Files
lego/providers/dns/edgedns/edgedns.go
2026-01-22 18:23:59 +01:00

315 lines
8.3 KiB
Go

// Package edgedns replaces fastdns, implementing a DNS provider for solving the DNS-01 challenge using Akamai EdgeDNS.
package edgedns
import (
"context"
"errors"
"fmt"
"net/http"
"slices"
"strings"
"time"
edgegriddns "github.com/akamai/AkamaiOPEN-edgegrid-golang/v11/pkg/dns"
"github.com/akamai/AkamaiOPEN-edgegrid-golang/v11/pkg/edgegrid"
"github.com/akamai/AkamaiOPEN-edgegrid-golang/v11/pkg/session"
"github.com/go-acme/lego/v5/challenge"
"github.com/go-acme/lego/v5/challenge/dns01"
"github.com/go-acme/lego/v5/platform/config/env"
)
// Environment variables names.
const (
envNamespace = "AKAMAI_"
EnvEdgeRc = envNamespace + "EDGERC"
EnvEdgeRcSection = envNamespace + "EDGERC_SECTION"
EnvAccountSwitchKey = envNamespace + "ACCOUNT_SWITCH_KEY"
EnvTTL = envNamespace + "TTL"
EnvPropagationTimeout = envNamespace + "PROPAGATION_TIMEOUT"
EnvPollingInterval = envNamespace + "POLLING_INTERVAL"
)
// Managed by the Akamai EdgeGrid client.
// The constants are only helpers.
const (
EnvHost = envNamespace + "HOST"
EnvClientToken = envNamespace + "CLIENT_TOKEN"
EnvClientSecret = envNamespace + "CLIENT_SECRET"
EnvAccessToken = envNamespace + "ACCESS_TOKEN"
)
const (
defaultPropagationTimeout = 3 * time.Minute
defaultPollInterval = 15 * time.Second
)
const maxBody = 131072
var _ challenge.ProviderTimeout = (*DNSProvider)(nil)
// Config is used to configure the creation of the DNSProvider.
type Config struct {
*edgegrid.Config
PropagationTimeout time.Duration
PollingInterval time.Duration
TTL int
}
// NewDefaultConfig returns a default configuration for the DNSProvider.
func NewDefaultConfig() *Config {
return &Config{
TTL: env.GetOrDefaultInt(EnvTTL, dns01.DefaultTTL),
PropagationTimeout: env.GetOrDefaultSecond(EnvPropagationTimeout, defaultPropagationTimeout),
PollingInterval: env.GetOrDefaultSecond(EnvPollingInterval, defaultPollInterval),
Config: &edgegrid.Config{MaxBody: maxBody},
}
}
// DNSProvider implements the challenge.Provider interface.
type DNSProvider struct {
config *Config
}
// NewDNSProvider returns a DNSProvider instance configured for Akamai EdgeDNS:
// Akamai's credentials are automatically detected in the following locations and prioritized in the following order:
//
// 1. Section-specific environment variables `AKAMAI_{SECTION}_HOST`, `AKAMAI_{SECTION}_ACCESS_TOKEN`, `AKAMAI_{SECTION}_CLIENT_TOKEN`, `AKAMAI_{SECTION}_CLIENT_SECRET` where `{SECTION}` is specified using `AKAMAI_EDGERC_SECTION`
// 2. If `AKAMAI_EDGERC_SECTION` is not defined or is set to `default`: Environment variables `AKAMAI_HOST`, `AKAMAI_ACCESS_TOKEN`, `AKAMAI_CLIENT_TOKEN`, `AKAMAI_CLIENT_SECRET`
// 3. .edgerc file located at `AKAMAI_EDGERC` (defaults to `~/.edgerc`, sections can be specified using `AKAMAI_EDGERC_SECTION`)
//
// See also: https://developer.akamai.com/api/getting-started
func NewDNSProvider() (*DNSProvider, error) {
conf, err := edgegrid.New(
edgegrid.WithEnv(true),
edgegrid.WithFile(env.GetOrDefaultString(EnvEdgeRc, "~/.edgerc")),
edgegrid.WithSection(env.GetOrDefaultString(EnvEdgeRcSection, "default")),
)
if err != nil {
return nil, fmt.Errorf("edgedns: %w", err)
}
conf.MaxBody = maxBody
accountSwitchKey := env.GetOrDefaultString(EnvAccountSwitchKey, "")
if accountSwitchKey != "" {
conf.AccountKey = accountSwitchKey
}
config := NewDefaultConfig()
config.Config = conf
return NewDNSProviderConfig(config)
}
// NewDNSProviderConfig return a DNSProvider instance configured for EdgeDNS.
func NewDNSProviderConfig(config *Config) (*DNSProvider, error) {
if config == nil {
return nil, errors.New("edgedns: the configuration of the DNS provider is nil")
}
err := config.Validate()
if err != nil {
return nil, fmt.Errorf("edgedns: %w", err)
}
return &DNSProvider{config: config}, nil
}
// Timeout returns the timeout and interval to use when checking for DNS propagation.
// Adjusting here to cope with spikes in propagation times.
func (d *DNSProvider) Timeout() (timeout, interval time.Duration) {
return d.config.PropagationTimeout, d.config.PollingInterval
}
// Present creates a TXT record to fulfill the dns-01 challenge.
func (d *DNSProvider) Present(ctx context.Context, domain, token, keyAuth string) error {
info := dns01.GetChallengeInfo(ctx, domain, keyAuth)
sess, err := session.New(session.WithSigner(d.config))
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
client := edgegriddns.Client(sess)
zone, err := getZone(ctx, info.EffectiveFQDN)
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
record, err := client.GetRecord(ctx, edgegriddns.GetRecordRequest{
Zone: zone,
Name: info.EffectiveFQDN,
RecordType: "TXT",
})
if err != nil && !isNotFound(err) {
return fmt.Errorf("edgedns: %w", err)
}
if err == nil && record == nil {
return errors.New("edgedns: unknown error")
}
if record != nil {
if containsValue(record.Target, info.Value) {
// have a record and have entry already
return nil
}
record.Target = append(record.Target, `"`+info.Value+`"`)
record.TTL = d.config.TTL
err = client.UpdateRecord(ctx, edgegriddns.UpdateRecordRequest{
Record: &edgegriddns.RecordBody{
Name: record.Name,
RecordType: record.RecordType,
TTL: record.TTL,
Active: record.Active,
Target: record.Target,
},
Zone: zone,
})
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
return nil
}
err = client.CreateRecord(ctx, edgegriddns.CreateRecordRequest{
Record: &edgegriddns.RecordBody{
Name: info.EffectiveFQDN,
RecordType: "TXT",
TTL: d.config.TTL,
Target: []string{`"` + info.Value + `"`},
},
Zone: zone,
RecLock: nil,
})
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
return nil
}
// CleanUp removes the record matching the specified parameters.
func (d *DNSProvider) CleanUp(ctx context.Context, domain, token, keyAuth string) error {
info := dns01.GetChallengeInfo(ctx, domain, keyAuth)
sess, err := session.New(session.WithSigner(d.config))
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
client := edgegriddns.Client(sess)
zone, err := getZone(ctx, info.EffectiveFQDN)
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
existingRec, err := client.GetRecord(ctx, edgegriddns.GetRecordRequest{
Zone: zone,
Name: info.EffectiveFQDN,
RecordType: "TXT",
})
if err != nil {
if isNotFound(err) {
return nil
}
return fmt.Errorf("edgedns: %w", err)
}
if existingRec == nil {
return errors.New("edgedns: unknown failure")
}
if len(existingRec.Target) == 0 {
return errors.New("edgedns: TXT record is invalid")
}
if !containsValue(existingRec.Target, info.Value) {
return nil
}
newRData := filterRData(existingRec, info)
if len(newRData) > 0 {
existingRec.Target = newRData
err = client.UpdateRecord(ctx, edgegriddns.UpdateRecordRequest{
Record: &edgegriddns.RecordBody{
Name: existingRec.Name,
RecordType: existingRec.RecordType,
TTL: existingRec.TTL,
Active: existingRec.Active,
Target: existingRec.Target,
},
Zone: zone,
})
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
return nil
}
err = client.DeleteRecord(ctx, edgegriddns.DeleteRecordRequest{
Zone: zone,
Name: existingRec.Name,
RecordType: "TXT",
RecLock: nil,
})
if err != nil {
return fmt.Errorf("edgedns: %w", err)
}
return nil
}
func getZone(ctx context.Context, domain string) (string, error) {
zone, err := dns01.DefaultClient().FindZoneByFqdn(ctx, domain)
if err != nil {
return "", fmt.Errorf("could not find zone for FQDN %q: %w", domain, err)
}
return dns01.UnFqdn(zone), nil
}
func containsValue(values []string, value string) bool {
return slices.ContainsFunc(values, func(val string) bool {
return strings.Trim(val, `"`) == value
})
}
func isNotFound(err error) bool {
if err == nil {
return false
}
var e *edgegriddns.Error
return errors.As(err, &e) && e.StatusCode == http.StatusNotFound
}
func filterRData(existingRec *edgegriddns.GetRecordResponse, info dns01.ChallengeInfo) []string {
var newRData []string
for _, val := range existingRec.Target {
val = strings.Trim(val, `"`)
if val == info.Value {
continue
}
newRData = append(newRData, val)
}
return newRData
}