Fix: Add TTL and custom Timeout in DigitalOcean DNS provider

vendor/github.com/xenolf/lego/providers/dns/lightsail/lightsail.go

@@ -0,0 +1,107 @@
+// Package lightsail implements a DNS provider for solving the DNS-01 challenge
+// using AWS Lightsail DNS.
+package lightsail
+
+import (
+	"math/rand"
+	"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/lightsail"
+	"github.com/xenolf/lego/acmev2"
+)
+
+const (
+	maxRetries = 5
+)
+
+// DNSProvider implements the acmev2.ChallengeProvider interface
+type DNSProvider struct {
+	client *lightsail.Lightsail
+}
+
+// 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
+// Lightsail 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_SESSION_TOKEN], [DNS_ZONE]
+// 2. Shared credentials file (defaults to ~/.aws/credentials)
+// 3. Amazon EC2 IAM role
+//
+// public hosted zone via the FQDN.
+//
+// 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 := lightsail.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, _ := acmev2.DNS01Record(domain, keyAuth)
+	value = `"` + value + `"`
+	err := r.newTxtRecord(domain, fqdn, value)
+	return err
+}
+
+// CleanUp removes the TXT record matching the specified parameters
+func (r *DNSProvider) CleanUp(domain, token, keyAuth string) error {
+	fqdn, value, _ := acmev2.DNS01Record(domain, keyAuth)
+	value = `"` + value + `"`
+	params := &lightsail.DeleteDomainEntryInput{
+		DomainName: aws.String(domain),
+		DomainEntry: &lightsail.DomainEntry{
+			Name:   aws.String(fqdn),
+			Type:   aws.String("TXT"),
+			Target: aws.String(value),
+		},
+	}
+	_, err := r.client.DeleteDomainEntry(params)
+	return err
+}
+
+func (r *DNSProvider) newTxtRecord(domain string, fqdn string, value string) error {
+	params := &lightsail.CreateDomainEntryInput{
+		DomainName: aws.String(domain),
+		DomainEntry: &lightsail.DomainEntry{
+			Name:   aws.String(fqdn),
+			Target: aws.String(value),
+			Type:   aws.String("TXT"),
+		},
+	}
+	_, err := r.client.CreateDomainEntry(params)
+	return err
+}