retrieve list of records instead of a single record

handler/handler.go

@@ -62,9 +62,12 @@ func (h *Handler) buildMessage(m *dns.Msg) (*dns.Msg, error) {
 		return nil, errors.New("unsupported dns type")
 	}
 
-	record, err := h.storage.Get(domain)
-
-	if errors.Is(err, storage.ErrRecordNotFound) {
+	records, err := h.storage.GetByDomain(domain)
+	if err != nil {
+		logEntry.WithField("reason", err).Error("unable to get record from database")
+		return nil, err
+	}
+	if len(records) == 0 {
 		logEntry.Info("unregistered domain")
 
 		forwardedMessage, err := h.forwardQuery(m)
@@ -76,25 +79,23 @@ func (h *Handler) buildMessage(m *dns.Msg) (*dns.Msg, error) {
 		return forwardedMessage, err
 	}
 
-	if err != nil {
-		logEntry.WithField("reason", err).Error("unable to get record from database")
-		return nil, err
-	}
-
 	logEntry.Info("domain found")
 
 	var message dns.Msg
 	message.SetReply(m)
 	message.Authoritative = true
-	message.Answer = append(message.Answer, &dns.A{
-		Hdr: dns.RR_Header{
-			Name:   domain,
-			Rrtype: dns.TypeA,
-			Class:  dns.ClassINET,
-			Ttl:    60,
-		},
-		A: net.ParseIP(record.IPv4),
-	})
+
+	for _, record := range records {
+		message.Answer = append(message.Answer, &dns.A{
+			Hdr: dns.RR_Header{
+				Name:   domain,
+				Rrtype: dns.TypeA,
+				Class:  dns.ClassINET,
+				Ttl:    60,
+			},
+			A: net.ParseIP(record.IPv4),
+		})
+	}
 
 	return &message, nil
 }

storage/sqlite/sqlite.go

@@ -32,7 +32,7 @@ func New(dsn string) (*SQLite, error) {
 func (sq *SQLite) Put(r storage.Record) (string, error) {
 	query := `insert into records(
     	domain, ipv4, ipv6, ttl, type
-	) values(?, ?, ?, ?, ?) returning id`
+	) values(?, nullif(?, ''), nullif(?, ''), ?, ?) returning id`
 
 	var id string
 	err := sq.db.QueryRow(query, r.Domain, r.IPv4, r.IPv6, r.TTL, r.Type).Scan(&id)
@@ -45,7 +45,7 @@ func (sq *SQLite) Put(r storage.Record) (string, error) {
 
 func (sq *SQLite) Get(identifier string) (*storage.Record, error) {
 	var record storage.Record
-	query := `select id, domain, ipv4, ipv6, ttl, type from records where id = ?`
+	query := `select id, domain, ifnull(ipv4, '') as ipv4, ifnull(ipv6, '') as ipv6, ttl, type from records where id = ?`
 	err := sq.db.QueryRow(query, identifier).
 		Scan(&record.ID, &record.Domain, &record.IPv4, &record.IPv6, &record.TTL, &record.Type)
 
@@ -60,6 +60,16 @@ func (sq *SQLite) Get(identifier string) (*storage.Record, error) {
 	return &record, nil
 }
 
+func (sq *SQLite) GetByDomain(domain string) ([]*storage.Record, error) {
+	var records []*storage.Record
+
+	query := `select id, domain, ifnull(ipv4, '') as ipv4, ifnull(ipv6, '') as ipv6, ttl, type from records where domain = ?`
+	if err := sq.db.Select(&records, query, domain); err != nil {
+		return nil, err
+	}
+	return records, nil
+}
+
 func (sq *SQLite) Delete(identifier string) error {
 	query := `delete from records where id = ?`
 	_, err := sq.db.Exec(query, identifier)
@@ -69,7 +79,7 @@ func (sq *SQLite) Delete(identifier string) error {
 
 func (sq *SQLite) List() ([]*storage.Record, error) {
 	var records []*storage.Record
-	query := `select id, domain, ipv4, ipv6, ttl, type from records`
+	query := `select id, domain, ifnull(ipv4, '') as ipv4, ifnull(ipv6, '') as ipv6, ttl, type from records`
 	if err := sq.db.Select(&records, query); err != nil {
 		return nil, err
 	}

storage/storage.go

@@ -21,6 +21,7 @@ type Record struct {
 type Storage interface {
 	Put(r Record) (string, error)
 	Get(identifier string) (*Record, error)
+	GetByDomain(domain string) ([]*Record, error)
 	Delete(identifier string) error
 	List() ([]*Record, error)
 	Close() error