dnscontrol/providers/linode/linodeProvider.go
2024-07-10 15:53:50 -04:00

350 lines
9.5 KiB
Go

package linode
import (
"context"
"encoding/json"
"fmt"
"net/http"
"net/url"
"regexp"
"strings"
"github.com/StackExchange/dnscontrol/v4/models"
"github.com/StackExchange/dnscontrol/v4/pkg/diff"
"github.com/StackExchange/dnscontrol/v4/providers"
"github.com/miekg/dns/dnsutil"
"golang.org/x/oauth2"
)
/*
Linode API DNS provider:
Info required in `creds.json`:
- token
*/
// Allowed values from the Linode API
// https://www.linode.com/docs/api/domains/#domains-list__responses
var allowedTTLValues = []uint32{
0, // Default, currently 1209600 seconds
300, // 5 minutes
3600, // 1 hour
7200, // 2 hours
14400, // 4 hours
28800, // 8 hours
57600, // 16 hours
86400, // 1 day
172800, // 2 days
345600, // 4 days
604800, // 1 week
1209600, // 2 weeks
2419200, // 4 weeks
}
var srvRegexp = regexp.MustCompile(`^_(?P<Service>\w+)\.\_(?P<Protocol>\w+)$`)
// linodeProvider is the handle for this provider.
type linodeProvider struct {
client *http.Client
baseURL *url.URL
domainIndex map[string]int
}
var defaultNameServerNames = []string{
"ns1.linode.com",
"ns2.linode.com",
"ns3.linode.com",
"ns4.linode.com",
"ns5.linode.com",
}
// NewLinode creates the provider.
func NewLinode(m map[string]string, metadata json.RawMessage) (providers.DNSServiceProvider, error) {
if m["token"] == "" {
return nil, fmt.Errorf("missing Linode token")
}
ctx := context.Background()
client := oauth2.NewClient(
ctx,
oauth2.StaticTokenSource(&oauth2.Token{AccessToken: m["token"]}),
)
baseURL, err := url.Parse(defaultBaseURL)
if err != nil {
return nil, fmt.Errorf("invalid base URL for Linode")
}
api := &linodeProvider{client: client, baseURL: baseURL}
// Get a domain to validate the token
if err := api.fetchDomainList(); err != nil {
return nil, err
}
return api, nil
}
var features = providers.DocumentationNotes{
// The default for unlisted capabilities is 'Cannot'.
// See providers/capabilities.go for the entire list of capabilities.
providers.CanGetZones: providers.Can(),
providers.CanConcur: providers.Cannot(),
providers.CanUseCAA: providers.Can("Linode doesn't support changing the CAA flag"),
providers.CanUseLOC: providers.Cannot(),
providers.DocDualHost: providers.Cannot(),
providers.DocOfficiallySupported: providers.Cannot(),
}
func init() {
const providerName = "LINODE"
const providerMaintainer = "@koesie10"
// SRV support is in this provider, but Linode doesn't seem to support it properly
fns := providers.DspFuncs{
Initializer: NewLinode,
RecordAuditor: AuditRecords,
}
providers.RegisterDomainServiceProviderType(providerName, fns, features)
providers.RegisterMaintainer(providerName, providerMaintainer)
}
// GetNameservers returns the nameservers for a domain.
func (api *linodeProvider) GetNameservers(domain string) ([]*models.Nameserver, error) {
return models.ToNameservers(defaultNameServerNames)
}
// GetZoneRecords gets the records of a zone and returns them in RecordConfig format.
func (api *linodeProvider) GetZoneRecords(domain string, meta map[string]string) (models.Records, error) {
if api.domainIndex == nil {
if err := api.fetchDomainList(); err != nil {
return nil, err
}
}
domainID, ok := api.domainIndex[domain]
if !ok {
return nil, fmt.Errorf("'%s' not a zone in Linode account", domain)
}
return api.getRecordsForDomain(domainID, domain)
}
// GetZoneRecordsCorrections returns a list of corrections that will turn existing records into dc.Records.
func (api *linodeProvider) GetZoneRecordsCorrections(dc *models.DomainConfig, existingRecords models.Records) ([]*models.Correction, error) {
// Linode doesn't allow selecting an arbitrary TTL, only a set of predefined values
// We need to make sure we don't change it every time if it is as close as it's going to get
// The documentation says that it will always round up to the next highest value: 300 -> 300, 301 -> 3600.
// https://www.linode.com/docs/api/domains/#domains-list__responses
for _, record := range dc.Records {
record.TTL = fixTTL(record.TTL)
}
if api.domainIndex == nil {
if err := api.fetchDomainList(); err != nil {
return nil, err
}
}
domainID, ok := api.domainIndex[dc.Name]
if !ok {
return nil, fmt.Errorf("'%s' not a zone in Linode account", dc.Name)
}
toReport, create, del, modify, err := diff.NewCompat(dc).IncrementalDiff(existingRecords)
if err != nil {
return nil, err
}
// Start corrections with the reports
corrections := diff.GenerateMessageCorrections(toReport)
// Deletes first so changing type works etc.
for _, m := range del {
id := m.Existing.Original.(*domainRecord).ID
if id == 0 { // Skip ID 0, these are the default nameservers always present
continue
}
corr := &models.Correction{
Msg: fmt.Sprintf("%s, Linode ID: %d", m.String(), id),
F: func() error {
return api.deleteRecord(domainID, id)
},
}
corrections = append(corrections, corr)
}
for _, m := range create {
req, err := toReq(dc, m.Desired)
if err != nil {
return nil, err
}
j, err := json.Marshal(req)
if err != nil {
return nil, err
}
corr := &models.Correction{
Msg: fmt.Sprintf("%s: %s", m.String(), string(j)),
F: func() error {
record, err := api.createRecord(domainID, req)
if err != nil {
return err
}
// TTL isn't saved when creating a record, so we will need to modify it immediately afterwards
return api.modifyRecord(domainID, record.ID, req)
},
}
corrections = append(corrections, corr)
}
for _, m := range modify {
id := m.Existing.Original.(*domainRecord).ID
if id == 0 { // Skip ID 0, these are the default nameservers always present
continue
}
req, err := toReq(dc, m.Desired)
if err != nil {
return nil, err
}
j, err := json.Marshal(req)
if err != nil {
return nil, err
}
corr := &models.Correction{
Msg: fmt.Sprintf("%s, Linode ID: %d: %s", m.String(), id, string(j)),
F: func() error {
return api.modifyRecord(domainID, id, req)
},
}
corrections = append(corrections, corr)
}
return corrections, nil
}
func (api *linodeProvider) getRecordsForDomain(domainID int, domain string) (models.Records, error) {
records, err := api.getRecords(domainID)
if err != nil {
return nil, err
}
existingRecords := make([]*models.RecordConfig, len(records), len(records)+len(defaultNameServerNames))
for i := range records {
existingRecords[i] = toRc(domain, &records[i])
}
// Linode always has read-only NS servers, but these are not mentioned in the API response
// https://github.com/linode/manager/blob/edd99dc4e1be5ab8190f243c3dbf8b830716255e/src/constants.js#L184
for _, name := range defaultNameServerNames {
rc := &models.RecordConfig{
Type: "NS",
Original: &domainRecord{},
}
rc.SetLabelFromFQDN(domain, domain)
rc.SetTarget(name)
existingRecords = append(existingRecords, rc)
}
return existingRecords, nil
}
func toRc(domain string, r *domainRecord) *models.RecordConfig {
rc := &models.RecordConfig{
Type: r.Type,
TTL: r.TTLSec,
MxPreference: r.Priority,
SrvPriority: r.Priority,
SrvWeight: r.Weight,
SrvPort: r.Port,
CaaTag: r.Tag,
Original: r,
}
rc.SetLabel(r.Name, domain)
switch rtype := r.Type; rtype { // #rtype_variations
case "CNAME", "MX", "NS", "SRV":
rc.SetTarget(dnsutil.AddOrigin(r.Target+".", domain))
case "CAA":
// Linode doesn't support CAA flags and just returns the tag and value separately
rc.SetTarget(r.Target)
default:
rc.PopulateFromString(r.Type, r.Target, domain)
}
return rc
}
func toReq(dc *models.DomainConfig, rc *models.RecordConfig) (*recordEditRequest, error) {
req := &recordEditRequest{
Type: rc.Type,
Name: rc.GetLabel(),
Target: rc.GetTargetField(),
TTL: int(rc.TTL),
Priority: 0,
Port: int(rc.SrvPort),
Weight: int(rc.SrvWeight),
}
// Linode doesn't use "@", it uses an empty name
if req.Name == "@" {
req.Name = ""
}
// Linode uses the same property for MX and SRV priority
switch rc.Type { // #rtype_variations
case "A", "AAAA", "NS", "PTR", "TXT", "SOA", "TLSA":
// Nothing special.
case "MX":
req.Priority = int(rc.MxPreference)
req.Target = fixTarget(req.Target, dc.Name)
// Linode doesn't use "." for a null MX record, it uses an empty name
if req.Target == "." {
req.Target = ""
}
case "SRV":
req.Priority = int(rc.SrvPriority)
// From softlayer provider
// This is to support SRV, it doesn't work yet for Linode
result := srvRegexp.FindStringSubmatch(req.Name)
if len(result) != 3 {
return nil, fmt.Errorf("SRV Record must match format \"_service._protocol\" not %s", req.Name)
}
var serviceName, protocol = result[1], strings.ToLower(result[2])
req.Protocol = protocol
req.Service = serviceName
req.Name = ""
case "CNAME":
req.Target = fixTarget(req.Target, dc.Name)
case "CAA":
req.Tag = rc.CaaTag
default:
return nil, fmt.Errorf("linode.toReq rtype %q unimplemented", rc.Type)
}
return req, nil
}
func fixTarget(target, domain string) string {
// Linode always wants a fully qualified target name
if target[len(target)-1] == '.' {
return target[:len(target)-1]
}
return fmt.Sprintf("%s.%s", target, domain)
}
func fixTTL(ttl uint32) uint32 {
// if the TTL is larger than the largest allowed value, return the largest allowed value
if ttl > allowedTTLValues[len(allowedTTLValues)-1] {
return allowedTTLValues[len(allowedTTLValues)-1]
}
for _, v := range allowedTTLValues {
if v >= ttl {
return v
}
}
return allowedTTLValues[0]
}