1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
// Package route53 implements a DNS provider for solving the DNS-01 challenge
// using AWS Route 53 DNS.
package route53
import (
"fmt"
"math/rand"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/client"
"github.com/aws/aws-sdk-go/aws/request"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/route53"
"github.com/xenolf/lego/acme"
)
const (
maxRetries = 5
route53TTL = 10
)
// DNSProvider implements the acme.ChallengeProvider interface
type DNSProvider struct {
client *route53.Route53
}
// customRetryer implements the client.Retryer interface by composing the
// DefaultRetryer. It controls the logic for retrying recoverable request
// errors (e.g. when rate limits are exceeded).
type customRetryer struct {
client.DefaultRetryer
}
// RetryRules overwrites the DefaultRetryer's method.
// It uses a basic exponential backoff algorithm that returns an initial
// delay of ~400ms with an upper limit of ~30 seconds which should prevent
// causing a high number of consecutive throttling errors.
// For reference: Route 53 enforces an account-wide(!) 5req/s query limit.
func (d customRetryer) RetryRules(r *request.Request) time.Duration {
retryCount := r.RetryCount
if retryCount > 7 {
retryCount = 7
}
delay := (1 << uint(retryCount)) * (rand.Intn(50) + 200)
return time.Duration(delay) * time.Millisecond
}
// NewDNSProvider returns a DNSProvider instance configured for the AWS
// Route 53 service.
//
// AWS Credentials are automatically detected in the following locations
// and prioritized in the following order:
// 1. Environment variables: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY,
// AWS_REGION, [AWS_SESSION_TOKEN]
// 2. Shared credentials file (defaults to ~/.aws/credentials)
// 3. Amazon EC2 IAM role
//
// See also: https://github.com/aws/aws-sdk-go/wiki/configuring-sdk
func NewDNSProvider() (*DNSProvider, error) {
r := customRetryer{}
r.NumMaxRetries = maxRetries
config := request.WithRetryer(aws.NewConfig(), r)
client := route53.New(session.New(config))
return &DNSProvider{client: client}, nil
}
// Present creates a TXT record using the specified parameters
func (r *DNSProvider) Present(domain, token, keyAuth string) error {
fqdn, value, _ := acme.DNS01Record(domain, keyAuth)
value = `"` + value + `"`
return r.changeRecord("UPSERT", fqdn, value, route53TTL)
}
// CleanUp removes the TXT record matching the specified parameters
func (r *DNSProvider) CleanUp(domain, token, keyAuth string) error {
fqdn, value, _ := acme.DNS01Record(domain, keyAuth)
value = `"` + value + `"`
return r.changeRecord("DELETE", fqdn, value, route53TTL)
}
func (r *DNSProvider) changeRecord(action, fqdn, value string, ttl int) error {
hostedZoneID, err := getHostedZoneID(fqdn, r.client)
if err != nil {
return fmt.Errorf("Failed to determine Route 53 hosted zone ID: %v", err)
}
recordSet := newTXTRecordSet(fqdn, value, ttl)
reqParams := &route53.ChangeResourceRecordSetsInput{
HostedZoneId: aws.String(hostedZoneID),
ChangeBatch: &route53.ChangeBatch{
Comment: aws.String("Managed by Lego"),
Changes: []*route53.Change{
{
Action: aws.String(action),
ResourceRecordSet: recordSet,
},
},
},
}
resp, err := r.client.ChangeResourceRecordSets(reqParams)
if err != nil {
return fmt.Errorf("Failed to change Route 53 record set: %v", err)
}
statusID := resp.ChangeInfo.Id
return acme.WaitFor(120*time.Second, 4*time.Second, func() (bool, error) {
reqParams := &route53.GetChangeInput{
Id: statusID,
}
resp, err := r.client.GetChange(reqParams)
if err != nil {
return false, fmt.Errorf("Failed to query Route 53 change status: %v", err)
}
if *resp.ChangeInfo.Status == route53.ChangeStatusInsync {
return true, nil
}
return false, nil
})
}
func getHostedZoneID(fqdn string, client *route53.Route53) (string, error) {
authZone, err := acme.FindZoneByFqdn(fqdn, acme.RecursiveNameservers)
if err != nil {
return "", err
}
// .DNSName should not have a trailing dot
reqParams := &route53.ListHostedZonesByNameInput{
DNSName: aws.String(acme.UnFqdn(authZone)),
}
resp, err := client.ListHostedZonesByName(reqParams)
if err != nil {
return "", err
}
var hostedZoneID string
for _, hostedZone := range resp.HostedZones {
// .Name has a trailing dot
if !*hostedZone.Config.PrivateZone && *hostedZone.Name == authZone {
hostedZoneID = *hostedZone.Id
break
}
}
if len(hostedZoneID) == 0 {
return "", fmt.Errorf("Zone %s not found in Route 53 for domain %s", authZone, fqdn)
}
if strings.HasPrefix(hostedZoneID, "/hostedzone/") {
hostedZoneID = strings.TrimPrefix(hostedZoneID, "/hostedzone/")
}
return hostedZoneID, nil
}
func newTXTRecordSet(fqdn, value string, ttl int) *route53.ResourceRecordSet {
return &route53.ResourceRecordSet{
Name: aws.String(fqdn),
Type: aws.String("TXT"),
TTL: aws.Int64(int64(ttl)),
ResourceRecords: []*route53.ResourceRecord{
{Value: aws.String(value)},
},
}
}
|
