dnscontrol/providers/activedir/domains.go
Tom Limoncelli 2cbabd859b Make it easier to add new Rtypes. (#169)
* NEW: docs/adding-new-rtypes.md
* Mark all "if" and "switch" statements with `#rtype_variations`
* Make consistent use of `default: panic()`
2017-08-04 12:26:29 -07:00

310 lines
11 KiB
Go

package activedir
import (
"encoding/json"
"fmt"
"log"
"os"
"strings"
"time"
"github.com/TomOnTime/utfutil"
"github.com/miekg/dns/dnsutil"
"github.com/StackExchange/dnscontrol/models"
"github.com/StackExchange/dnscontrol/providers/diff"
)
const zoneDumpFilenamePrefix = "adzonedump"
type RecordConfigJson struct {
Name string `json:"hostname"`
Type string `json:"recordtype"`
Data string `json:"recorddata"`
TTL uint32 `json:"timetolive"`
}
func (c *adProvider) GetNameservers(string) ([]*models.Nameserver, error) {
//TODO: If using AD for publicly hosted zones, probably pull these from config.
return nil, nil
}
// GetDomainCorrections gets existing records, diffs them against existing, and returns corrections.
func (c *adProvider) GetDomainCorrections(dc *models.DomainConfig) ([]*models.Correction, error) {
dc.Filter(func(r *models.RecordConfig) bool {
if r.Type != "A" && r.Type != "CNAME" {
log.Printf("WARNING: Active Directory only manages A and CNAME records. Won't consider %s %s", r.Type, r.NameFQDN)
return false
}
return true
})
// Read foundRecords:
foundRecords, err := c.getExistingRecords(dc.Name)
if err != nil {
return nil, fmt.Errorf("c.getExistingRecords(%v) failed: %v", dc.Name, err)
}
differ := diff.New(dc)
_, creates, dels, modifications := differ.IncrementalDiff(foundRecords)
// NOTE(tlim): This provider does not delete records. If
// you need to delete a record, either delete it manually
// or see providers/activedir/doc.md for implementation tips.
// Generate changes.
corrections := []*models.Correction{}
for _, del := range dels {
corrections = append(corrections, c.deleteRec(dc.Name, del.Existing))
}
for _, cre := range creates {
corrections = append(corrections, c.createRec(dc.Name, cre.Desired)...)
}
for _, m := range modifications {
corrections = append(corrections, c.modifyRec(dc.Name, m))
}
return corrections, nil
}
// zoneDumpFilename returns the filename to use to write or read
// an activedirectory zone dump for a particular domain.
func zoneDumpFilename(domainname string) string {
return zoneDumpFilenamePrefix + "." + domainname + ".json"
}
// readZoneDump reads a pre-existing zone dump from adzonedump.*.json.
func (c *adProvider) readZoneDump(domainname string) ([]byte, error) {
// File not found is considered an error.
dat, err := utfutil.ReadFile(zoneDumpFilename(domainname), utfutil.WINDOWS)
if err != nil {
fmt.Println("Powershell to generate zone dump:")
fmt.Println(c.generatePowerShellZoneDump(domainname))
}
return dat, err
}
// powerShellLogCommand logs to flagPsLog that a PowerShell command is going to be run.
func logCommand(command string) error {
return logHelper(fmt.Sprintf("# %s\r\n%s\r\n", time.Now().UTC(), strings.TrimSpace(command)))
}
// powerShellLogOutput logs to flagPsLog that a PowerShell command is going to be run.
func logOutput(s string) error {
return logHelper(fmt.Sprintf("OUTPUT: START\r\n%s\r\nOUTPUT: END\r\n", s))
}
// powerShellLogErr logs that a PowerShell command had an error.
func logErr(e error) error {
err := logHelper(fmt.Sprintf("ERROR: %v\r\r", e)) //Log error to powershell.log
if err != nil {
return err //Bubble up error created in logHelper
}
return e //Bubble up original error
}
func logHelper(s string) error {
logfile, err := os.OpenFile(*flagPsLog, os.O_APPEND|os.O_RDWR|os.O_CREATE, 0660)
if err != nil {
return fmt.Errorf("error: Can not create/append to %#v: %v", *flagPsLog, err)
}
_, err = fmt.Fprintln(logfile, s)
if err != nil {
return fmt.Errorf("error: Append to %#v failed: %v", *flagPsLog, err)
}
if logfile.Close() != nil {
return fmt.Errorf("ERROR: Closing %#v failed: %v", *flagPsLog, err)
}
return nil
}
// powerShellRecord records that a PowerShell command should be executed later.
func powerShellRecord(command string) error {
recordfile, err := os.OpenFile(*flagPsFuture, os.O_APPEND|os.O_RDWR|os.O_CREATE, 0660)
if err != nil {
return fmt.Errorf("ERROR: Can not create/append to %#v: %v\n", *flagPsFuture, err)
}
_, err = recordfile.WriteString(command)
if err != nil {
return fmt.Errorf("ERROR: Append to %#v failed: %v\n", *flagPsFuture, err)
}
return recordfile.Close()
}
func (c *adProvider) getExistingRecords(domainname string) ([]*models.RecordConfig, error) {
//log.Printf("getExistingRecords(%s)\n", domainname)
// Get the JSON either from adzonedump or by running a PowerShell script.
data, err := c.getRecords(domainname)
if err != nil {
return nil, fmt.Errorf("getRecords failed on %#v: %v", domainname, err)
}
var recs []*RecordConfigJson
err = json.Unmarshal(data, &recs)
if err != nil {
return nil, fmt.Errorf("json.Unmarshal failed on %#v: %v", domainname, err)
}
result := make([]*models.RecordConfig, 0, len(recs))
for i := range recs {
t := recs[i].unpackRecord(domainname)
if t != nil {
result = append(result, t)
}
}
return result, nil
}
func (r *RecordConfigJson) unpackRecord(origin string) *models.RecordConfig {
rc := models.RecordConfig{}
rc.Name = strings.ToLower(r.Name)
rc.NameFQDN = dnsutil.AddOrigin(rc.Name, origin)
rc.Type = r.Type
rc.TTL = r.TTL
switch rc.Type { // #rtype_variations
case "A":
rc.Target = r.Data
case "CNAME":
rc.Target = strings.ToLower(r.Data)
case "NS", "SOA":
return nil
default:
log.Printf("Warning: Record of type %s found in AD zone. Will be ignored.", rc.Type)
return nil
}
return &rc
}
// powerShellDump runs a PowerShell command to get a dump of all records in a DNS zone.
func (c *adProvider) generatePowerShellZoneDump(domainname string) string {
cmdTxt := `@("REPLACE_WITH_ZONE") | %{
Get-DnsServerResourceRecord -ComputerName REPLACE_WITH_COMPUTER_NAME -ZoneName $_ | select hostname,recordtype,@{n="timestamp";e={$_.timestamp.tostring()}},@{n="timetolive";e={$_.timetolive.totalseconds}},@{n="recorddata";e={($_.recorddata.ipv4address,$_.recorddata.ipv6address,$_.recorddata.HostNameAlias,"other_record" -ne $null)[0]-as [string]}} | ConvertTo-Json > REPLACE_WITH_FILENAMEPREFIX.REPLACE_WITH_ZONE.json
}`
cmdTxt = strings.Replace(cmdTxt, "REPLACE_WITH_ZONE", domainname, -1)
cmdTxt = strings.Replace(cmdTxt, "REPLACE_WITH_COMPUTER_NAME", c.adServer, -1)
cmdTxt = strings.Replace(cmdTxt, "REPLACE_WITH_FILENAMEPREFIX", zoneDumpFilenamePrefix, -1)
return cmdTxt
}
// generatePowerShellCreate generates PowerShell commands to ADD a record.
func (c *adProvider) generatePowerShellCreate(domainname string, rec *models.RecordConfig) string {
content := rec.Target
text := "\r\n" // Skip a line.
text += fmt.Sprintf("Add-DnsServerResourceRecord%s", rec.Type)
text += fmt.Sprintf(` -ComputerName "%s"`, c.adServer)
text += fmt.Sprintf(` -ZoneName "%s"`, domainname)
text += fmt.Sprintf(` -Name "%s"`, rec.Name)
text += fmt.Sprintf(` -TimeToLive $(New-TimeSpan -Seconds %d)`, rec.TTL)
switch rec.Type { // #rtype_variations
case "CNAME":
text += fmt.Sprintf(` -HostNameAlias "%s"`, content)
case "A":
text += fmt.Sprintf(` -IPv4Address "%s"`, content)
case "NS":
text = fmt.Sprintf("\r\n"+`echo "Skipping NS update (%v %v)"`+"\r\n", rec.Name, rec.Target)
default:
panic(fmt.Errorf("ERROR: generatePowerShellCreate() does not yet handle recType=%s recName=%#v content=%#v)\n", rec.Type, rec.Name, content))
// We panic so that we quickly find any switch statements
// that have not been updated for a new RR type.
}
text += "\r\n"
return text
}
// generatePowerShellModify generates PowerShell commands to MODIFY a record.
func (c *adProvider) generatePowerShellModify(domainname, recName, recType, oldContent, newContent string, oldTTL, newTTL uint32) string {
var queryField, queryContent string
switch recType { // #rtype_variations
case "A":
queryField = "IPv4address"
queryContent = `"` + oldContent + `"`
case "CNAME":
queryField = "HostNameAlias"
queryContent = `"` + oldContent + `"`
default:
panic(fmt.Errorf("ERROR: generatePowerShellModify() does not yet handle recType=%s recName=%#v content=(%#v, %#v)\n", recType, recName, oldContent, newContent))
// We panic so that we quickly find any switch statements
// that have not been updated for a new RR type.
}
text := "\r\n" // Skip a line.
text += fmt.Sprintf(`echo "MODIFY %s %s %s old=%s new=%s"`, recName, domainname, recType, oldContent, newContent)
text += "\r\n"
text += "$OldObj = Get-DnsServerResourceRecord"
text += fmt.Sprintf(` -ComputerName "%s"`, c.adServer)
text += fmt.Sprintf(` -ZoneName "%s"`, domainname)
text += fmt.Sprintf(` -Name "%s"`, recName)
text += fmt.Sprintf(` -RRType "%s"`, recType)
text += fmt.Sprintf(" | Where-Object {$_.RecordData.%s -eq %s -and $_.HostName -eq \"%s\"}", queryField, queryContent, recName)
text += "\r\n"
text += `if($OldObj.Length -ne $null){ throw "Error, multiple results for Get-DnsServerResourceRecord" }`
text += "\r\n"
text += "$NewObj = $OldObj.Clone()"
text += "\r\n"
if oldContent != newContent {
text += fmt.Sprintf(`$NewObj.RecordData.%s = "%s"`, queryField, newContent)
text += "\r\n"
}
if oldTTL != newTTL {
text += fmt.Sprintf(`$NewObj.TimeToLive = New-TimeSpan -Seconds %d`, newTTL)
text += "\r\n"
}
text += "Set-DnsServerResourceRecord"
text += fmt.Sprintf(` -ComputerName "%s"`, c.adServer)
text += fmt.Sprintf(` -ZoneName "%s"`, domainname)
text += fmt.Sprintf(` -NewInputObject $NewObj -OldInputObject $OldObj`)
text += "\r\n"
return text
}
func (c *adProvider) generatePowerShellDelete(domainname, recName, recType, content string) string {
text := fmt.Sprintf(`echo "DELETE %s %s %s"`, recType, recName, content)
text += "\r\n"
text += `Remove-DnsServerResourceRecord -Force -ComputerName "%s" -ZoneName "%s" -Name "%s" -RRType "%s" -RecordData "%s"`
text += "\r\n"
return fmt.Sprintf(text, c.adServer, domainname, recName, recType, content)
}
func (c *adProvider) createRec(domainname string, rec *models.RecordConfig) []*models.Correction {
arr := []*models.Correction{
{
Msg: fmt.Sprintf("CREATE record: %s %s ttl(%d) %s", rec.Name, rec.Type, rec.TTL, rec.Target),
F: func() error {
return powerShellDoCommand(c.generatePowerShellCreate(domainname, rec), true)
}},
}
return arr
}
func (c *adProvider) modifyRec(domainname string, m diff.Correlation) *models.Correction {
old, rec := m.Existing, m.Desired
return &models.Correction{
Msg: m.String(),
F: func() error {
return powerShellDoCommand(c.generatePowerShellModify(domainname, rec.Name, rec.Type, old.Target, rec.Target, old.TTL, rec.TTL), true)
},
}
}
func (c *adProvider) deleteRec(domainname string, rec *models.RecordConfig) *models.Correction {
return &models.Correction{
Msg: fmt.Sprintf("DELETE record: %s %s ttl(%d) %s", rec.Name, rec.Type, rec.TTL, rec.Target),
F: func() error {
return powerShellDoCommand(c.generatePowerShellDelete(domainname, rec.Name, rec.Type, rec.Target), true)
},
}
}