Add DNS provider for Dynu. (#1081)

README.md

@@ -50,17 +50,17 @@ Detailed documentation is available [here](https://go-acme.github.io/lego/dns).
 | [Checkdomain](https://go-acme.github.io/lego/dns/checkdomain/)                  | [Cloudflare](https://go-acme.github.io/lego/dns/cloudflare/)                    | [ClouDNS](https://go-acme.github.io/lego/dns/cloudns/)                          | [CloudXNS](https://go-acme.github.io/lego/dns/cloudxns/)                        |
 | [ConoHa](https://go-acme.github.io/lego/dns/conoha/)                            | [Constellix](https://go-acme.github.io/lego/dns/constellix/)                    | [Designate DNSaaS for Openstack](https://go-acme.github.io/lego/dns/designate/) | [Digital Ocean](https://go-acme.github.io/lego/dns/digitalocean/)               |
 | [DNS Made Easy](https://go-acme.github.io/lego/dns/dnsmadeeasy/)                | [DNSimple](https://go-acme.github.io/lego/dns/dnsimple/)                        | [DNSPod](https://go-acme.github.io/lego/dns/dnspod/)                            | [Domain Offensive (do.de)](https://go-acme.github.io/lego/dns/dode/)            |
-| [DreamHost](https://go-acme.github.io/lego/dns/dreamhost/)                      | [Duck DNS](https://go-acme.github.io/lego/dns/duckdns/)                         | [Dyn](https://go-acme.github.io/lego/dns/dyn/)                                  | [EasyDNS](https://go-acme.github.io/lego/dns/easydns/)                          |
+| [DreamHost](https://go-acme.github.io/lego/dns/dreamhost/)                      | [Duck DNS](https://go-acme.github.io/lego/dns/duckdns/)                         | [Dyn](https://go-acme.github.io/lego/dns/dyn/)                                  | [Dynu](https://go-acme.github.io/lego/dns/dynu/)                                |
-| [Exoscale](https://go-acme.github.io/lego/dns/exoscale/)                        | [External program](https://go-acme.github.io/lego/dns/exec/)                    | [FastDNS](https://go-acme.github.io/lego/dns/fastdns/)                          | [Gandi Live DNS (v5)](https://go-acme.github.io/lego/dns/gandiv5/)              |
+| [EasyDNS](https://go-acme.github.io/lego/dns/easydns/)                          | [Exoscale](https://go-acme.github.io/lego/dns/exoscale/)                        | [External program](https://go-acme.github.io/lego/dns/exec/)                    | [FastDNS](https://go-acme.github.io/lego/dns/fastdns/)                          |
-| [Gandi](https://go-acme.github.io/lego/dns/gandi/)                              | [Glesys](https://go-acme.github.io/lego/dns/glesys/)                            | [Go Daddy](https://go-acme.github.io/lego/dns/godaddy/)                         | [Google Cloud](https://go-acme.github.io/lego/dns/gcloud/)                      |
+| [Gandi Live DNS (v5)](https://go-acme.github.io/lego/dns/gandiv5/)              | [Gandi](https://go-acme.github.io/lego/dns/gandi/)                              | [Glesys](https://go-acme.github.io/lego/dns/glesys/)                            | [Go Daddy](https://go-acme.github.io/lego/dns/godaddy/)                         |
-| [Hosting.de](https://go-acme.github.io/lego/dns/hostingde/)                     | [HTTP request](https://go-acme.github.io/lego/dns/httpreq/)                     | [Internet Initiative Japan](https://go-acme.github.io/lego/dns/iij/)            | [INWX](https://go-acme.github.io/lego/dns/inwx/)                                |
+| [Google Cloud](https://go-acme.github.io/lego/dns/gcloud/)                      | [Hosting.de](https://go-acme.github.io/lego/dns/hostingde/)                     | [HTTP request](https://go-acme.github.io/lego/dns/httpreq/)                     | [Internet Initiative Japan](https://go-acme.github.io/lego/dns/iij/)            |
-| [Joker](https://go-acme.github.io/lego/dns/joker/)                              | [Joohoi's ACME-DNS](https://go-acme.github.io/lego/dns/acme-dns/)               | [Linode (deprecated)](https://go-acme.github.io/lego/dns/linode/)               | [Linode (v4)](https://go-acme.github.io/lego/dns/linodev4/)                     |
+| [INWX](https://go-acme.github.io/lego/dns/inwx/)                                | [Joker](https://go-acme.github.io/lego/dns/joker/)                              | [Joohoi's ACME-DNS](https://go-acme.github.io/lego/dns/acme-dns/)               | [Linode (deprecated)](https://go-acme.github.io/lego/dns/linode/)               |
-| [Liquid Web](https://go-acme.github.io/lego/dns/liquidweb/)                     | [Manual](https://go-acme.github.io/lego/dns/manual/)                            | [MyDNS.jp](https://go-acme.github.io/lego/dns/mydnsjp/)                         | [Name.com](https://go-acme.github.io/lego/dns/namedotcom/)                      |
+| [Linode (v4)](https://go-acme.github.io/lego/dns/linodev4/)                     | [Liquid Web](https://go-acme.github.io/lego/dns/liquidweb/)                     | [Manual](https://go-acme.github.io/lego/dns/manual/)                            | [MyDNS.jp](https://go-acme.github.io/lego/dns/mydnsjp/)                         |
-| [Namecheap](https://go-acme.github.io/lego/dns/namecheap/)                      | [Namesilo](https://go-acme.github.io/lego/dns/namesilo/)                        | [Netcup](https://go-acme.github.io/lego/dns/netcup/)                            | [NIFCloud](https://go-acme.github.io/lego/dns/nifcloud/)                        |
+| [Name.com](https://go-acme.github.io/lego/dns/namedotcom/)                      | [Namecheap](https://go-acme.github.io/lego/dns/namecheap/)                      | [Namesilo](https://go-acme.github.io/lego/dns/namesilo/)                        | [Netcup](https://go-acme.github.io/lego/dns/netcup/)                            |
-| [NS1](https://go-acme.github.io/lego/dns/ns1/)                                  | [Open Telekom Cloud](https://go-acme.github.io/lego/dns/otc/)                   | [Oracle Cloud](https://go-acme.github.io/lego/dns/oraclecloud/)                 | [OVH](https://go-acme.github.io/lego/dns/ovh/)                                  |
+| [NIFCloud](https://go-acme.github.io/lego/dns/nifcloud/)                        | [NS1](https://go-acme.github.io/lego/dns/ns1/)                                  | [Open Telekom Cloud](https://go-acme.github.io/lego/dns/otc/)                   | [Oracle Cloud](https://go-acme.github.io/lego/dns/oraclecloud/)                 |
-| [PowerDNS](https://go-acme.github.io/lego/dns/pdns/)                            | [Rackspace](https://go-acme.github.io/lego/dns/rackspace/)                      | [reg.ru](https://go-acme.github.io/lego/dns/regru/)                             | [RFC2136](https://go-acme.github.io/lego/dns/rfc2136/)                          |
+| [OVH](https://go-acme.github.io/lego/dns/ovh/)                                  | [PowerDNS](https://go-acme.github.io/lego/dns/pdns/)                            | [Rackspace](https://go-acme.github.io/lego/dns/rackspace/)                      | [reg.ru](https://go-acme.github.io/lego/dns/regru/)                             |
-| [Sakura Cloud](https://go-acme.github.io/lego/dns/sakuracloud/)                 | [Scaleway](https://go-acme.github.io/lego/dns/scaleway/)                        | [Selectel](https://go-acme.github.io/lego/dns/selectel/)                        | [Servercow](https://go-acme.github.io/lego/dns/servercow/)                      |
+| [RFC2136](https://go-acme.github.io/lego/dns/rfc2136/)                          | [Sakura Cloud](https://go-acme.github.io/lego/dns/sakuracloud/)                 | [Scaleway](https://go-acme.github.io/lego/dns/scaleway/)                        | [Selectel](https://go-acme.github.io/lego/dns/selectel/)                        |
-| [Stackpath](https://go-acme.github.io/lego/dns/stackpath/)                      | [TransIP](https://go-acme.github.io/lego/dns/transip/)                          | [VegaDNS](https://go-acme.github.io/lego/dns/vegadns/)                          | [Versio.[nl/eu/uk]](https://go-acme.github.io/lego/dns/versio/)                 |
+| [Servercow](https://go-acme.github.io/lego/dns/servercow/)                      | [Stackpath](https://go-acme.github.io/lego/dns/stackpath/)                      | [TransIP](https://go-acme.github.io/lego/dns/transip/)                          | [VegaDNS](https://go-acme.github.io/lego/dns/vegadns/)                          |
-| [Vscale](https://go-acme.github.io/lego/dns/vscale/)                            | [Vultr](https://go-acme.github.io/lego/dns/vultr/)                              | [Zone.ee](https://go-acme.github.io/lego/dns/zoneee/)                           |                                                                                 |
+| [Versio.[nl/eu/uk]](https://go-acme.github.io/lego/dns/versio/)                 | [Vscale](https://go-acme.github.io/lego/dns/vscale/)                            | [Vultr](https://go-acme.github.io/lego/dns/vultr/)                              | [Zone.ee](https://go-acme.github.io/lego/dns/zoneee/)                           |
 
 <!-- END DNS PROVIDERS LIST -->

cmd/zz_gen_cmd_dnshelp.go

@@ -36,6 +36,7 @@ func allDNSCodes() string {
 		"dreamhost",
 		"duckdns",
 		"dyn",
+		"dynu",
 		"easydns",
 		"exec",
 		"exoscale",
@@ -563,6 +564,26 @@ func displayDNSHelp(name string) error {
 		ew.writeln()
 		ew.writeln(`More information: https://go-acme.github.io/lego/dns/dyn`)
 
+	case "dynu":
+		// generated from: providers/dns/dynu/dynu.toml
+		ew.writeln(`Configuration for Dynu.`)
+		ew.writeln(`Code:	'dynu'`)
+		ew.writeln(`Since:	'v3.5.0'`)
+		ew.writeln()
+
+		ew.writeln(`Credentials:`)
+		ew.writeln(`	- "DYNU_API_KEY":	API key`)
+		ew.writeln()
+
+		ew.writeln(`Additional Configuration:`)
+		ew.writeln(`	- "DYNU_HTTP_TIMEOUT":	API request timeout`)
+		ew.writeln(`	- "DYNU_POLLING_INTERVAL":	Time between DNS propagation check`)
+		ew.writeln(`	- "DYNU_PROPAGATION_TIMEOUT":	Maximum waiting time for DNS propagation`)
+		ew.writeln(`	- "DYNU_TTL":	The TTL of the TXT record used for the DNS challenge`)
+
+		ew.writeln()
+		ew.writeln(`More information: https://go-acme.github.io/lego/dns/dynu`)
+
 	case "easydns":
 		// generated from: providers/dns/easydns/easydns.toml
 		ew.writeln(`Configuration for EasyDNS.`)

docs/content/dns/zz_gen_dynu.md

@@ -0,0 +1,62 @@
+---
+title: "Dynu"
+date: 2019-03-03T16:39:46+01:00
+draft: false
+slug: dynu
+---
+
+<!-- THIS DOCUMENTATION IS AUTO-GENERATED. PLEASE DO NOT EDIT. -->
+<!-- providers/dns/dynu/dynu.toml -->
+<!-- THIS DOCUMENTATION IS AUTO-GENERATED. PLEASE DO NOT EDIT. -->
+
+Since: v3.5.0
+
+Configuration for [Dynu](https://www.dynu.com/).
+
+
+<!--more-->
+
+- Code: `dynu`
+
+Here is an example bash command using the Dynu provider:
+
+```bash
+DYNU_API_KEY=1234567890abcdefghijklmnopqrstuvwxyz \
+lego --dns dynu --domains my.domain.com --email my@email.com run
+```
+
+
+
+
+## Credentials
+
+| Environment Variable Name | Description |
+|-----------------------|-------------|
+| `DYNU_API_KEY` | API key |
+
+The environment variable names can be suffixed by `_FILE` to reference a file instead of a value.
+More information [here](/lego/dns/#configuration-and-credentials).
+
+
+## Additional Configuration
+
+| Environment Variable Name | Description |
+|--------------------------------|-------------|
+| `DYNU_HTTP_TIMEOUT` | API request timeout |
+| `DYNU_POLLING_INTERVAL` | Time between DNS propagation check |
+| `DYNU_PROPAGATION_TIMEOUT` | Maximum waiting time for DNS propagation |
+| `DYNU_TTL` | The TTL of the TXT record used for the DNS challenge |
+
+The environment variable names can be suffixed by `_FILE` to reference a file instead of a value.
+More information [here](/lego/dns/#configuration-and-credentials).
+
+
+
+
+## More information
+
+- [API documentation](https://www.dynu.com/en-US/Support/API)
+
+<!-- THIS DOCUMENTATION IS AUTO-GENERATED. PLEASE DO NOT EDIT. -->
+<!-- providers/dns/dynu/dynu.toml -->
+<!-- THIS DOCUMENTATION IS AUTO-GENERATED. PLEASE DO NOT EDIT. -->

providers/dns/dns_providers.go

@@ -27,6 +27,7 @@ import (
 	"github.com/go-acme/lego/v3/providers/dns/dreamhost"
 	"github.com/go-acme/lego/v3/providers/dns/duckdns"
 	"github.com/go-acme/lego/v3/providers/dns/dyn"
+	"github.com/go-acme/lego/v3/providers/dns/dynu"
 	"github.com/go-acme/lego/v3/providers/dns/easydns"
 	"github.com/go-acme/lego/v3/providers/dns/exec"
 	"github.com/go-acme/lego/v3/providers/dns/exoscale"
@@ -120,6 +121,8 @@ func NewDNSChallengeProviderByName(name string) (challenge.Provider, error) {
 		return duckdns.NewDNSProvider()
 	case "dyn":
 		return dyn.NewDNSProvider()
+	case "dynu":
+		return dynu.NewDNSProvider()
 	case "fastdns":
 		return fastdns.NewDNSProvider()
 	case "easydns":

providers/dns/dynu/dynu.go

@@ -0,0 +1,161 @@
+// Package dynu implements a DNS provider for solving the DNS-01 challenge using Dynu DNS.
+package dynu
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/go-acme/lego/v3/challenge/dns01"
+	"github.com/go-acme/lego/v3/platform/config/env"
+	"github.com/go-acme/lego/v3/providers/dns/dynu/internal"
+	"github.com/miekg/dns"
+)
+
+// Environment variables names.
+const (
+	envNamespace = "DYNU_"
+
+	EnvAPIKey = envNamespace + "API_KEY"
+
+	EnvTTL                = envNamespace + "TTL"
+	EnvPropagationTimeout = envNamespace + "PROPAGATION_TIMEOUT"
+	EnvPollingInterval    = envNamespace + "POLLING_INTERVAL"
+	EnvHTTPTimeout        = envNamespace + "HTTP_TIMEOUT"
+)
+
+// Config is used to configure the creation of the DNSProvider
+type Config struct {
+	APIKey string
+
+	PropagationTimeout time.Duration
+	PollingInterval    time.Duration
+	TTL                int
+	HTTPClient         *http.Client
+}
+
+// NewDefaultConfig returns a default configuration for the DNSProvider
+func NewDefaultConfig() *Config {
+	return &Config{
+		TTL:                env.GetOrDefaultInt(EnvTTL, 300),
+		PropagationTimeout: env.GetOrDefaultSecond(EnvPropagationTimeout, 3*time.Minute),
+		PollingInterval:    env.GetOrDefaultSecond(EnvPollingInterval, 10*time.Second),
+		HTTPClient: &http.Client{
+			Timeout: env.GetOrDefaultSecond(EnvHTTPTimeout, 30*time.Second),
+		},
+	}
+}
+
+// DNSProvider is an implementation of the challenge.Provider interface.
+type DNSProvider struct {
+	config *Config
+	client *internal.Client
+}
+
+// NewDNSProvider returns a DNSProvider instance configured for Dynu.
+// Credentials must be passed in the environment variables.
+func NewDNSProvider() (*DNSProvider, error) {
+	values, err := env.Get(EnvAPIKey)
+	if err != nil {
+		return nil, fmt.Errorf("dynu: %w", err)
+	}
+
+	config := NewDefaultConfig()
+	config.APIKey = values[EnvAPIKey]
+
+	return NewDNSProviderConfig(config)
+}
+
+// NewDNSProviderConfig return a DNSProvider instance configured for Dynu.
+func NewDNSProviderConfig(config *Config) (*DNSProvider, error) {
+	if config == nil {
+		return nil, errors.New("dynu: the configuration of the DNS provider is nil")
+	}
+
+	if config.APIKey == "" {
+		return nil, errors.New("dynu: incomplete credentials, missing API key")
+	}
+
+	tr, err := internal.NewTokenTransport(config.APIKey)
+	if err != nil {
+		return nil, fmt.Errorf("dynu: %w", err)
+	}
+
+	client := internal.NewClient()
+	client.HTTPClient = tr.Wrap(config.HTTPClient)
+
+	return &DNSProvider{config: config, client: client}, 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 using the specified parameters
+func (d *DNSProvider) Present(domain, token, keyAuth string) error {
+	fqdn, value := dns01.GetRecord(domain, keyAuth)
+
+	rootDomain, err := d.client.GetRootDomain(domain)
+	if err != nil {
+		return fmt.Errorf("dynu: could not find root domain for %s: %w", domain, err)
+	}
+
+	records, err := d.client.GetRecords(dns01.UnFqdn(fqdn), "TXT")
+	if err != nil {
+		return fmt.Errorf("dynu: failed to get records for %s: %w", domain, err)
+	}
+
+	for _, record := range records {
+		// the record already exist
+		if record.Hostname == dns01.UnFqdn(fqdn) && record.TextData == value {
+			return nil
+		}
+	}
+
+	record := internal.DNSRecord{
+		Type:       "TXT",
+		DomainName: rootDomain.DomainName,
+		Hostname:   dns01.UnFqdn(fqdn),
+		NodeName:   dns01.UnFqdn(strings.TrimSuffix(fqdn, dns.Fqdn(domain))),
+		TextData:   value,
+		State:      true,
+		TTL:        300,
+	}
+
+	err = d.client.AddNewRecord(rootDomain.ID, record)
+	if err != nil {
+		return fmt.Errorf("dynu: failed to add record to %s: %w", domain, err)
+	}
+
+	return nil
+}
+
+// CleanUp removes the TXT record matching the specified parameters
+func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error {
+	fqdn, value := dns01.GetRecord(domain, keyAuth)
+
+	rootDomain, err := d.client.GetRootDomain(domain)
+	if err != nil {
+		return fmt.Errorf("dynu: could not find root domain for %s: %w", domain, err)
+	}
+
+	records, err := d.client.GetRecords(dns01.UnFqdn(fqdn), "TXT")
+	if err != nil {
+		return fmt.Errorf("dynu: failed to get records for %s: %w", domain, err)
+	}
+
+	for _, record := range records {
+		if record.Hostname == dns01.UnFqdn(fqdn) && record.TextData == value {
+			err = d.client.DeleteRecord(rootDomain.ID, record.ID)
+			if err != nil {
+				return fmt.Errorf("dynu: failed to remove TXT record for %s: %w", domain, err)
+			}
+		}
+	}
+
+	return nil
+}

providers/dns/dynu/dynu.toml

@@ -0,0 +1,22 @@
+Name = "Dynu"
+Description = ''''''
+URL = "https://www.dynu.com/"
+Code = "dynu"
+Since = "v3.5.0"
+
+Example = '''
+DYNU_API_KEY=1234567890abcdefghijklmnopqrstuvwxyz \
+lego --dns dynu --domains my.domain.com --email my@email.com run
+'''
+
+[Configuration]
+  [Configuration.Credentials]
+    DYNU_API_KEY = "API key"
+  [Configuration.Additional]
+    DYNU_POLLING_INTERVAL = "Time between DNS propagation check"
+    DYNU_PROPAGATION_TIMEOUT = "Maximum waiting time for DNS propagation"
+    DYNU_TTL = "The TTL of the TXT record used for the DNS challenge"
+    DYNU_HTTP_TIMEOUT = "API request timeout"
+
+[Links]
+  API = "https://www.dynu.com/en-US/Support/API"

providers/dns/dynu/dynu_test.go

@@ -0,0 +1,119 @@
+package dynu
+
+import (
+	"testing"
+	"time"
+
+	"github.com/go-acme/lego/v3/platform/tester"
+	"github.com/stretchr/testify/require"
+)
+
+const envDomain = envNamespace + "_DOMAIN"
+
+var envTest = tester.NewEnvTest(
+	EnvAPIKey).
+	WithDomain(envDomain)
+
+func TestNewDNSProvider(t *testing.T) {
+	testCases := []struct {
+		desc     string
+		envVars  map[string]string
+		expected string
+	}{
+		{
+			desc: "success",
+			envVars: map[string]string{
+				EnvAPIKey: "123",
+			},
+		},
+		{
+			desc: "missing api key",
+			envVars: map[string]string{
+				EnvAPIKey: "",
+			},
+			expected: "dynu: some credentials information are missing: DYNU_API_KEY",
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			defer envTest.RestoreEnv()
+			envTest.ClearEnv()
+
+			envTest.Apply(test.envVars)
+
+			p, err := NewDNSProvider()
+
+			if len(test.expected) == 0 {
+				require.NoError(t, err)
+				require.NotNil(t, p)
+				require.NotNil(t, p.config)
+			} else {
+				require.EqualError(t, err, test.expected)
+			}
+		})
+	}
+}
+
+func TestNewDNSProviderConfig(t *testing.T) {
+	testCases := []struct {
+		desc     string
+		expected string
+		apiKey   string
+	}{
+		{
+			desc:   "success",
+			apiKey: "api_key",
+		},
+		{
+			desc:     "missing api key",
+			apiKey:   "",
+			expected: "dynu: incomplete credentials, missing API key",
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			config := NewDefaultConfig()
+			config.APIKey = test.apiKey
+
+			p, err := NewDNSProviderConfig(config)
+
+			if len(test.expected) == 0 {
+				require.NoError(t, err)
+				require.NotNil(t, p)
+				require.NotNil(t, p.config)
+			} else {
+				require.EqualError(t, err, test.expected)
+			}
+		})
+	}
+}
+
+func TestLivePresent(t *testing.T) {
+	if !envTest.IsLiveTest() {
+		t.Skip("skipping live test")
+	}
+
+	envTest.RestoreEnv()
+	provider, err := NewDNSProvider()
+	require.NoError(t, err)
+
+	err = provider.Present(envTest.GetDomain(), "", "123d==")
+	require.NoError(t, err)
+}
+
+func TestLiveCleanUp(t *testing.T) {
+	if !envTest.IsLiveTest() {
+		t.Skip("skipping live test")
+	}
+
+	envTest.RestoreEnv()
+	provider, err := NewDNSProvider()
+	require.NoError(t, err)
+
+	time.Sleep(1 * time.Second)
+
+	err = provider.CleanUp(envTest.GetDomain(), "", "123d==")
+	require.NoError(t, err)
+}

providers/dns/dynu/internal/auth.go

@@ -0,0 +1,64 @@
+package internal
+
+import (
+	"errors"
+	"net/http"
+)
+
+const apiKeyHeader = "Api-Key"
+
+// TokenTransport HTTP transport for API authentication.
+type TokenTransport struct {
+	apiKey string
+
+	// Transport is the underlying HTTP transport to use when making requests.
+	// It will default to http.DefaultTransport if nil.
+	Transport http.RoundTripper
+}
+
+// NewTokenTransport Creates a HTTP transport for API authentication.
+func NewTokenTransport(apiKey string) (*TokenTransport, error) {
+	if apiKey == "" {
+		return nil, errors.New("credentials missing: API key")
+	}
+
+	return &TokenTransport{apiKey: apiKey}, nil
+}
+
+// RoundTrip executes a single HTTP transaction
+func (t *TokenTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	enrichedReq := &http.Request{}
+	*enrichedReq = *req
+
+	enrichedReq.Header = make(http.Header, len(req.Header))
+	for k, s := range req.Header {
+		enrichedReq.Header[k] = append([]string(nil), s...)
+	}
+
+	if t.apiKey != "" {
+		enrichedReq.Header.Add(apiKeyHeader, t.apiKey)
+	}
+
+	return t.transport().RoundTrip(enrichedReq)
+}
+
+func (t *TokenTransport) transport() http.RoundTripper {
+	if t.Transport != nil {
+		return t.Transport
+	}
+	return http.DefaultTransport
+}
+
+// Client Creates a new HTTP client
+func (t *TokenTransport) Client() *http.Client {
+	return &http.Client{Transport: t}
+}
+
+// Wrap Wrap a HTTP client Transport with the TokenTransport
+func (t *TokenTransport) Wrap(client *http.Client) *http.Client {
+	backup := client.Transport
+	t.Transport = backup
+	client.Transport = t
+
+	return client
+}

providers/dns/dynu/internal/auth_test.go

@@ -0,0 +1,40 @@
+package internal
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewTokenTransport_success(t *testing.T) {
+	apiKey := "api"
+
+	transport, err := NewTokenTransport(apiKey)
+	require.NoError(t, err)
+	assert.NotNil(t, transport)
+}
+
+func TestNewTokenTransport_missing_credentials(t *testing.T) {
+	apiKey := ""
+
+	transport, err := NewTokenTransport(apiKey)
+	require.Error(t, err)
+	assert.Nil(t, transport)
+}
+
+func TestTokenTransport_RoundTrip(t *testing.T) {
+	apiKey := "api"
+
+	transport, err := NewTokenTransport(apiKey)
+	require.NoError(t, err)
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com", nil)
+
+	resp, err := transport.RoundTrip(req)
+	require.NoError(t, err)
+
+	assert.Equal(t, "api", resp.Request.Header.Get(apiKeyHeader))
+}

providers/dns/dynu/internal/client.go

@@ -0,0 +1,186 @@
+package internal
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path"
+	"strconv"
+	"time"
+
+	"github.com/cenkalti/backoff/v4"
+	"github.com/go-acme/lego/v3/log"
+)
+
+const defaultBaseURL = "https://api.dynu.com/v2"
+
+type Client struct {
+	HTTPClient *http.Client
+	BaseURL    string
+}
+
+func NewClient() *Client {
+	return &Client{
+		HTTPClient: http.DefaultClient,
+		BaseURL:    defaultBaseURL,
+	}
+}
+
+// GetRecords Get DNS records based on a hostname and resource record type.
+func (c Client) GetRecords(hostname string, recordType string) ([]DNSRecord, error) {
+	endpoint, err := c.createEndpoint("dns", "record", hostname)
+	if err != nil {
+		return nil, err
+	}
+
+	query := endpoint.Query()
+	query.Set("recordType", recordType)
+	endpoint.RawQuery = query.Encode()
+
+	apiResp := RecordsResponse{}
+	err = c.doRetry(http.MethodGet, endpoint.String(), nil, &apiResp)
+	if err != nil {
+		return nil, err
+	}
+
+	if apiResp.StatusCode/100 != 2 {
+		return nil, fmt.Errorf("API error: %w", apiResp.APIException)
+	}
+
+	return apiResp.DNSRecords, nil
+}
+
+// AddNewRecord Add a new DNS record for DNS service.
+func (c Client) AddNewRecord(domainID int64, record DNSRecord) error {
+	endpoint, err := c.createEndpoint("dns", strconv.FormatInt(domainID, 10), "record")
+	if err != nil {
+		return err
+	}
+
+	reqBody, err := json.Marshal(record)
+	if err != nil {
+		return err
+	}
+
+	apiResp := RecordResponse{}
+	err = c.doRetry(http.MethodPost, endpoint.String(), reqBody, &apiResp)
+	if err != nil {
+		return err
+	}
+
+	if apiResp.StatusCode/100 != 2 {
+		return fmt.Errorf("API error: %w", apiResp.APIException)
+	}
+
+	return nil
+}
+
+// DeleteRecord Remove a DNS record from DNS service.
+func (c Client) DeleteRecord(domainID int64, recordID int64) error {
+	endpoint, err := c.createEndpoint("dns", strconv.FormatInt(domainID, 10), "record", strconv.FormatInt(recordID, 10))
+	if err != nil {
+		return err
+	}
+
+	apiResp := APIException{}
+	err = c.doRetry(http.MethodDelete, endpoint.String(), nil, &apiResp)
+	if err != nil {
+		return err
+	}
+
+	if apiResp.StatusCode/100 != 2 {
+		return fmt.Errorf("API error: %w", apiResp)
+	}
+
+	return nil
+}
+
+// GetRootDomain Get the root domain name based on a hostname.
+func (c Client) GetRootDomain(hostname string) (*DNSHostname, error) {
+	endpoint, err := c.createEndpoint("dns", "getroot", hostname)
+	if err != nil {
+		return nil, err
+	}
+
+	apiResp := DNSHostname{}
+	err = c.doRetry(http.MethodGet, endpoint.String(), nil, &apiResp)
+	if err != nil {
+		return nil, err
+	}
+
+	if apiResp.StatusCode/100 != 2 {
+		return nil, fmt.Errorf("API error: %w", apiResp.APIException)
+	}
+
+	return &apiResp, nil
+}
+
+// doRetry the API is really unstable so we need to retry on EOF.
+func (c Client) doRetry(method, url string, body []byte, data interface{}) error {
+	var resp *http.Response
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	operation := func() error {
+		var reqBody io.Reader
+		if len(body) > 0 {
+			reqBody = bytes.NewReader(body)
+		}
+
+		req, err := http.NewRequest(method, url, reqBody)
+		if err != nil {
+			return err
+		}
+
+		req.Header.Add("Content-Type", "application/json")
+		req.Header.Add("Accept", "application/json")
+
+		resp, err = c.HTTPClient.Do(req)
+		if errors.Is(err, io.EOF) {
+			return err
+		}
+
+		if err != nil {
+			cancel()
+			return fmt.Errorf("client error: %w", err)
+		}
+
+		return nil
+	}
+
+	notify := func(err error, duration time.Duration) {
+		log.Printf("client retries because of %v", err)
+	}
+
+	bo := backoff.NewExponentialBackOff()
+	bo.InitialInterval = 1 * time.Second
+
+	err := backoff.RetryNotify(operation, backoff.WithContext(bo, ctx), notify)
+	if err != nil {
+		return err
+	}
+
+	defer func() { _ = resp.Body.Close() }()
+
+	all, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("failed to read response body: %w", err)
+	}
+
+	return json.Unmarshal(all, data)
+}
+
+func (c Client) createEndpoint(fragments ...string) (*url.URL, error) {
+	baseURL, err := url.Parse(c.BaseURL)
+	if err != nil {
+		return nil, err
+	}
+
+	return baseURL.Parse(path.Join(baseURL.Path, path.Join(fragments...)))
+}

providers/dns/dynu/internal/client_test.go

@@ -0,0 +1,302 @@
+package internal
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func setupTest(method string, pattern string, status int, file string) *Client {
+	mux := http.NewServeMux()
+	server := httptest.NewServer(mux)
+
+	mux.HandleFunc(pattern, func(rw http.ResponseWriter, req *http.Request) {
+		if req.Method != method {
+			http.Error(rw, fmt.Sprintf("unsupported method %s", req.Method), http.StatusBadRequest)
+			return
+		}
+
+		open, err := os.Open(file)
+		if err != nil {
+			http.Error(rw, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		defer func() { _ = open.Close() }()
+
+		rw.WriteHeader(status)
+		_, err = io.Copy(rw, open)
+		if err != nil {
+			http.Error(rw, err.Error(), http.StatusInternalServerError)
+			return
+		}
+	})
+
+	client := NewClient()
+	client.BaseURL = server.URL
+
+	return client
+}
+
+func TestGetRootDomain(t *testing.T) {
+	type expected struct {
+		domain *DNSHostname
+		error  string
+	}
+
+	testCases := []struct {
+		desc     string
+		pattern  string
+		status   int
+		file     string
+		expected expected
+	}{
+		{
+			desc:    "success",
+			pattern: "/dns/getroot/test.lego.freeddns.org",
+			status:  http.StatusOK,
+			file:    "./fixtures/get_root_domain.json",
+			expected: expected{
+				domain: &DNSHostname{
+					APIException: &APIException{
+						StatusCode: 200,
+					},
+					ID:         9007481,
+					DomainName: "lego.freeddns.org",
+					Hostname:   "test.lego.freeddns.org",
+					Node:       "test",
+				},
+			},
+		},
+		{
+			desc:    "invalid",
+			pattern: "/dns/getroot/test.lego.freeddns.org",
+			status:  http.StatusNotImplemented,
+			file:    "./fixtures/get_root_domain_invalid.json",
+			expected: expected{
+				error: "API error: 501: Argument Exception: Invalid.",
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			client := setupTest(http.MethodGet, test.pattern, test.status, test.file)
+
+			domain, err := client.GetRootDomain("test.lego.freeddns.org")
+
+			if test.expected.error != "" {
+				assert.EqualError(t, err, test.expected.error)
+				return
+			}
+
+			require.NoError(t, err)
+
+			assert.NotNil(t, domain)
+			assert.Equal(t, test.expected.domain, domain)
+		})
+	}
+}
+
+func TestGetRecords(t *testing.T) {
+	type expected struct {
+		records []DNSRecord
+		error   string
+	}
+
+	testCases := []struct {
+		desc     string
+		pattern  string
+		status   int
+		file     string
+		expected expected
+	}{
+		{
+			desc:    "success",
+			pattern: "/dns/record/_acme-challenge.lego.freeddns.org",
+			status:  http.StatusOK,
+			file:    "./fixtures/get_records.json",
+			expected: expected{
+				records: []DNSRecord{{
+					ID:         6041417,
+					Type:       "TXT",
+					DomainID:   9007481,
+					DomainName: "lego.freeddns.org",
+					NodeName:   "_acme-challenge",
+					Hostname:   "_acme-challenge.lego.freeddns.org",
+					State:      true,
+					Content:    `_acme-challenge.lego.freeddns.org. 300 IN TXT "txt_txt_txt_txt_txt_txt_txt"`,
+					TextData:   "txt_txt_txt_txt_txt_txt_txt",
+					TTL:        300,
+				},
+					{
+						ID:         6041422,
+						Type:       "TXT",
+						DomainID:   9007481,
+						DomainName: "lego.freeddns.org",
+						NodeName:   "_acme-challenge",
+						Hostname:   "_acme-challenge.lego.freeddns.org",
+						State:      true,
+						Content:    `_acme-challenge.lego.freeddns.org. 300 IN TXT "txt_txt_txt_txt_txt_txt_txt_2"`,
+						TextData:   "txt_txt_txt_txt_txt_txt_txt_2",
+						TTL:        300,
+					},
+				},
+			},
+		},
+		{
+			desc:    "empty",
+			pattern: "/dns/record/_acme-challenge.lego.freeddns.org",
+			status:  http.StatusOK,
+			file:    "./fixtures/get_records_empty.json",
+			expected: expected{
+				records: []DNSRecord{},
+			},
+		},
+		{
+			desc:    "invalid",
+			pattern: "/dns/record/_acme-challenge.lego.freeddns.org",
+			status:  http.StatusNotImplemented,
+			file:    "./fixtures/get_records_invalid.json",
+			expected: expected{
+				error: "API error: 501: Argument Exception: Invalid.",
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			client := setupTest(http.MethodGet, test.pattern, test.status, test.file)
+
+			records, err := client.GetRecords("_acme-challenge.lego.freeddns.org", "TXT")
+
+			if test.expected.error != "" {
+				assert.EqualError(t, err, test.expected.error)
+				return
+			}
+
+			require.NoError(t, err)
+
+			assert.NotNil(t, records)
+			assert.Equal(t, test.expected.records, records)
+		})
+	}
+}
+
+func TestAddNewRecord(t *testing.T) {
+	type expected struct {
+		error string
+	}
+
+	testCases := []struct {
+		desc     string
+		pattern  string
+		status   int
+		file     string
+		expected expected
+	}{
+		{
+			desc:    "success",
+			pattern: "/dns/9007481/record",
+			status:  http.StatusOK,
+			file:    "./fixtures/add_new_record.json",
+		},
+		{
+			desc:    "invalid",
+			pattern: "/dns/9007481/record",
+			status:  http.StatusNotImplemented,
+			file:    "./fixtures/add_new_record_invalid.json",
+			expected: expected{
+				error: "API error: 501: Argument Exception: Invalid.",
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			client := setupTest(http.MethodPost, test.pattern, test.status, test.file)
+
+			record := DNSRecord{
+				Type:       "TXT",
+				DomainName: "lego.freeddns.org",
+				Hostname:   "_acme-challenge.lego.freeddns.org",
+				NodeName:   "_acme-challenge",
+				TextData:   "txt_txt_txt_txt_txt_txt_txt_2",
+				State:      true,
+				TTL:        300,
+			}
+
+			err := client.AddNewRecord(9007481, record)
+
+			if test.expected.error != "" {
+				assert.EqualError(t, err, test.expected.error)
+				return
+			}
+
+			require.NoError(t, err)
+		})
+	}
+}
+
+func TestDeleteRecord(t *testing.T) {
+	type expected struct {
+		error string
+	}
+
+	testCases := []struct {
+		desc     string
+		pattern  string
+		status   int
+		file     string
+		expected expected
+	}{
+		{
+			desc:    "success",
+			pattern: "/",
+			status:  http.StatusOK,
+			file:    "./fixtures/delete_record.json",
+		},
+		{
+			desc:    "invalid",
+			pattern: "/",
+			status:  http.StatusNotImplemented,
+			file:    "./fixtures/delete_record_invalid.json",
+			expected: expected{
+				error: "API error: 501: Argument Exception: Invalid.",
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			client := setupTest(http.MethodDelete, test.pattern, test.status, test.file)
+
+			err := client.DeleteRecord(9007481, 6041418)
+
+			if test.expected.error != "" {
+				assert.EqualError(t, err, test.expected.error)
+				return
+			}
+
+			require.NoError(t, err)
+		})
+	}
+}

providers/dns/dynu/internal/fixtures/add_new_record.json

@@ -0,0 +1,14 @@
+{
+  "statusCode": 200,
+  "id": 6041417,
+  "domainId": 9007481,
+  "domainName": "lego.freeddns.org",
+  "nodeName": "_acme-challenge",
+  "hostname": "_acme-challenge.lego.freeddns.org",
+  "recordType": "TXT",
+  "ttl": 300,
+  "state": true,
+  "content": "_acme-challenge.lego.freeddns.org. 300 IN TXT \"txt_txt_txt_txt_txt_txt_txt\"",
+  "updatedOn": "2020-03-10T04:00:36.923",
+  "textData": "txt_txt_txt_txt_txt_txt_txt"
+}

providers/dns/dynu/internal/fixtures/add_new_record_invalid.json

@@ -0,0 +1,5 @@
+{
+  "statusCode": 501,
+  "type": "Argument Exception",
+  "message": "Invalid."
+}

providers/dns/dynu/internal/fixtures/delete_record.json

@@ -0,0 +1,3 @@
+{
+  "statusCode": 200
+}

providers/dns/dynu/internal/fixtures/delete_record_invalid.json

@@ -0,0 +1,5 @@
+{
+  "statusCode": 501,
+  "type": "Argument Exception",
+  "message": "Invalid."
+}

providers/dns/dynu/internal/fixtures/get_records.json

@@ -0,0 +1,31 @@
+{
+  "statusCode": 200,
+  "dnsRecords": [
+    {
+      "id": 6041417,
+      "domainId": 9007481,
+      "domainName": "lego.freeddns.org",
+      "nodeName": "_acme-challenge",
+      "hostname": "_acme-challenge.lego.freeddns.org",
+      "recordType": "TXT",
+      "ttl": 300,
+      "state": true,
+      "content": "_acme-challenge.lego.freeddns.org. 300 IN TXT \"txt_txt_txt_txt_txt_txt_txt\"",
+      "updatedOn": "2020-03-10T04:00:36.923",
+      "textData": "txt_txt_txt_txt_txt_txt_txt"
+    },
+    {
+      "id": 6041422,
+      "domainId": 9007481,
+      "domainName": "lego.freeddns.org",
+      "nodeName": "_acme-challenge",
+      "hostname": "_acme-challenge.lego.freeddns.org",
+      "recordType": "TXT",
+      "ttl": 300,
+      "state": true,
+      "content": "_acme-challenge.lego.freeddns.org. 300 IN TXT \"txt_txt_txt_txt_txt_txt_txt_2\"",
+      "updatedOn": "2020-03-10T04:03:17.563",
+      "textData": "txt_txt_txt_txt_txt_txt_txt_2"
+    }
+  ]
+}

providers/dns/dynu/internal/fixtures/get_records_empty.json

@@ -0,0 +1,4 @@
+{
+  "statusCode": 200,
+  "dnsRecords": []
+}

providers/dns/dynu/internal/fixtures/get_records_invalid.json

@@ -0,0 +1,5 @@
+{
+  "statusCode": 501,
+  "type": "Argument Exception",
+  "message": "Invalid."
+}

providers/dns/dynu/internal/fixtures/get_root_domain.json

@@ -0,0 +1,7 @@
+{
+  "statusCode": 200,
+  "id": 9007481,
+  "domainName": "lego.freeddns.org",
+  "hostname": "test.lego.freeddns.org",
+  "node": "test"
+}

providers/dns/dynu/internal/fixtures/get_root_domain_invalid.json

@@ -0,0 +1,5 @@
+{
+  "statusCode": 501,
+  "type": "Argument Exception",
+  "message": "Invalid."
+}

providers/dns/dynu/internal/model.go

@@ -0,0 +1,58 @@
+package internal
+
+import "fmt"
+
+// APIException defines model for apiException.
+type APIException struct {
+	Message    string `json:"message,omitempty"`
+	StatusCode int32  `json:"statusCode,omitempty"`
+	Type       string `json:"type,omitempty"`
+}
+
+func (a APIException) Error() string {
+	return fmt.Sprintf("%d: %s: %s", a.StatusCode, a.Type, a.Message)
+}
+
+// APIResponse defines model for apiResponse.
+type APIResponse struct {
+	Exception  *APIException `json:"exception,omitempty"`
+	StatusCode int32         `json:"statusCode,omitempty"`
+}
+
+// DNSRecord defines model for dnsRecords.
+type DNSRecord struct {
+	ID         int64  `json:"id,omitempty"`
+	Type       string `json:"recordType,omitempty"`
+	DomainID   int64  `json:"domainId,omitempty"`
+	DomainName string `json:"domainName,omitempty"`
+	NodeName   string `json:"nodeName,omitempty"`
+	Hostname   string `json:"hostname,omitempty"`
+	State      bool   `json:"state,omitempty"`
+	Content    string `json:"content,omitempty"`
+	TextData   string `json:"textData,omitempty"`
+	TTL        int    `json:"ttl,omitempty"`
+}
+
+// DNSHostname defines model for DNS.hostname.
+type DNSHostname struct {
+	*APIException
+
+	ID         int64  `json:"id,omitempty"`
+	DomainName string `json:"domainName,omitempty"`
+	Hostname   string `json:"hostname,omitempty"`
+	Node       string `json:"node,omitempty"`
+}
+
+// RecordsResponse defines model for recordsResponse.
+type RecordsResponse struct {
+	*APIException
+
+	DNSRecords []DNSRecord `json:"dnsRecords,omitempty"`
+}
+
+// RecordResponse defines model for recordResponse.
+type RecordResponse struct {
+	*APIException
+
+	DNSRecord
+}