Implement libdns ZoneLister interface for provider

_example/main.go

@@ -25,6 +25,15 @@ func main() {
 
 	provider := vultr.Provider{APIToken: token}
 
+	zones, err := provider.ListZones(context.TODO())
+	if err != nil {
+		fmt.Printf("ERROR: %s\n", err.Error())
+	}
+
+	for _, zone := range zones {
+		fmt.Printf("%s\n", zone.Name)
+	}
+
 	records, err := provider.GetRecords(context.TODO(), zone)
 	if err != nil {
 		fmt.Printf("ERROR: %s\n", err.Error())

client.go

@@ -121,3 +121,35 @@ func (p *Provider) updateDNSRecord(ctx context.Context, domain string, record li
 
 	return record, nil
 }
+
+func (p *Provider) getDNSZones(ctx context.Context) ([]libdns.Zone, error) {
+	p.client.mutex.Lock()
+	defer p.client.mutex.Unlock()
+
+	p.getClient()
+
+	listOptions := &govultr.ListOptions{}
+
+	var zones []libdns.Zone
+	for {
+		dns_zones, meta, _, err := p.client.vultr.Domain.List(ctx, listOptions)
+		if err != nil {
+			return zones, err
+		}
+
+		for _, entry := range dns_zones {
+			zone := libdns.Zone{
+				Name: entry.Domain,
+			}
+			zones = append(zones, zone)
+		}
+
+		if meta.Links.Next == "" {
+			break
+		}
+
+		listOptions.Cursor = meta.Links.Next
+	}
+
+	return zones, nil
+}

provider.go

@@ -83,10 +83,21 @@ func (p *Provider) SetRecords(ctx context.Context, zone string, records []libdns
 	return setRecords, nil
 }
 
+func (p *Provider) ListZones(ctx context.Context) ([]libdns.Zone, error) {
+	zones, err := p.getDNSZones(ctx)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return zones, nil
+}
+
 // Interface guards
 var (
 	_ libdns.RecordGetter   = (*Provider)(nil)
 	_ libdns.RecordAppender = (*Provider)(nil)
 	_ libdns.RecordSetter   = (*Provider)(nil)
 	_ libdns.RecordDeleter  = (*Provider)(nil)
+	_ libdns.ZoneLister     = (*Provider)(nil)
 )