add AXFR request handling to support slaves

pkg/database/db.go

@@ -263,6 +263,50 @@ func (d *acmednsdb) GetByUsername(u uuid.UUID) (acmedns.ACMETxt, error) {
 	return acmedns.ACMETxt{}, fmt.Errorf("user not found: %s", u.String())
 }
 
+func (d *acmednsdb) GetTXTForAllDomains() ([]acmedns.TXTRecord, error) {
+	d.Mutex.Lock()
+	defer d.Mutex.Unlock()
+
+	var txts []acmedns.TXTRecord
+
+	getSQL := `
+        SELECT Subdomain, Value FROM txt
+    `
+	if d.Config.Database.Engine == "sqlite" {
+		getSQL = getSQLiteStmt(getSQL)
+	}
+
+	sm, err := d.DB.Prepare(getSQL)
+	if err != nil {
+		return txts, err
+	}
+	defer sm.Close()
+
+	rows, err := sm.Query()
+	if err != nil {
+		return txts, err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var subdomain string
+		var value string
+
+		err = rows.Scan(&subdomain, &value)
+		if err != nil {
+			return txts, err
+		}
+
+		d.Logger.Debugw("GetTXTForAllDomains() TXT Record:", subdomain, value)
+		txts = append(txts, acmedns.TXTRecord{
+			Subdomain: subdomain,
+			Value:     value,
+		})
+	}
+
+	return txts, nil
+}
+
 func (d *acmednsdb) GetTXTForDomain(domain string) ([]string, error) {
 	d.Mutex.Lock()
 	defer d.Mutex.Unlock()