forked from elliottsam/winrm-dns-client
/
dns.go
273 lines (248 loc) · 8.16 KB
/
dns.go
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package dns
import (
"fmt"
"strings"
)
// Record containing information regarding DNS record
type Record struct {
Dnszone string
Name string
Type string
Value string
TTL float64
ID string
NewValue string
NewTTL float64
}
// ReadRecords returns all DNS records matching query
func (c *Client) ReadRecords(rec Record) ([]Record, error) {
// powershell script template to read record from DNS
const tmplpscript = `
Get-DnsServerResourceRecord -ZoneName {{.Dnszone}}{{ if .Name }} -Name {{.Name}}{{end}} | ?{($_.RecordType -eq 'A' -or $_.RecordType -eq 'CNAME') -and $_.HostName -eq '{{ .Name }}'} | select DistinguishedName, HostName, RecordData, RecordType, TimeToLive | ConvertTo-Json
`
pscript, err := tmplExec(rec, tmplpscript)
if err != nil {
return []Record{}, fmt.Errorf("Creating template: %v", err)
}
output, err := c.ExecutePowerShellScript(pscript)
if err != nil {
return []Record{}, fmt.Errorf("Running PowerShell script: %v", err)
}
if output.stdout == "" {
return []Record{}, fmt.Errorf("No Record found: %v", rec.Name)
}
output.stdout = makeResponseArray(output.stdout)
resp, err := unmarshalResponse(output.stdout)
if err != nil {
return []Record{}, fmt.Errorf("Unmarshalling response: %v", err)
}
return *convertResponse(resp, rec), nil
}
// ReadRecord performs DNS Record lookup from server
func (c *Client) ReadRecord(rec Record) (Record, error) {
// powershell script template to read record from DNS
const tmplpscript = `
Get-DnsServerResourceRecord -ZoneName {{.Dnszone}}{{ if .Name }} -Name {{.Name}}{{end}} | ?{($_.RecordType -eq 'A' -or $_.RecordType -eq 'CNAME') -and $_.HostName -eq '{{ .Name }}'} | select DistinguishedName, HostName, RecordData, RecordType, TimeToLive | ConvertTo-Json
`
pscript, err := tmplExec(rec, tmplpscript)
if err != nil {
return Record{}, fmt.Errorf("Creating template: %v", err)
}
output, err := c.ExecutePowerShellScript(pscript)
if err != nil {
return Record{}, fmt.Errorf("Running PowerShell script: %v", err)
}
if output.stdout == "" {
return Record{}, fmt.Errorf("No Record found: %v", rec.Name)
}
output.stdout = makeResponseArray(output.stdout)
resp, err := unmarshalResponse(output.stdout)
if err != nil {
return Record{}, fmt.Errorf("Unmarshalling response: %v", err)
}
for _, v := range *convertResponse(resp, rec) {
if v.Value == rec.Value {
return v, nil
}
}
return Record{}, fmt.Errorf("Record not found: %s", rec.Name)
}
// ReadRecordfromID retrieves specifc DNS record based on record ID
func (c *Client) ReadRecordfromID(recID string) (Record, error) {
id := strings.Split(recID, "|")
if len(id) != 3 {
return Record{}, fmt.Errorf("ID is incorrect")
}
rec := Record{
Dnszone: id[0],
Name: id[1],
Value: id[2],
}
result, err := c.ReadRecords(rec)
if err != nil {
return Record{}, fmt.Errorf("Reading record: %v", err)
}
for _, v := range result {
if v.ID == recID {
return v, nil
}
}
return Record{}, fmt.Errorf("Record not found: %v", recID)
}
// CreateRecord creates new DNS records on server
func (c *Client) CreateRecord(rec Record) ([]Record, error) {
const tmplscriptA = `
Add-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }} -A -IPv4Address {{ .Value }} -TimeToLive (New-TimeSpan -Seconds {{ .TTL }})
`
const tmplscriptCname = `
Add-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }} -CName -HostNameAlias {{ .Value }} -TimeToLive (New-TimeSpan -Seconds {{ .TTL }})
`
var (
pscript string
err error
)
if c.RecordExist(rec) {
return []Record{}, fmt.Errorf("Record already exists: %v", rec)
}
rec.ID = fmt.Sprintf("%s|%s|%s", rec.Dnszone, rec.Name, rec.Value)
switch rec.Type {
case "A":
pscript, err = tmplExec(rec, tmplscriptA)
if err != nil {
return []Record{}, fmt.Errorf("Creating template: %v", err)
}
case "CNAME":
pscript, err = tmplExec(rec, tmplscriptCname)
if err != nil {
return []Record{}, fmt.Errorf("Creating template: %v", err)
}
}
_, err = c.ExecutePowerShellScript(pscript)
if err != nil {
return []Record{}, fmt.Errorf("Executing PowerShell script: %v", err)
}
record, err := c.ReadRecordfromID(rec.ID)
if err != nil {
return []Record{}, fmt.Errorf("Reading record: %v", err)
}
var result []Record
result = append(result, record)
return result, nil
}
// DeleteRecord deletes DNS record specified
func (c *Client) DeleteRecord(rec Record) error {
const tmplscriptA string = `
(Get-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }}) | ?{$_.HostName -eq '{{ .Name }}' -and $_.RecordData.IPv4Address -match '{{ .Value }}'} | Remove-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Force
`
const tmplscriptCname string = `
(Get-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }}) | ?{$_.HostName -eq '{{ .Name }}' -and $_.RecordData.HostNameAlias -match '{{ .Value }}'} | Remove-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Force
`
var (
pscript string
err error
)
if !c.RecordExist(rec) {
return fmt.Errorf("Record not found: %v", rec)
}
switch rec.Type {
case "A":
pscript, err = tmplExec(rec, tmplscriptA)
if err != nil {
return fmt.Errorf("Creating template: %v", err)
}
case "CNAME":
pscript, err = tmplExec(rec, tmplscriptCname)
if err != nil {
return fmt.Errorf("Creating template: %v", err)
}
}
_, err = c.ExecutePowerShellScript(pscript)
if err != nil {
return fmt.Errorf("Executing PowerShell script: %v", err)
}
return nil
}
// UpdateRecord updates an existing DNS record
func (c *Client) UpdateRecord(rec Record, newValue string, newTTL float64) (Record, error) {
const tmplscriptA string = `
$old = Get-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }} | ?{$_.HostName -eq '{{ .Name }}' -and $_.RecordData.IPv4Address -eq '{{ .Value }}'}
$new = Get-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }} | ?{$_.HostName -eq '{{ .Name }}' -and $_.RecordData.IPv4Address -eq '{{ .Value }}'}
{{ if .NewValue -}}
$new.RecordData.IPv4Address = [System.Net.IPAddress]::Parse('{{ .NewValue }}')
{{ end -}}
{{ if ne .NewTTL 0.0 -}}
$new.TimeToLive = New-Timespan -Seconds {{ .NewTTL }}
{{ end -}}
Set-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -NewInputObject $new -OldInputObject $old
`
const tmplscriptCname string = `
$old = Get-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }} | ?{$_.HostName -eq '{{ .Name }}' -and $_.RecordData.HostNameAlias -eq '{{ .Value }}'}
$new = Get-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -Name {{ .Name }} | ?{$_.HostName -eq '{{ .Name }}' -and $_.RecordData.HostNameAlias -eq '{{ .Value }}'}
{{ if .NewValue -}}
$new.RecordData.HostNameAlias = '{{ .NewValue }}'
{{ end -}}
{{ if ne .NewTTL 0.0 -}}
$new.TimeToLive = New-Timespan -Seconds {{ .NewTTL }}
{{ end -}}
Set-DnsServerResourceRecord -ZoneName {{ .Dnszone }} -NewInputObject $new -OldInputObject $old
`
var (
pscript string
err error
)
if !c.RecordExist(rec) {
return Record{}, fmt.Errorf("Record not found: %v", rec.Name)
}
rec, err = c.ReadRecord(rec)
if err != nil {
return Record{}, fmt.Errorf("Reading record: %v", err)
}
rec.NewValue = newValue
rec.NewTTL = newTTL
switch rec.Type {
case "A":
pscript, err = tmplExec(rec, tmplscriptA)
if err != nil {
return Record{}, fmt.Errorf("Createing template: %v", err)
}
case "CNAME":
pscript, err = tmplExec(rec, tmplscriptCname)
if err != nil {
return Record{}, fmt.Errorf("Createing template: %v", err)
}
}
_, err = c.ExecutePowerShellScript(pscript)
if err != nil {
return Record{}, fmt.Errorf("Excuting PowerShell script: %v", err)
}
if rec.NewValue != "" {
rec.Value = rec.NewValue
}
rec, err = c.ReadRecord(rec)
if err != nil {
return Record{}, fmt.Errorf("Reading updated record: %v", err)
}
return rec, nil
}
// RecordExist returns if record exists or not
func (c *Client) RecordExist(rec Record) bool {
var records []Record
if rec.ID != "" {
rec.Value = strings.Split(rec.ID, "|")[2]
resp, err := c.ReadRecordfromID(rec.ID)
if err != nil {
return false
}
records = append(records, resp)
} else {
records, _ = c.ReadRecords(rec)
}
if len(records) > 0 {
for _, v := range records {
if v.Value == rec.Value {
return true
}
}
}
return false
}