Ban NO_PURGE when using BIND and others. (#180)

pkg/normalize/validate.go

@@ -249,6 +249,11 @@ func NormalizeAndValidateConfig(config *models.DNSConfig) (errs []error) {
 			} else {
 				pTypes = append(pTypes, pType)
 			}
+
+			//If NO_PURGE is in use, make sure this *isn't* a provider that *doesn't* support NO_PURGE.
+			if domain.KeepUnknown && providers.ProviderHasCabability(pType, providers.CantUseNOPURGE) {
+				errs = append(errs, fmt.Errorf("%s uses NO_PURGE which is not supported by %s(%s)", domain.Name, p, pType))
+			}
 		}
 
 		// Normalize Nameservers.

providers/bind/bindProvider.go

@@ -47,7 +47,7 @@ func initBind(config map[string]string, providermeta json.RawMessage) (providers
 }
 
 func init() {
-	providers.RegisterDomainServiceProviderType("BIND", initBind, providers.CanUsePTR, providers.CanUseSRV, providers.CanUseCAA)
+	providers.RegisterDomainServiceProviderType("BIND", initBind, providers.CanUsePTR, providers.CanUseSRV, providers.CanUseCAA, providers.CantUseNOPURGE)
 }
 
 type SoaInfo struct {

providers/namecheap/namecheap.go

@@ -18,6 +18,8 @@ type Namecheap struct {
 
 func init() {
 	providers.RegisterRegistrarType("NAMECHEAP", newReg)
+	// NOTE(tlim): If in the future the DNS Service Provider is implemented,
+	// most likely it will require providers.CantUseNOPURGE.
 }
 
 func newReg(m map[string]string) (providers.Registrar, error) {

providers/providers.go

@@ -49,6 +49,11 @@ const (
 	CanUseSRV
 	// CanUseCAA indicates the provider can handle CAA records
 	CanUseCAA
+	// CantUseNOPURGE indicates NO_PURGE is broken for this provider. To make it
+	// work would require complex emulation of an incremental update mechanism,
+	// so it is easier to simply mark this feature as not working for this
+	// provider.
+	CantUseNOPURGE
 )
 
 func ProviderHasCabability(pType string, cap Capability) bool {