// nodeLookup is used to handle a node query func (d *DNSServer) nodeLookup(network, datacenter, node string, req, resp *dns.Msg) { // Only handle ANY and A type requests qType := req.Question[0].Qtype if qType != dns.TypeANY && qType != dns.TypeA { return } // Make an RPC request args := structs.NodeSpecificRequest{ Datacenter: datacenter, Node: node, QueryOptions: structs.QueryOptions{AllowStale: d.config.AllowStale}, } var out structs.IndexedNodeServices RPC: if err := d.agent.RPC("Catalog.NodeServices", &args, &out); err != nil { d.logger.Printf("[ERR] dns: rpc error: %v", err) resp.SetRcode(req, dns.RcodeServerFailure) return } // Verify that request is not too stale, redo the request if args.AllowStale && out.LastContact > d.config.MaxStale { args.AllowStale = false d.logger.Printf("[WARN] dns: Query results too stale, re-requesting") goto RPC } // If we have no address, return not found! if out.NodeServices == nil { resp.SetRcode(req, dns.RcodeNameError) return } // Add the node record records := d.formatNodeRecord(&out.NodeServices.Node, out.NodeServices.Node.Address, req.Question[0].Name, qType, d.config.NodeTTL) if records != nil { resp.Answer = append(resp.Answer, records...) } }