Refactor

Initial Notifiers implementation

Makefile

@@ -0,0 +1,2 @@
+test:
+	go test --cover -covermode count -v ./...

README.md

@@ -1,9 +1,11 @@
+![Code and security checks](https://github.com/mkelcik/cloudflare-ddns-update/actions/workflows/quality-checks.yml/badge.svg)
+
 ## What is Cloudflare Dynamic DNS?
 DNS records are static, and it does not play well with dynamic IP addresses. Now, to solve that problem, you’ll need to set up dynamic DNS. Cloudflare provides an API that allows you to manage DNS records programmatically.
 
 To set up a Cloudflare dynamic DNS, you’ll need to run a process on a client inside your network that does two main actions: get your network’s current public IP address and automatically update the corresponding DNS record.
 
-This simple updater do the job.
+This simple updater do the job, and send notifications, if change happen.
 
 ## How to run
 ### Environment variables
@@ -15,7 +17,10 @@ Before run, you need configure this environment variables.
  - `CLOUDFLARE_ZONE` - (required) zone name with domain you want to check. See: [https://developers.cloudflare.com/fundamentals/get-started/concepts/accounts-and-zones/#zones](https://developers.cloudflare.com/fundamentals/get-started/concepts/accounts-and-zones/#zones)
  - `ON_CHANGE_COMMENT` - (optional) in the event that the ip address of the dns record changes, this comment will be added to the record
  - `CHECK_INTERVAL_SECONDS` - (optional) how often will the ip address of the records be checked (default: `300`)
- - `PUBLIC_IP_RESOLVER` - (optional) public ip address resolver. (default: `ifconfig.me`) Available: `ifconfig.me`, `v4.ident.me`
+ - `PUBLIC_IP_RESOLVER` - (optional) public ip address resolver. (default: `ifconfig.me`) Available: `ifconfig.me`, `v4.ident.me`, `1.1.1.1`
+ - `NOTIFIERS` - (optional) setting the notifier in case of an update of the dns record. Multiple entries are separated by commas. (default none). Example: `webhook@http://localhost/cloudflare-notification` 
+   - Available
+     - `webhook` - Call defined webhook. Example: `webhook@http://localhost/cloudflare-notification`
 
 ### Building from source
 
@@ -59,4 +64,4 @@ docker run -e CLOUDFLARE_DNS_TO_CHECK=my.testdomain.com,your.testdomain.com -e C
 
 ### Contributing 
 
-Feel free to contribute and pls report bugs. Thanks
+Feel free to contribute and pls report bugs. Thanks

internal/config.go

@@ -17,6 +17,7 @@ const (
 	envKeyCloudflareZone       = "CLOUDFLARE_ZONE"
 	envKeyOnChangeComment      = "ON_CHANGE_COMMENT"
 	envKeyCheckIntervalSeconds = "CHECK_INTERVAL_SECONDS"
+	envKeyNotifiers            = "NOTIFIERS"
 )
 
 type Config struct {
@@ -25,6 +26,7 @@ type Config struct {
 	ApiToken            string
 	CloudflareZone      string
 	OnChangeComment     string
+	Notifiers           []string
 	CheckInterval       time.Duration
 }
 
@@ -52,11 +54,12 @@ func NewConfig() Config {
 	}
 
 	return Config{
-		DnsRecordsToCheck:   parseDNSToCheck(os.Getenv(envKeyDnsToCheck)),
+		DnsRecordsToCheck:   parseCommaDelimited(os.Getenv(envKeyDnsToCheck)),
 		PublicIpResolverTag: os.Getenv(envKeyPublicIpResolverTag),
 		ApiToken:            os.Getenv(envKeyCloudflareApiKey),
 		CloudflareZone:      os.Getenv(envKeyCloudflareZone),
 		OnChangeComment:     os.Getenv(envKeyOnChangeComment),
+		Notifiers:           parseCommaDelimited(os.Getenv(envKeyNotifiers)),
 		CheckInterval:       time.Duration(checkInterval) * time.Second,
 	}
 }

internal/helpers.go

@@ -2,10 +2,10 @@ package internal
 
 import "strings"
 
-func parseDNSToCheck(data string) []string {
+func parseCommaDelimited(data string) []string {
 	out := make([]string, 0, strings.Count(data, ",")+1)
-	for _, dns := range strings.Split(data, ",") {
-		if w := strings.TrimSpace(dns); w != "" {
+	for _, item := range strings.Split(data, ",") {
+		if w := strings.TrimSpace(item); w != "" {
 			out = append(out, w)
 		}
 	}

internal/helpers_test.go

@@ -38,8 +38,8 @@ func Test_parseDNSToCheck(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := parseDNSToCheck(tt.args.data); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("parseDNSToCheck() = %v, want %v", got, tt.want)
+			if got := parseCommaDelimited(tt.args.data); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("parseCommaDelimited() = %v, want %v", got, tt.want)
 			}
 		})
 	}

main.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/cloudflare/cloudflare-go"
 	"github.com/mkelcik/cloudflare-ddns-update/internal"
+	"github.com/mkelcik/cloudflare-ddns-update/notifications"
 	"github.com/mkelcik/cloudflare-ddns-update/public_resolvers"
 )
 
@@ -20,6 +21,8 @@ type PublicIpResolver interface {
 func getResolver(resolverName string) (PublicIpResolver, string) {
 	switch resolverName {
 	// HERE add another resolver if needed
+	case public_resolvers.CloudflareTraceTag:
+		return public_resolvers.NewDefaultCloudflareTrace(), public_resolvers.CloudflareTraceTag
 	case public_resolvers.V4IdentMeTag:
 		return public_resolvers.NewV4IdentMeDefault(), public_resolvers.V4IdentMeTag
 	case public_resolvers.IfConfigMeTag:
@@ -49,6 +52,8 @@ func main() {
 		log.Fatal(err)
 	}
 
+	notifiers := notifications.GetNotifiers(config.Notifiers)
+
 	// public ip resolver
 	publicIpResolver, resolverTag := getResolver(config.PublicIpResolverTag)
 
@@ -57,7 +62,7 @@ func main() {
 		if err != nil {
 			log.Fatal(err)
 		}
-		log.Printf("Current public ip `%s` (%s)", currentPublicIP, resolverTag)
+		log.Printf("Current public ip `%s` (resolver: %s)", currentPublicIP, resolverTag)
 
 		dns, err := allDNSRecords(ctx, api, cloudflare.ZoneIdentifier(zoneID))
 		if err != nil {
@@ -83,9 +88,19 @@ func main() {
 
 				if _, err := api.UpdateDNSRecord(ctx, cloudflare.ZoneIdentifier(zoneID), update); err != nil {
 					log.Printf("error updating dns record: %s", err)
-				} else {
-					log.Printf("Updated to `%s`", currentPublicIP)
+					continue
 				}
+
+				if err := notifiers.NotifyWithLog(ctx, notifications.Notification{
+					OldIp:       net.ParseIP(dnsRecord.Content),
+					NewIp:       currentPublicIP,
+					CheckedAt:   time.Now(),
+					ResolverTag: resolverTag,
+					Domain:      dnsRecord.Name,
+				}); err != nil {
+					log.Printf("errors in notifications: %s", err)
+				}
+				log.Printf("Updated to `%s`", currentPublicIP)
 			}
 		}
 	}

notifications/types.go

@@ -0,0 +1,76 @@
+package notifications
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+const (
+	configDelimiter = "@"
+)
+
+type Notifiers []Notifier
+
+func (n Notifiers) NotifyWithLog(ctx context.Context, notification Notification) error {
+	var outErr error
+	for _, notifier := range n {
+		if err := notifier.Notify(ctx, notification); err != nil {
+			outErr = errors.Join(outErr, err)
+			continue
+		}
+		log.Printf("Notification sent via %s\n", notifier.Tag())
+	}
+	return outErr
+}
+
+type Notification struct {
+	OldIp       net.IP    `json:"old_ip,omitempty"`
+	NewIp       net.IP    `json:"new_ip"`
+	CheckedAt   time.Time `json:"checked_at"`
+	ResolverTag string    `json:"resolver_tag"`
+	Domain      string    `json:"domain"`
+}
+
+func (n Notification) ToSlice() []string {
+	return []string{n.OldIp.String(), n.NewIp.String(), n.CheckedAt.Format(time.RFC3339), n.ResolverTag, n.Domain}
+}
+
+var Available = map[string]func(string) (Notifier, error){
+	webhookTag: func(config string) (Notifier, error) {
+		parts := strings.Split(config, configDelimiter)
+
+		if len(parts) < 2 {
+			return nil, fmt.Errorf("wrong webhook config, missing url part")
+		}
+
+		return NewWebhookNotification(WebhookConfig{Url: parts[1]}, &http.Client{
+			Timeout: 10 * time.Second,
+		}), nil
+	},
+}
+
+type Notifier interface {
+	Tag() string
+	Notify(ctx context.Context, notification Notification) error
+}
+
+func GetNotifiers(tags []string) Notifiers {
+	out := Notifiers{}
+	for _, t := range tags {
+		if initFn, ok := Available[strings.Split(t, configDelimiter)[0]]; ok {
+			notifier, err := initFn(t)
+			if err != nil {
+				log.Println(err)
+				continue
+			}
+			out = append(out, notifier)
+		}
+	}
+	return out
+}

notifications/webhook.go

@@ -0,0 +1,66 @@
+package notifications
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+const (
+	webhookTag = "webhook"
+)
+
+type Doer interface {
+	Do(*http.Request) (*http.Response, error)
+}
+
+type WebhookConfig struct {
+	Url string
+}
+
+type WebhookNotification struct {
+	config WebhookConfig
+	client Doer
+}
+
+func (w WebhookNotification) Tag() string {
+	return webhookTag
+}
+
+func NewWebhookNotification(config WebhookConfig, client Doer) *WebhookNotification {
+	return &WebhookNotification{config: config, client: client}
+}
+
+func (w WebhookNotification) getRequestBody(notification Notification) (io.Reader, error) {
+	out := bytes.NewBuffer(nil)
+	if err := json.NewEncoder(out).Encode(notification); err != nil {
+		return nil, fmt.Errorf("error encoding json notification body: %w", err)
+	}
+	return out, nil
+}
+
+func (w WebhookNotification) Notify(ctx context.Context, notification Notification) error {
+	body, err := w.getRequestBody(notification)
+	if err != nil {
+		return fmt.Errorf("WebhookNotification::NotifyWithLog error: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, w.config.Url, body)
+	if err != nil {
+		return fmt.Errorf("WebhookNotification::NotifyWithLog error creating request: %w", err)
+	}
+
+	resp, err := w.client.Do(req)
+	if err != nil {
+		return fmt.Errorf("WebhookNotification::NotifyWithLog error while sending notification: %w", err)
+	}
+	_ = resp.Body.Close()
+
+	if resp.StatusCode >= 300 {
+		return fmt.Errorf("WebhookNotification::NotifyWithLog unexpected non 2xx code %d returned", resp.StatusCode)
+	}
+	return nil
+}

public_resolvers/base_resolver.go

@@ -2,19 +2,30 @@ package public_resolvers
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net"
 	"net/http"
 )
 
+var NoIPInResponseError = errors.New("no ip found in response")
+
 type Doer interface {
 	Do(*http.Request) (*http.Response, error)
 }
 
+type ipParserFunc func(reader io.Reader) (string, error)
+
+func defaultIpParser(reader io.Reader) (string, error) {
+	out, err := io.ReadAll(reader)
+	return string(out), err
+}
+
 type baseResolver struct {
-	client Doer
-	url    string
+	client   Doer
+	url      string
+	ipParser ipParserFunc
 }
 
 func (i baseResolver) ResolvePublicIp(ctx context.Context) (net.IP, error) {
@@ -35,10 +46,10 @@ func (i baseResolver) ResolvePublicIp(ctx context.Context) (net.IP, error) {
 		return net.IP{}, fmt.Errorf("unexpected response code %d", resp.StatusCode)
 	}
 
-	ipText, err := io.ReadAll(resp.Body)
+	ipText, err := i.ipParser(resp.Body)
 	if err != nil {
 		return net.IP{}, fmt.Errorf("error reading body: %w", err)
 	}
 
-	return net.ParseIP(string(ipText)), nil
+	return net.ParseIP(ipText), nil
 }

public_resolvers/base_resolver_test.go

@@ -21,7 +21,7 @@ func (f RoundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
 // NewTestClient returns *http.Client with Transport replaced to avoid making real calls
 func NewTestClient(fn RoundTripFunc) *http.Client {
 	return &http.Client{
-		Transport: RoundTripFunc(fn),
+		Transport: fn,
 	}
 }
 
@@ -54,6 +54,7 @@ func Test_baseResolver_ResolvePublicIp(t *testing.T) {
 	type fields struct {
 		client Doer
 		url    string
+		fn     ipParserFunc
 	}
 	type args struct {
 		ctx context.Context
@@ -70,6 +71,7 @@ func Test_baseResolver_ResolvePublicIp(t *testing.T) {
 			fields: fields{
 				client: client,
 				url:    testUrl,
+				fn:     defaultIpParser,
 			},
 			args: args{
 				ctx: context.Background(),
@@ -81,8 +83,9 @@ func Test_baseResolver_ResolvePublicIp(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			i := baseResolver{
-				client: tt.fields.client,
-				url:    tt.fields.url,
+				client:   tt.fields.client,
+				url:      tt.fields.url,
+				ipParser: tt.fields.fn,
 			}
 			got, err := i.ResolvePublicIp(tt.args.ctx)
 			if (err != nil) != tt.wantErr {

public_resolvers/cloudflare_trace.go

@@ -0,0 +1,49 @@
+package public_resolvers
+
+import (
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+const (
+	CloudflareTraceTag = "1.1.1.1"
+	CloudflareTraceUrl = "https://1.1.1.1/cdn-cgi/trace"
+
+	ipPrefix = "ip="
+)
+
+type CloudflareTrace struct {
+	baseResolver
+}
+
+func NewDefaultCloudflareTrace() *CloudflareTrace {
+	return NewCloudflareTrace(&http.Client{
+		Timeout: 10 * time.Second,
+	})
+}
+
+func cloudflareTraceResponseParser(reader io.Reader) (string, error) {
+	data, err := io.ReadAll(reader)
+	if err != nil {
+		return "", err
+	}
+
+	for _, row := range strings.Split(string(data), "\n") {
+		if strings.Index(row, ipPrefix) == 0 {
+			return strings.TrimSpace(strings.ReplaceAll(row, ipPrefix, "")), nil
+		}
+	}
+	return "", NoIPInResponseError
+}
+
+func NewCloudflareTrace(client Doer) *CloudflareTrace {
+	return &CloudflareTrace{
+		baseResolver: baseResolver{
+			client:   client,
+			url:      CloudflareTraceUrl,
+			ipParser: cloudflareTraceResponseParser,
+		},
+	}
+}

public_resolvers/cloudflare_trace_test.go

@@ -0,0 +1,78 @@
+package public_resolvers
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+func Test_cloudflareTraceResponseParser(t *testing.T) {
+
+	type args struct {
+		reader io.Reader
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    string
+		wantErr bool
+	}{
+		{
+			name: "ok",
+			args: args{
+				reader: bytes.NewBuffer([]byte(`fl=31f118
+h=1.1.1.1
+ip=94.113.142.206
+ts=1683145336.383
+visit_scheme=https
+uag=Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36
+colo=PRG
+sliver=none
+http=http/2
+loc=CZ
+tls=TLSv1.3
+sni=off
+warp=off
+gateway=off
+rbi=off
+kex=X25519`)),
+			},
+			want:    "94.113.142.206",
+			wantErr: false,
+		},
+		{
+			name: "no ip in response",
+			args: args{
+				reader: bytes.NewBuffer([]byte(`fl=31f118
+h=1.1.1.1
+ts=1683145336.383
+visit_scheme=https
+uag=Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36
+colo=PRG
+sliver=none
+http=http/2
+loc=CZ
+tls=TLSv1.3
+sni=off
+warp=off
+gateway=off
+rbi=off
+kex=X25519`)),
+			},
+			want:    "",
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := cloudflareTraceResponseParser(tt.args.reader)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("cloudflareTraceResponseParser() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("cloudflareTraceResponseParser() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

public_resolvers/ifconfigme.go

@@ -23,8 +23,9 @@ func NewDefaultIfConfigMe() *IfConfigMe {
 func NewIfConfigMe(client Doer) *IfConfigMe {
 	return &IfConfigMe{
 		baseResolver: baseResolver{
-			client: client,
-			url:    ifConfigMeUrl,
+			client:   client,
+			url:      ifConfigMeUrl,
+			ipParser: defaultIpParser,
 		},
 	}
 }

public_resolvers/v4identme.go

@@ -23,8 +23,9 @@ func NewV4IdentMeDefault() *V4IdentMe {
 func NewV4IdentMe(client Doer) *V4IdentMe {
 	return &V4IdentMe{
 		baseResolver: baseResolver{
-			client: client,
-			url:    v4IdentMeUrl,
+			client:   client,
+			url:      v4IdentMeUrl,
+			ipParser: defaultIpParser,
 		},
 	}
 }