helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm install prometheus prometheus-community/kube-prometheus-stack \
  -n monitoring --create-namespace \
  --set grafana.adminPassword=secure-password \
  --set prometheus.prometheusSpec.retention=30d

# Pod CPU usage
sum(rate(container_cpu_usage_seconds_total{namespace="production"}[5m])) by (pod)

# Memory utilization
sum(container_memory_working_set_bytes{namespace="production"}) by (pod)
  / sum(container_spec_memory_limit_bytes{namespace="production"}) by (pod) * 100

# Request rate
sum(rate(http_requests_total[5m])) by (service)

# Error rate (5xx)
sum(rate(http_requests_total{status=~"5.."}[5m]))
  / sum(rate(http_requests_total[5m])) * 100

# P99 latency
histogram_quantile(0.99, sum(rate(http_request_duration_seconds_bucket[5m])) by (le))

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: api-server
  namespace: monitoring
spec:
  selector:
    matchLabels:
      app: api-server
  namespaceSelector:
    matchNames:
    - production
  endpoints:
  - port: metrics
    interval: 15s
    path: /metrics

apiVersion: v1
kind: ConfigMap
metadata:
  name: promtail-config
data:
  promtail.yaml: |
    server:
      http_listen_port: 3101
    positions:
      filename: /tmp/positions.yaml
    clients:
    - url: http://loki:3100/loki/api/v1/push
    scrape_configs:
    - job_name: kubernetes-pods
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - source_labels: [__meta_kubernetes_namespace]
        target_label: namespace
      - source_labels: [__meta_kubernetes_pod_name]
        target_label: pod

# Errors in production
{namespace="production"} |= "error"

# JSON log parsing
{app="api-server"} | json | status >= 500

# Rate of errors
rate({namespace="production"} |= "error" [5m])

apiVersion: opentelemetry.io/v1alpha1
kind: OpenTelemetryCollector
metadata:
  name: otel-collector
spec:
  mode: deployment
  config: |
    receivers:
      otlp:
        protocols:
          grpc:
            endpoint: 0.0.0.0:4317
          http:
            endpoint: 0.0.0.0:4318
    processors:
      batch:
        timeout: 10s
    exporters:
      jaeger:
        endpoint: jaeger-collector:14250
        tls:
          insecure: true
    service:
      pipelines:
        traces:
          receivers: [otlp]
          processors: [batch]
          exporters: [jaeger]

apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  name: api-server-slo
spec:
  groups:
  - name: slo.rules
    rules:
    # Availability SLO: 99.9%
    - record: slo:availability:ratio
      expr: |
        sum(rate(http_requests_total{status!~"5.."}[5m]))
        / sum(rate(http_requests_total[5m]))

    # Latency SLO: P99 < 200ms
    - record: slo:latency:p99
      expr: |
        histogram_quantile(0.99,
          sum(rate(http_request_duration_seconds_bucket[5m])) by (le))

  - name: slo.alerts
    rules:
    - alert: HighErrorRate
      expr: (1 - slo:availability:ratio) > 0.001
      for: 5m
      labels:
        severity: critical
      annotations:
        summary: "Error rate exceeds SLO (>0.1%)"

    - alert: HighLatency
      expr: slo:latency:p99 > 0.2
      for: 5m
      labels:
        severity: warning
      annotations:
        summary: "P99 latency exceeds 200ms"

apiVersion: v1
kind: Secret
metadata:
  name: alertmanager-config
stringData:
  alertmanager.yaml: |
    global:
      resolve_timeout: 5m
    route:
      receiver: 'default'
      group_by: ['alertname', 'namespace']
      group_wait: 30s
      group_interval: 5m
      repeat_interval: 12h
      routes:
      - match:
          severity: critical
        receiver: 'pagerduty'
      - match:
          severity: warning
        receiver: 'slack'
    receivers:
    - name: 'default'
      slack_configs:
      - channel: '#alerts'
        api_url: '${SLACK_WEBHOOK}'
    - name: 'pagerduty'
      pagerduty_configs:
      - service_key: '${PD_SERVICE_KEY}'
    - name: 'slack'
      slack_configs:
      - channel: '#alerts'

Monitoring Problem?
│
├── No metrics
│   ├── Check ServiceMonitor selector
│   ├── Verify /metrics endpoint
│   └── Check Prometheus targets
│
├── Missing logs
│   ├── Check Promtail/Fluentbit pods
│   ├── Verify log format
│   └── Check Loki ingestion
│
└── Alert not firing
    ├── Check PromQL expression
    ├── Verify thresholds
    └── Check Alertmanager routes

# Prometheus targets
kubectl port-forward -n monitoring svc/prometheus 9090
# Visit /targets

# Grafana access
kubectl port-forward -n monitoring svc/grafana 3000

# Check ServiceMonitors
kubectl get servicemonitors -A

# Alertmanager status
kubectl port-forward -n monitoring svc/alertmanager 9093