pancheri/blackhole.go

package pancheri

import (
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promauto"
	"slices"
)

var (
	blockedDomains = promauto.NewGauge(prometheus.GaugeOpts{
		Name: "pancheri_blackhole_blocked_domains_total",
		Help: "Number of blocked domains on the blackhole blocklist",
	})
	blockHits = promauto.NewCounter(prometheus.CounterOpts{
		Name: "pancheri_blackhole_block_hits_total",
		Help: "Number of requests that have hit the blocklist",
	})
	blockMisses = promauto.NewCounter(prometheus.CounterOpts{
		Name: "pancheri_blackhole_misses_total",
		Help: "Number of requests that have missed the blocklist",
	})
)

type BlackholeFile struct {
	DenyDomains []string `yaml:"deny_domains"`
}

type Blackholer struct {
	DenyDomains []string
}

func (b *Blackholer) ShouldBlock(domain string) bool {
	blockedDomains.Set(float64(len(b.DenyDomains)))
	blocked := slices.Contains(b.DenyDomains, domain)
	if blocked {
		blockHits.Inc()
	} else {
		blockMisses.Inc()
	}

	return blocked
}