Re-engineer TXT records for simplicity and better compliance (#1063)

TXT records are now handled different.

1. The raw input from dnsconfig.js is passed all the way to the provider. The provider can determine if it can or can't handle such records (auditrecords.go) and processes them internally as such.
2. The CanUseTXTMulti capability is no longer needed.

* DSPs now register a table of functions
* Use audits for txt record variations
* unit tests pass. integration fails.
* fix deepcopy problem
* rename to AuditRecordSupport
* Reduce use of TXTMulti
* Remove CanUseTXTMulti
* fix Test Skip
* fix DO
* fix vultr
* fix NDC
* msdns fixes
* Fix powerdns and cloudflare
* HEDNS: Fix usage of target field to resolve TXT handling (#1067)
* Fix HEXONET

Co-authored-by: Robert Blenkinsopp <robert@blenkinsopp.net>
Co-authored-by: Jakob Ackermann <das7pad@outlook.com>

providers/msdns/auditrecords.go

@@ -0,0 +1,43 @@
+package msdns
+
+import (
+	"github.com/StackExchange/dnscontrol/v3/models"
+	"github.com/StackExchange/dnscontrol/v3/pkg/recordaudit"
+)
+
+// AuditRecords returns an error if any records are not
+// supportable by this provider.
+func AuditRecords(records []*models.RecordConfig) error {
+
+	if err := recordaudit.TxtNoMultipleStrings(records); err != nil {
+		return err
+	}
+	// Still needed as of 2021-03-01
+
+	if err := recordaudit.TxtNotEmpty(records); err != nil {
+		return err
+	}
+	// Still needed as of 2021-03-01
+
+	if err := recordaudit.TxtNoBackticks(records); err != nil {
+		return err
+	}
+	// Still needed as of 2021-03-01
+
+	if err := recordaudit.TxtNoDoubleQuotes(records); err != nil {
+		return err
+	}
+	// Still needed as of 2021-03-01
+
+	if err := recordaudit.TxtNoSingleQuotes(records); err != nil {
+		return err
+	}
+	// Still needed as of 2021-03-01
+
+	if err := recordaudit.TxtNoLen255(records); err != nil {
+		return err
+	}
+	// Still needed as of 2021-03-01
+
+	return nil
+}

providers/msdns/corrections.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/StackExchange/dnscontrol/v3/models"
 	"github.com/StackExchange/dnscontrol/v3/pkg/diff"
+	"github.com/StackExchange/dnscontrol/v3/pkg/txtutil"
 )
 
 // GetDomainCorrections gets existing records, diffs them against existing, and returns corrections.
@@ -18,6 +19,7 @@ func (c *msdnsProvider) GenerateDomainCorrections(dc *models.DomainConfig, exist
 
 	// Normalize
 	models.PostProcessRecords(foundRecords)
+	txtutil.SplitSingleLongTxt(dc.Records) // Autosplit long TXT records
 
 	differ := diff.New(dc)
 	_, creates, dels, modifications, err := differ.IncrementalDiff(foundRecords)

providers/msdns/msdnsProvider.go

@@ -6,6 +6,7 @@ import (
 	"runtime"
 
 	"github.com/StackExchange/dnscontrol/v3/models"
+	"github.com/StackExchange/dnscontrol/v3/pkg/txtutil"
 	"github.com/StackExchange/dnscontrol/v3/providers"
 )
 
@@ -24,7 +25,6 @@ var features = providers.DocumentationNotes{
 	providers.CanUsePTR:              providers.Can(),
 	providers.CanUseSRV:              providers.Can(),
 	providers.CanUseTLSA:             providers.Unimplemented(),
-	providers.CanUseTXTMulti:         providers.Unimplemented(),
 	providers.DocCreateDomains:       providers.Cannot("This provider assumes the zone already existing on the dns server"),
 	providers.DocDualHost:            providers.Cannot("This driver does not manage NS records, so should not be used for dual-host scenarios"),
 	providers.DocOfficiallySupported: providers.Can(),
@@ -33,7 +33,11 @@ var features = providers.DocumentationNotes{
 // Register with the dnscontrol system.
 //   This establishes the name (all caps), and the function to call to initialize it.
 func init() {
-	providers.RegisterDomainServiceProviderType("MSDNS", newDNS, features)
+	fns := providers.DspFuncs{
+		Initializer:    newDNS,
+		AuditRecordsor: AuditRecords,
+	}
+	providers.RegisterDomainServiceProviderType("MSDNS", fns, features)
 }
 
 func newDNS(config map[string]string, metadata json.RawMessage) (providers.DNSServiceProvider, error) {
@@ -76,6 +80,8 @@ func (client *msdnsProvider) GetDomainCorrections(dc *models.DomainConfig) ([]*m
 		return nil, err
 	}
 	models.PostProcessRecords(existing)
+	txtutil.SplitSingleLongTxt(dc.Records) // Autosplit long TXT records
+
 	clean := PrepFoundRecords(existing)
 	PrepDesiredRecords(dc)
 	return client.GenerateDomainCorrections(dc, clean)

providers/msdns/powershell.go

@@ -162,6 +162,8 @@ func generatePSDelete(dnsserver, domain string, rec *models.RecordConfig) string
 	fmt.Fprintf(&b, ` -RRType "%s"`, rec.Type)
 	if rec.Type == "MX" {
 		fmt.Fprintf(&b, ` -RecordData %d,"%s"`, rec.MxPreference, rec.GetTargetField())
+	} else if rec.Type == "TXT" {
+		fmt.Fprintf(&b, ` -RecordData %s`, rec.GetTargetField())
 	} else if rec.Type == "SRV" {
 		// https://www.gitmemory.com/issue/MicrosoftDocs/windows-powershell-docs/1149/511916884
 		fmt.Fprintf(&b, ` -RecordData %d,%d,%d,"%s"`, rec.SrvPriority, rec.SrvWeight, rec.SrvPort, rec.GetTargetField())
@@ -214,7 +216,9 @@ func generatePSCreate(dnsserver, domain string, rec *models.RecordConfig) string
 	//case "WKS":
 	//	fmt.Fprintf(&b, ` -Wks -InternetAddress <IPAddress> -InternetProtocol {UDP | TCP} -Service <String[]>`, rec.GetTargetField())
 	case "TXT":
-		fmt.Fprintf(&b, ` -Txt -DescriptiveText "%s"`, rec.GetTargetField())
+		fmt.Printf("DEBUG TXT len = %v\n", rec.TxtStrings)
+		fmt.Printf("DEBUG TXT target = %q\n", rec.GetTargetField())
+		fmt.Fprintf(&b, ` -Txt -DescriptiveText %s`, rec.GetTargetField())
 	//case "RT":
 	//	fmt.Fprintf(&b, ` -RT -IntermediateHost <String> -Preference <UInt16>`, rec.GetTargetField())
 	//case "RP":