main.go

@@ -8,6 +8,8 @@ import (
 	ionos "realdnydns/pkg/dnsProvider/ionos"
 	"realdnydns/pkg/externalIpProvider"
 	plainExternalIpProvider "realdnydns/pkg/externalIpProvider/plain"
+	"realdnydns/pkg/notificationProvider"
+	notificationProviderConsole "realdnydns/pkg/notificationProvider/console"
 	"time"
 
 	"github.com/go-co-op/gocron"
@@ -50,7 +52,14 @@ func main() {
 		panic(fmt.Errorf("unknown DNS provider: %s", configClient.DNSProvider.Type))
 	}
 
-	changeDetector := changeDetector.New(externalIpProvider, dnsProvider, configClient.Domains)
+	var notificationProvider notificationProvider.NotificationProvider
+	switch configClient.NotificationProvider.Type {
+	default:
+		// Use default console notification provider
+		notificationProvider = notificationProviderConsole.New()
+	}
+
+	changeDetector := changeDetector.New(externalIpProvider, dnsProvider, notificationProvider, configClient.Domains)
 
 	s := gocron.NewScheduler(time.UTC)
 	s.SingletonMode()

pkg/changeDetector/changeDetector.go

@@ -1,26 +1,31 @@
 package changeDetector
 
 import (
+	"fmt"
 	"realdnydns/pkg/config"
 	"realdnydns/pkg/dnsProvider"
 	"realdnydns/pkg/externalIpProvider"
+	"realdnydns/pkg/notificationProvider"
 )
 
 type ChangeDetector struct {
-	externalIpProvider externalIpProvider.ExternalIpProvider
+	externalIpProvider   externalIpProvider.ExternalIpProvider
-	dnsProvider        dnsProvider.DNSProvider
+	dnsProvider          dnsProvider.DNSProvider
-	domains            []config.DomainConfig
+	notificationProvider notificationProvider.NotificationProvider
+	domains              []config.DomainConfig
 }
 
 func New(
 	externalIpProvider externalIpProvider.ExternalIpProvider,
 	dnsProvider dnsProvider.DNSProvider,
+	notificationProvider notificationProvider.NotificationProvider,
 	domains []config.DomainConfig,
 ) ChangeDetector {
 	return ChangeDetector{
-		externalIpProvider: externalIpProvider,
+		externalIpProvider:   externalIpProvider,
-		dnsProvider:        dnsProvider,
+		dnsProvider:          dnsProvider,
-		domains:            domains,
+		notificationProvider: notificationProvider,
+		domains:              domains,
 	}
 }
 
@@ -40,6 +45,14 @@ func (c *ChangeDetector) DetectAndApplyChanges() (int, error) {
 			}
 
 			if currentRecord.IP != externalIp.String() {
+				err = c.notificationProvider.SendNotification(
+					fmt.Sprintf("Update %s.%s", subdomain, domain.TLD),
+					fmt.Sprintf("The IP of %s has changed from %s to %s", domain.TLD, currentRecord.IP, externalIp.String()),
+				)
+				if err != nil {
+					return numberUpdated, err
+				}
+
 				_, err = c.dnsProvider.UpdateRecord(domain.TLD, subdomain, externalIp, currentRecord.TTL, currentRecord.Prio, currentRecord.Disabled)
 				numberUpdated++
 				if err != nil {

pkg/changeDetector/changeDetector_test.go

@@ -43,6 +43,14 @@ func (m *MockDNSProviderImpl) UpdateRecord(tld string, subdomain string, ip net.
 	}, nil
 }
 
+type MockedNotificationProvider struct{}
+
+type MockedNotificationProviderImpl struct{}
+
+func (m *MockedNotificationProviderImpl) SendNotification(title string, message string) error {
+	return nil
+}
+
 func TestDetectAndApplyChanges(t *testing.T) {
 	t.Run("with changes", testDetectAndApplyChangesWithChanges())
 	t.Run("without changes", testDetectAndApplyChangesWithoutChanges())
@@ -55,15 +63,16 @@ func testDetectAndApplyChangesWithChanges() func(t *testing.T) {
 		}, &MockDNSProviderImpl{
 			GetRecordIpResponse:    "127.0.0.2",
 			UpdateRecordIpResponse: "127.0.0.1",
-		}, []config.DomainConfig{
+		}, &MockedNotificationProviderImpl{},
-			{
+			[]config.DomainConfig{
-				TLD: "example.com",
+				{
-				Subdomains: []string{
+					TLD: "example.com",
-					"test",
+					Subdomains: []string{
-					"@",
+						"test",
+						"@",
+					},
 				},
-			},
+			})
-		})
 
 		numberUpdated, err := changeDetector.DetectAndApplyChanges()
 		if err != nil {
@@ -83,15 +92,16 @@ func testDetectAndApplyChangesWithoutChanges() func(t *testing.T) {
 		}, &MockDNSProviderImpl{
 			GetRecordIpResponse:    "127.0.0.1",
 			UpdateRecordIpResponse: "127.0.0.1",
-		}, []config.DomainConfig{
+		}, &MockedNotificationProviderImpl{},
-			{
+			[]config.DomainConfig{
-				TLD: "example.com",
+				{
-				Subdomains: []string{
+					TLD: "example.com",
-					"test",
+					Subdomains: []string{
-					"@",
+						"test",
+						"@",
+					},
 				},
-			},
+			})
-		})
 
 		numberUpdated, err := changeDetector.DetectAndApplyChanges()
 		if err != nil {

pkg/config/config.go

@@ -12,10 +12,11 @@ type DomainConfig struct {
 }
 
 type Config struct {
-	ExternalIPProvider ExternalIpProviderConfig `yaml:"ip_provider"`
+	ExternalIPProvider   ExternalIpProviderConfig   `yaml:"ip_provider"`
-	DNSProvider        DNSProviderConfig        `yaml:"dns_provider"`
+	DNSProvider          DNSProviderConfig          `yaml:"dns_provider"`
-	Domains            []DomainConfig           `yaml:"domains"`
+	NotificationProvider NotificationProviderConfig `yaml:"notification_provider,omitempty"`
-	CheckInterval      string                   `yaml:"check_interval"`
+	Domains              []DomainConfig             `yaml:"domains"`
+	CheckInterval        string                     `yaml:"check_interval"`
 }
 
 type ExternalIpProviderConfig struct {
@@ -28,6 +29,11 @@ type DNSProviderConfig struct {
 	ProviderConfig yaml.Node `yaml:"config"`
 }
 
+type NotificationProviderConfig struct {
+	Type           string    `yaml:"type"`
+	ProviderConfig yaml.Node `yaml:"config"`
+}
+
 func (c *Config) Load(filePath string) error {
 	err := yaml.Unmarshal([]byte(filePath), c)
 	if err != nil {

pkg/config/config_test.go

@@ -49,6 +49,10 @@ dns_provider:
   config:
     api_key: exampleAPIKey
     base_url: https://example.com
+notification_provider:
+  type: gotify
+  config:
+    url: https://example.com
 domains:
   - tld: example.com
     subdomains:
@@ -56,7 +60,7 @@ domains:
       - www
 check_interval: 0 0 0/6 * * * *`)
 
-		want := c.DNSProvider.Type == "ionos" && c.ExternalIPProvider.Type == "plain"
+		want := c.DNSProvider.Type == "ionos" && c.ExternalIPProvider.Type == "plain" && c.NotificationProvider.Type == "gotify"
 
 		if !want || err != nil {
 			t.Fatalf("DnsProviderName couldn't be properly loaded or unmarshaled, Load() = %v, want %v", err, want)

pkg/notificationProvider/console/console.go

@@ -0,0 +1,16 @@
+package notificationProviderConsole
+
+import (
+	"fmt"
+)
+
+type NotificationProviderImplConsole struct{}
+
+func New() *NotificationProviderImplConsole {
+	return &NotificationProviderImplConsole{}
+}
+
+func (p *NotificationProviderImplConsole) SendNotification(title string, message string) error {
+	fmt.Printf("%s: %s\n", title, message)
+	return nil
+}

pkg/notificationProvider/notificationProvider.go

@@ -0,0 +1,5 @@
+package notificationProvider
+
+type NotificationProvider interface {
+	SendNotification(title string, message string) error
+}