Prometheus Integration¶

NthLayer uses Prometheus for metric discovery, SLO queries, and alert rules.

Configuration¶

Via Setup Wizard¶

nthlayer setup

Via Environment Variables¶

export NTHLAYER_PROMETHEUS_URL=http://prometheus:9090

# If authentication required
export NTHLAYER_METRICS_USER=admin
export NTHLAYER_METRICS_PASSWORD=secret

Via Config File¶

# ~/.nthlayer/config.yaml
prometheus:
  default: default
  profiles:
    default:
      url: http://localhost:9090
      type: prometheus
    production:
      url: https://prometheus-prod.example.com
      type: prometheus
      username: admin
      password_secret: prometheus/password

Supported Backends¶

Type	Description
`prometheus`	Standard Prometheus server
`mimir`	Grafana Mimir
`grafana-cloud`	Grafana Cloud Prometheus

What NthLayer Generates¶

Alert Rules¶

groups:
  - name: payment-api-alerts
    rules:
      - alert: PaymentApiHighErrorRate
        expr: |
          sum(rate(http_requests_total{service="payment-api",status=~"5.."}[5m])) /
          sum(rate(http_requests_total{service="payment-api"}[5m])) > 0.01
        for: 5m
        labels:
          severity: critical
          service: payment-api
        annotations:
          summary: High error rate on payment-api
          description: Error rate is {{ $value | humanizePercentage }}

Recording Rules¶

groups:
  - name: payment-api-recording
    rules:
      - record: service:http_requests:rate5m
        expr: sum(rate(http_requests_total{service="payment-api"}[5m]))
      - record: service:http_errors:rate5m
        expr: sum(rate(http_requests_total{service="payment-api",status=~"5.."}[5m]))
      - record: service:http_latency_p99:5m
        expr: |
          histogram_quantile(0.99,
            sum by (le) (rate(http_request_duration_seconds_bucket{service="payment-api"}[5m]))
          )

SLO Queries¶

NthLayer queries Prometheus for live SLO status:

nthlayer slo collect payment-api.yaml

Uses queries like:

# Availability over 30 days
avg_over_time(
  (
    sum(rate(http_requests_total{service="payment-api",status!~"5.."}[5m])) /
    sum(rate(http_requests_total{service="payment-api"}[5m]))
  )[30d:5m]
)

Metric Discovery¶

NthLayer discovers available metrics to customize dashboards:

# Discovers metrics matching service label
nthlayer plan payment-api.yaml --discover

Testing Connection¶

nthlayer setup --test

  Prometheus (http://localhost:9090)
    [OK] Connected (Prometheus 2.45.0)

Troubleshooting¶

Connection Refused¶

[FAIL] Connection refused - is Prometheus running?

Verify Prometheus is running: curl http://localhost:9090/-/healthy
Check firewall rules
Verify URL is correct

Authentication Failed¶

[FAIL] Authentication required

Set NTHLAYER_METRICS_USER and NTHLAYER_METRICS_PASSWORD
Or configure in ~/.nthlayer/config.yaml

No Metrics Found¶

Ensure your application exports metrics with service label
Check metric names match expected patterns