initial commit

yamlplugin.go

@@ -0,0 +1,99 @@
+package yamlzone
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+
+	"github.com/coredns/caddy"
+	"github.com/coredns/coredns/core/dnsserver"
+	"github.com/coredns/coredns/plugin"
+	clog "github.com/coredns/coredns/plugin/pkg/log"
+	"github.com/coredns/coredns/request"
+
+	"github.com/miekg/dns"
+)
+
+type YamlPlugin struct {
+	Next   plugin.Handler
+	Zone   *Zone
+	Config YamlPluginConfig
+}
+
+type YamlPluginConfig struct {
+	DefaultTtl uint64
+}
+
+var log = clog.NewWithPlugin("yaml")
+
+func (y YamlPlugin) lookupRRs(qname string, qtype string) ([]dns.RR, bool) {
+	records, ok := y.Zone.LookupType(qname, qtype)
+	if !ok {
+		return nil, false
+	}
+	rrs := []dns.RR{}
+	for _, record := range records {
+		ttl := record.Ttl
+		if ttl == 0 {
+			ttl = y.Config.DefaultTtl
+		}
+		rr, err := dns.NewRR(fmt.Sprintf("%s %d %s %s", qname, ttl, record.Type, record.Value))
+		if err != nil {
+			return nil, false
+		}
+		rrs = append(rrs, rr)
+	}
+	return rrs, true
+}
+
+func (y YamlPlugin) Name() string { return "yaml" }
+
+func (y YamlPlugin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+	state := request.Request{W: w, Req: r}
+	qname := state.Name()
+	qtype := state.Type()
+
+	reply := new(dns.Msg)
+	reply.SetReply(r)
+	reply.Authoritative = true
+
+	rrs, ok := y.lookupRRs(qname, qtype)
+	if !ok {
+		return dns.RcodeNameError, nil
+	}
+	reply.Answer = rrs
+	w.WriteMsg(reply)
+	return dns.RcodeSuccess, nil
+}
+
+func setup(c *caddy.Controller) error {
+	c.Next() // yaml
+	filename := "zones.yaml"
+	if c.NextArg() {
+		filename = c.Val()
+	}
+	defaultTtl := uint64(60)
+	if c.NextArg() {
+		var err error
+		defaultTtl, err = strconv.ParseUint(c.Val(), 10, 32)
+		if err != nil {
+			return plugin.Error("yaml", fmt.Errorf("failed to parse default TTL: %w", err))
+		}
+	}
+	zone, err := LoadZone(filename)
+	if err != nil {
+		return plugin.Error("yaml", fmt.Errorf("failed to load zone from %s: %w", filename, err))
+	}
+	dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
+		return &YamlPlugin{
+			Next: next,
+			Zone: zone,
+			Config: YamlPluginConfig{
+				DefaultTtl: defaultTtl,
+			},
+		}
+	})
+	return nil
+}
+
+func init() { plugin.Register("yaml", setup) }