package main
<p>import (
"net/http"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)</p><p>var (
httpRequestsTotal = prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "http_requests_total",
Help: "Total number of HTTP requests.",
},
[]string{"method", "endpoint", "status"},
)
)</p><p>func init() {
prometheus.MustRegister(httpRequestsTotal)
}</p><p>func handler(w http.ResponseWriter, r *http.Request) {
httpRequestsTotal.WithLabelValues(r.Method, r.URL.Path, "200").Inc()
w.Write([]byte("Hello World"))
}</p><p>func main() {
http.Handle("/metrics", promhttp.Handler())
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}</p>

scrape_configs:
  - job_name: 'go-service'
    static_configs:
      - targets: ['your-go-service-ip:8080']

groups:
- name: go_service_alerts
  rules:
  - alert: HighRequestLatency
    expr: histogram_quantile(0.95, sum(rate(http_request_duration_seconds_bucket[5m])) by (le)) > 0.5
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: "High latency on {{ $labels.instance }}"
      description: "95th percentile latency is above 500ms"
<ul><li>alert: HighErrorRate
expr: sum(rate(http_requests_total{status=~"5.."}[5m])) / sum(rate(http_requests_total[5m])) > 0.05
for: 3m
labels:
severity: critical
annotations:
summary: "High error rate on {{ $labels.instance }}"
description: "Error rate is above 5%"

rule_files:
</li><li>"alerts.yml"

route:
  receiver: email-notifications
  group_wait: 30s
  group_interval: 5m
  repeat_interval: 1h
<p>receivers:</p><ul><li>name: email-notifications
email_configs:<ul><li>to: admin@example.com
from: alertmanager@example.com
smarthost: smtp.example.com:587
auth_username: "alertmanager"
auth_identity: "alertmanager@example.com"
auth_password: "password"

alerting:
alertmanagers:
- static_configs:
    - targets: ["localhost:9093"]