NEW PROVIDER: MSDNS (#1005)

* New provider
* Add support for SRV records
* Modify ACTIVEDIRECTORY_PS provider to warn that it is deprecated.

providers/msdns/msdnsProvider.go

@@ -0,0 +1,129 @@
+package msdns
+
+import (
+	"encoding/json"
+	"fmt"
+	"runtime"
+
+	"github.com/StackExchange/dnscontrol/v3/models"
+	"github.com/StackExchange/dnscontrol/v3/providers"
+)
+
+// This is the struct that matches either (or both) of the Registrar and/or DNSProvider interfaces:
+type msdnsProvider struct {
+	dnsserver string      // Which DNS Server to update
+	pssession string      // Remote machine to PSSession to
+	shell     DNSAccessor // Handle for
+}
+
+var features = providers.DocumentationNotes{
+	providers.CanGetZones:            providers.Can(),
+	providers.CanUseAlias:            providers.Cannot(),
+	providers.CanUseCAA:              providers.Cannot(),
+	providers.CanUseDS:               providers.Unimplemented(),
+	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(),
+}
+
+// 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)
+}
+
+func newDNS(config map[string]string, metadata json.RawMessage) (providers.DNSServiceProvider, error) {
+
+	if runtime.GOOS != "windows" {
+		fmt.Println("INFO: PowerShell not available. Disabling Active Directory provider.")
+		return providers.None{}, nil
+	}
+
+	var err error
+
+	p := &msdnsProvider{
+		dnsserver: config["dnsserver"],
+	}
+	p.shell, err = newPowerShell(config)
+	if err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+// Section 3: Domain Service Provider (DSP) related functions
+
+// NB(tal): To future-proof your code, all new providers should
+// implement GetDomainCorrections exactly as you see here
+// (byte-for-byte the same). In 3.0
+// we plan on using just the individual calls to GetZoneRecords,
+// PostProcessRecords, and so on.
+//
+// Currently every provider does things differently, which prevents
+// us from doing things like using GetZoneRecords() of a provider
+// to make convertzone work with all providers.
+
+// GetDomainCorrections get the current and existing records,
+// post-process them, and generate corrections.
+func (client *msdnsProvider) GetDomainCorrections(dc *models.DomainConfig) ([]*models.Correction, error) {
+	existing, err := client.GetZoneRecords(dc.Name)
+	if err != nil {
+		return nil, err
+	}
+	models.PostProcessRecords(existing)
+	clean := PrepFoundRecords(existing)
+	PrepDesiredRecords(dc)
+	return client.GenerateDomainCorrections(dc, clean)
+}
+
+// GetZoneRecords gathers the DNS records and converts them to
+// dnscontrol's format.
+func (client *msdnsProvider) GetZoneRecords(domain string) (models.Records, error) {
+
+	// Get the existing DNS records in native format.
+	nativeExistingRecords, err := client.shell.GetDNSZoneRecords(client.dnsserver, domain)
+	if err != nil {
+		return nil, err
+	}
+	// Convert them to DNScontrol's native format:
+	existingRecords := make([]*models.RecordConfig, 0, len(nativeExistingRecords))
+	for _, rr := range nativeExistingRecords {
+		rc, err := nativeToRecords(rr, domain)
+		if err != nil {
+			return nil, err
+		}
+		if rc != nil {
+			existingRecords = append(existingRecords, rc)
+		}
+	}
+
+	return existingRecords, nil
+}
+
+// PrepFoundRecords munges any records to make them compatible with
+// this provider. Usually this is a no-op.
+func PrepFoundRecords(recs models.Records) models.Records {
+	// If there are records that need to be modified, removed, etc. we
+	// do it here.  Usually this is a no-op.
+	return recs
+}
+
+// PrepDesiredRecords munges any records to best suit this provider.
+func PrepDesiredRecords(dc *models.DomainConfig) {
+	// Sort through the dc.Records, eliminate any that can't be
+	// supported; modify any that need adjustments to work with the
+	// provider.  We try to do minimal changes otherwise it gets
+	// confusing.
+
+	dc.Punycode()
+}
+
+// NB(tlim): If we want to implement a registrar, refer to
+// http://go.microsoft.com/fwlink/?LinkId=288158
+// (Get-DnsServerZoneDelegation) for hints about which PowerShell
+// commands to use.