initial commit

netboxdns.go

@@ -0,0 +1,109 @@
+package netboxdns
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/coredns/coredns/plugin"
+	"github.com/coredns/coredns/plugin/pkg/fall"
+	"github.com/coredns/coredns/plugin/pkg/log"
+	"github.com/coredns/coredns/request"
+	"github.com/doubleu-labs/coredns-netbox-plugin-dns/internal/netbox"
+	"github.com/miekg/dns"
+)
+
+const (
+	defaultHTTPClientTimeout time.Duration = time.Second * 5
+	pluginName               string        = "netboxdns"
+)
+
+var logger log.P
+
+func init() {
+	logger = log.NewWithPlugin(pluginName)
+}
+
+type NetboxDNS struct {
+	Next plugin.Handler
+
+	requestClient *netbox.APIRequestClient
+
+	zones []string
+	fall  fall.F
+}
+
+func NewNetboxDNS() *NetboxDNS {
+	return &NetboxDNS{
+		requestClient: &netbox.APIRequestClient{
+			Client: &http.Client{
+				Timeout: defaultHTTPClientTimeout,
+			},
+		},
+		zones: []string{"."},
+	}
+}
+
+// Name implements the plugin.Handler interface
+func (NetboxDNS) Name() string {
+	return pluginName
+}
+
+// ServeDNS implements the plugin.Handler interface
+func (netboxdns *NetboxDNS) ServeDNS(
+	reqContext context.Context,
+	respWriter dns.ResponseWriter,
+	reqMsg *dns.Msg,
+) (int, error) {
+	state := request.Request{W: respWriter, Req: reqMsg}
+	qname := state.QName()
+	qtype := state.QType()
+
+	// check if plugin is configured to respond to the requested zone
+	respondingZone := plugin.Zones(netboxdns.zones).Matches(qname)
+	if respondingZone == "" {
+		return netboxdns.nextOrFailure(reqContext, respWriter, reqMsg)
+	}
+
+	response, err := netboxdns.lookup(qname, qtype, state.Family())
+	if err != nil {
+		return dns.RcodeServerFailure, err
+	}
+	if response.LookupResult == lookupNameError &&
+		netboxdns.fall.Through(qname) {
+		return netboxdns.nextOrFailure(reqContext, respWriter, reqMsg)
+	}
+
+	respMsg := &dns.Msg{
+		Answer: response.Answer,
+		Ns:     response.Ns,
+		Extra:  response.Extra,
+	}
+	respMsg.SetReply(reqMsg)
+	respMsg.Authoritative = true
+
+	switch response.LookupResult {
+	case lookupSuccess:
+	case lookupNameError:
+		respMsg.Rcode = dns.RcodeNameError
+	case lookupDelegation:
+		respMsg.Authoritative = false
+	}
+
+	respWriter.WriteMsg(respMsg)
+	return dns.RcodeSuccess, nil
+}
+
+func (netboxdns *NetboxDNS) nextOrFailure(
+	ctx context.Context,
+	writer dns.ResponseWriter,
+	request *dns.Msg,
+) (int, error) {
+	return plugin.NextOrFailure(
+		pluginName,
+		netboxdns.Next,
+		ctx,
+		writer,
+		request,
+	)
+}