duration{state="active"}[5m]) > 30
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: "Slow PostgreSQL queries (>30 sec)"

Alertmanager: Notification Routing

# monitoring/alertmanager.yml
global:
  slack_api_url: ${SLACK_WEBHOOK_URL}

route:
  receiver: slack-notifications
  group_by: ['alertname', 'instance']
  group_wait: 30s
  group_interval: 5m
  repeat_interval: 4h

  routes:
    - match:
        severity: critical
      receiver: pagerduty-critical
      continue: true

    - match:
        severity: critical
      receiver: slack-critical

receivers:
  - name: slack-notifications
    slack_configs:
      - channel: '#monitoring'
        title: '{{ .GroupLabels.alertname }}'
        text: '{{ range .Alerts }}{{ .Annotations.summary }}{{ end }}'
        color: '{{ if eq .Status "firing" }}danger{{ else }}good{{ end }}'

  - name: slack-critical
    slack_configs:
      - channel: '#incidents'
        send_resolved: true

  - name: pagerduty-critical
    pagerduty_configs:
      - routing_key: ${PAGERDUTY_KEY}
        description: '{{ .GroupLabels.alertname }}: {{ .CommonAnnotations.summary }}'

Laravel: Custom Application Metrics

use Prometheus\CollectorRegistry;
use Prometheus\RenderTextFormat;

class MetricsController extends Controller
{
    public function __invoke(CollectorRegistry $registry): Response
    {
        // Laravel metrics
        $registry->getOrRegisterGauge('myapp', 'queue_size', 'Queue jobs count', ['queue'])
            ->set(Queue::size('emails'), ['emails']);

        $registry->getOrRegisterGauge('myapp', 'active_users', 'Active users in last 5 min')
            ->set(User::where('last_seen_at', '>', now()->subMinutes(5))->count());

        $registry->getOrRegisterGauge('myapp', 'failed_jobs', 'Failed jobs total')
            ->set(DB::table('failed_jobs')->count());

        $renderer = new RenderTextFormat();
        return response($renderer->render($registry->getMetricFamilySamples()), 200)
            ->header('Content-Type', RenderTextFormat::MIME_TYPE);
    }
}

Grafana: Importing Dashboards

Pre-built dashboards from Grafana.com:

• Node Exporter Full (ID: 1860) — server metrics
• PHP-FPM (ID: 4912) — queue, workers
• PostgreSQL (ID: 9628) — queries, indexes, transactions
• Redis (ID: 11835) — memory, commands, eviction

# Automatic import via provisioning
# monitoring/grafana/dashboards/dashboards.yml
apiVersion: 1
providers:
  - name: default
    folder: ''
    type: file
    options:
      path: /etc/grafana/provisioning/dashboards

Implementation Timeline