ci: only deploy on relevant code changes

Reduction of 352 MiB -> 8.22 MiB

Reviewed-on: #29
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

.gitea/workflows/cd.yaml

@@ -9,6 +9,27 @@ env:
   DOCKER_REGISTRY: gitea.t000-n.de
 
 jobs:
+  check-changes:
+    name: Check changes
+    runs-on: ubuntu-latest
+    outputs:
+      changes: ${{ steps.filter.outputs.code }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Get changes
+        id: filter
+        uses: dorny/paths-filter@v3
+        with:
+          filters: |
+            code:
+              - 'go.mod'
+              - 'go.sum'
+              - '**/*.go'
+              - 'config.example.yaml'
+              - 'Dockerfile'
+              - 'Makefile'
+
   test:
     name: test
     runs-on: ubuntu-latest
@@ -44,18 +65,58 @@ jobs:
 
   build_and_push:
     name: Build and push
+    strategy:
+      matrix:
+        arch: [amd64, arm64]
     needs:
       - test
+      - check-changes
+    if: ${{ needs.check-changes.outputs.code == 'true' }}
+    runs-on:
+      - ubuntu-latest
+      - linux_${{ matrix.arch }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+      - name: Login to Registry
+        uses: docker/login-action@v2
+        with:
+          registry: ${{ env.DOCKER_REGISTRY }}
+          username: ${{ secrets.REGISTRY_USER }}
+          password: ${{ secrets.REGISTRY_PASSWORD }}
+      - name: Get Metadata
+        id: meta
+        run: |
+          echo REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F"/" '{print $2}' | tr '[:upper:]' '[:lower:]') >> $GITHUB_OUTPUT
+          echo REPO_VERSION=$(git describe --tags --always | sed 's/^v//') >> $GITHUB_OUTPUT
+      - name: Build and push
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/${{ matrix.arch }}
+          push: true
+          provenance: false
+          build-args: GOARCH=${{ matrix.arch }}
+          tags: |
+            ${{ env.DOCKER_REGISTRY }}/t.behrendt/${{ steps.meta.outputs.REPO_NAME }}:${{ steps.meta.outputs.REPO_VERSION }}-${{ matrix.arch }}
+
+  create_manifest:
+    name: Create manifest
+    needs:
+      - build_and_push
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Set up QEMU
+      - name: Get Metadata
-        uses: docker/setup-qemu-action@v2
+        id: meta
-
+        run: |
-      - name: Set up Docker Buildx
+          echo REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F"/" '{print $2}' | tr '[:upper:]' '[:lower:]') >> $GITHUB_OUTPUT
-        uses: docker/setup-buildx-action@v2
+          echo REPO_VERSION=$(git describe --tags --always | sed 's/^v//') >> $GITHUB_OUTPUT
 
       - name: Login to Registry
         uses: docker/login-action@v2
@@ -64,21 +125,10 @@ jobs:
           username: ${{ secrets.REGISTRY_USER }}
           password: ${{ secrets.REGISTRY_PASSWORD }}
 
-      - name: Get Metadata
+      - name: Create manifest
-        id: meta
         run: |
-          echo REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F"/" '{print $2}' | tr '[:upper:]' '[:lower:]') >> $GITHUB_OUTPUT
+          docker manifest create ${{ env.DOCKER_REGISTRY }}/t.behrendt/${{ steps.meta.outputs.REPO_NAME }}:latest \
-          echo REPO_VERSION=$(git describe --tags --always | sed 's/^v//') >> $GITHUB_OUTPUT
+            ${{ env.DOCKER_REGISTRY }}/t.behrendt/${{ steps.meta.outputs.REPO_NAME }}:${{ steps.meta.outputs.REPO_VERSION }}-amd64 \
+            ${{ env.DOCKER_REGISTRY }}/t.behrendt/${{ steps.meta.outputs.REPO_NAME }}:${{ steps.meta.outputs.REPO_VERSION }}-arm64
 
-      - name: Build and push
+          docker manifest push ${{ env.DOCKER_REGISTRY }}/t.behrendt/${{ steps.meta.outputs.REPO_NAME }}:latest
-        uses: docker/build-push-action@v4
-        with:
-          context: .
-          file: ./Dockerfile
-          platforms: |
-            linux/amd64
-            linux/arm64
-          push: true
-          tags: |
-            ${{ env.DOCKER_REGISTRY }}/t.behrendt/${{ steps.meta.outputs.REPO_NAME }}:${{ steps.meta.outputs.REPO_VERSION }}
-            ${{ env.DOCKER_REGISTRY }}/t.behrendt/${{ steps.meta.outputs.REPO_NAME }}:latest

Dockerfile

@@ -1,13 +1,14 @@
-FROM golang:1.23-alpine
+FROM golang:1.23-alpine as build
+
+ARG GOARCH=amd64
 
 WORKDIR /app
-
 COPY go.mod go.sum ./
-
 RUN go mod download
-
 COPY . .
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=${GOARCH} \
+    go build -trimpath -ldflags="-s -w" -o main .
 
-RUN go build -o main .
+FROM gcr.io/distroless/static-debian12
-
+COPY --from=build /app/main /
-CMD ["./main"]
+CMD ["/main"]

README.md

@@ -38,6 +38,7 @@ domains:
       - www
 check_interval: 0 0 0/6 * * * *
 mode: Scheduled
+log_level: info
 ```
 
 The config file is expected to be in the same directory as the binary and called `config.yaml`. For the OCR image, the root directory is `/app`.

config.example.yaml

@@ -21,3 +21,4 @@ domains:
       - www
 check_interval: 0 0 0/6 * * * *
 mode: Scheduled
+log_level: info

main.go

@@ -2,6 +2,9 @@ package main
 
 import (
 	"fmt"
+	"log/slog"
+	"os"
+	"strings"
 
 	"realdnydns/pkg/config"
 	"realdnydns/pkg/dnsProvider"
@@ -15,48 +18,84 @@ import (
 )
 
 func main() {
+	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+	}))
+
 	configClient := config.Config{}
 	err := configClient.Load("config.yaml")
 	if err != nil {
+		logger.Error("Failed to load config file", slog.String("error", err.Error()))
 		panic(err)
 	}
 
+	if configClient.LogLevel != "" {
+		logger = slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
+			Level: slog.Level(config.LogLevelMap[strings.ToLower(configClient.LogLevel)]),
+		}))
+	}
+
 	var externalIpProvider externalIpProvider.ExternalIpProvider
 	switch configClient.ExternalIPProvider.Type {
 	case "plain":
+		logger.Info("Using plain external IP provider", slog.String("external_ip_provider", "plain"))
+
 		var plainConfig plainExternalIpProvider.PlainExternalIpProviderConfig
 		err := configClient.ExternalIPProvider.ProviderConfig.Decode(&plainConfig)
 		if err != nil {
+			logger.Error("Failed to create config",
+				slog.String("external_ip_provider", "plain"),
+				slog.String("error", err.Error()),
+			)
 			panic(err)
 		}
 
 		externalIpProvider, err = plainExternalIpProvider.New(plainConfig)
 		if err != nil {
+			logger.Error("Failed to create plain external IP provider",
+				slog.String("external_ip_provider", "plain"),
+				slog.String("error", err.Error()),
+			)
 			panic(err)
 		}
 	default:
+		logger.Error("Unknown external IP provider", slog.String("external_ip_provider", configClient.ExternalIPProvider.Type))
 		panic(fmt.Errorf("unknown external IP provider: %s", configClient.ExternalIPProvider.Type))
 	}
 
 	var dnsProvider dnsProvider.DNSProvider
 	switch configClient.DNSProvider.Type {
 	case "ionos":
+		logger.Info("Using IONOS DNS provider", slog.String("dns_provider", "ionos"))
+
 		var ionosConfig ionos.IONOSConfig
 		err := configClient.DNSProvider.ProviderConfig.Decode(&ionosConfig)
 		if err != nil {
+			logger.Error("Failed to create IONOS DNS provider",
+				slog.String("dns_provider", "ionos"),
+				slog.String("error", err.Error()),
+			)
 			panic(err)
 		}
+
 		dnsProvider, err = ionos.NewIonos(&ionosConfig)
 		if err != nil {
+			logger.Error("Failed to create IONOS DNS provider",
+				slog.String("dns_provider", "ionos"),
+				slog.String("error", err.Error()),
+			)
 			panic(err)
 		}
 	default:
+		logger.Error("Unknown DNS provider", slog.String("dns_provider", configClient.DNSProvider.Type))
 		panic(fmt.Errorf("unknown DNS provider: %s", configClient.DNSProvider.Type))
 	}
 
 	var notificationProvider notificationProvider.NotificationProvider
 	switch configClient.NotificationProvider.Type {
 	case "gotify":
+		logger.Info("Using Gotify notification provider", slog.String("notification_provider", "gotify"))
+
 		var gotifyConfig gotify.NotificationProviderImplGotifyConfig
 		err := configClient.NotificationProvider.ProviderConfig.Decode(&gotifyConfig)
 		if err != nil {
@@ -65,29 +104,39 @@ func main() {
 
 		notificationProvider, err = gotify.New(gotifyConfig)
 		if err != nil {
+			logger.Error("Failed to create Gotify notification provider",
+				slog.String("notification_provider", "gotify"),
+				slog.String("error", err.Error()),
+			)
 			panic(err)
 		}
 	default:
+		logger.Info("Using console notification provider", slog.String("notification_provider", "console"))
+
 		notificationProvider = notificationProviderConsole.New()
 	}
 
-	rdd := realDynDns.New(externalIpProvider, dnsProvider, notificationProvider, configClient.Domains)
+	rdd := realDynDns.New(externalIpProvider, dnsProvider, notificationProvider, configClient.Domains, logger.With(slog.String("service", "realDynDns")))
 
 	switch configClient.Mode {
 	case config.ScheduledMode:
+		logger.Info("Running in scheduled mode", slog.String("interval", configClient.CheckInterval))
+
 		schedule, job, err := rdd.RunWithSchedule(configClient.CheckInterval)
 		if err != nil {
+			logger.Error("Failed to create scheduler", slog.String("error", err.Error()))
 			panic(err)
 		}
 
-		fmt.Println("Starting scheduler")
+		logger.Info("Next run:", slog.String("time", job.NextRun().String()))
-		fmt.Println("Next run:", job.NextRun())
 		schedule.StartBlocking()
 	case config.RunOnceMode:
-		numberOfChanges, err := rdd.RunOnce()
+		logger.Info("Running in run once mode")
+
+		_, err := rdd.RunOnce()
 		if err != nil {
+			logger.Error("Failed to run once", slog.String("error", err.Error()))
 			panic(err)
 		}
-		fmt.Println("Number of changes:", numberOfChanges)
 	}
 }

pkg/config/config.go

@@ -3,7 +3,9 @@ package config
 import (
 	"errors"
 	"fmt"
+	"log/slog"
 	"os"
+	"strings"
 
 	"gopkg.in/yaml.v3"
 )
@@ -15,6 +17,7 @@ type Config struct {
 	NotificationProvider NotificationProviderConfig `yaml:"notification_provider,omitempty"`
 	Domains              []DomainConfig             `yaml:"domains"`
 	CheckInterval        string                     `yaml:"check_interval"`
+	LogLevel             string                     `yaml:"log_level"`
 }
 
 const (
@@ -22,6 +25,18 @@ const (
 	ScheduledMode = "Scheduled"
 )
 
+var LogLevelMap = map[string]slog.Level{
+	"debug": slog.LevelDebug,
+	"info":  slog.LevelInfo,
+	"warn":  slog.LevelWarn,
+	"error": slog.LevelError,
+}
+
+func isValidLogLevel(level string) bool {
+	_, ok := LogLevelMap[strings.ToLower(level)]
+	return ok
+}
+
 type DomainConfig struct {
 	TLD        string   `yaml:"tld"`
 	Subdomains []string `yaml:"subdomains"`
@@ -68,5 +83,9 @@ func (c *Config) validate() error {
 		return errors.New("check interval must be set when mode is 'Scheduled'")
 	}
 
+	if c.LogLevel != "" && !isValidLogLevel(c.LogLevel) {
+		return fmt.Errorf("log level must be one of 'debug', 'info', 'warn', 'error', but got %s", c.LogLevel)
+	}
+
 	return nil
 }

pkg/realDynDns/realDynDns.go

@@ -2,6 +2,8 @@ package realDynDns
 
 import (
 	"fmt"
+	"log/slog"
+	"sync"
 	"time"
 
 	"realdnydns/pkg/config"
@@ -17,6 +19,7 @@ type ChangeDetector struct {
 	dnsProvider          dnsProvider.DNSProvider
 	notificationProvider notificationProvider.NotificationProvider
 	domains              []config.DomainConfig
+	logger               *slog.Logger
 }
 
 func New(
@@ -24,12 +27,14 @@ func New(
 	dnsProvider dnsProvider.DNSProvider,
 	notificationProvider notificationProvider.NotificationProvider,
 	domains []config.DomainConfig,
+	logger *slog.Logger,
 ) ChangeDetector {
 	return ChangeDetector{
 		externalIpProvider:   externalIpProvider,
 		dnsProvider:          dnsProvider,
 		notificationProvider: notificationProvider,
 		domains:              domains,
+		logger:               logger,
 	}
 }
 
@@ -58,37 +63,90 @@ func (c *ChangeDetector) RunOnce() (int, error) {
 }
 
 func (c *ChangeDetector) detectAndApplyChanges() (int, error) {
+	c.logger.Info("Detecting and applying changes")
+
 	externalIp, err := c.externalIpProvider.GetExternalIp()
 	if err != nil {
+		c.logger.Error("Failed to retrieve external IP", slog.String("error", err.Error()))
 		return 0, err
 	}
 
-	var numberUpdated int
+	var wg sync.WaitGroup
+
+	numberUpdatedChannel := make(chan int)
 
 	for _, domain := range c.domains {
 		for _, subdomain := range domain.Subdomains {
-			currentRecord, err := c.dnsProvider.GetRecord(domain.TLD, subdomain)
+			wg.Add(1)
-			if err != nil {
-				return numberUpdated, err
-			}
 
-			if currentRecord.IP != externalIp.String() {
+			go func(domain config.DomainConfig, subdomain string) {
-				err = c.notificationProvider.SendNotification(
+				defer wg.Done()
-					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()),
+				c.logger.Info("Checking record",
+					slog.String("tld", domain.TLD),
+					slog.String("subdomain", subdomain),
 				)
+				currentRecord, err := c.dnsProvider.GetRecord(domain.TLD, subdomain)
 				if err != nil {
-					return numberUpdated, err
+					c.logger.Error("Failed to retrieve record",
+						slog.String("error", err.Error()),
+						slog.String("tld", domain.TLD),
+						slog.String("subdomain", subdomain),
+					)
+					return
 				}
 
-				_, err = c.dnsProvider.UpdateRecord(domain.TLD, subdomain, externalIp, currentRecord.TTL, currentRecord.Prio, currentRecord.Disabled)
+				if currentRecord.IP != externalIp.String() {
-				numberUpdated++
+					c.logger.Info("Record has changed",
-				if err != nil {
+						slog.String("tld", domain.TLD),
-					return numberUpdated, err
+						slog.String("subdomain", subdomain),
+						slog.String("current_ip", currentRecord.IP),
+						slog.String("external_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 {
+						c.logger.Warn("Failed to send notification",
+							slog.String("error", err.Error()),
+						)
+						return
+					}
+
+					c.logger.Info("Updating record",
+						slog.String("tld", domain.TLD),
+						slog.String("subdomain", subdomain),
+						slog.String("current_ip", currentRecord.IP),
+						slog.String("external_ip", externalIp.String()),
+					)
+					_, err = c.dnsProvider.UpdateRecord(domain.TLD, subdomain, externalIp, currentRecord.TTL, currentRecord.Prio, currentRecord.Disabled)
+					if err != nil {
+						c.logger.Error("Failed to update record",
+							slog.String("error", err.Error()),
+							slog.String("tld", domain.TLD),
+							slog.String("subdomain", subdomain),
+						)
+						return
+					}
+
+					numberUpdatedChannel <- 1
 				}
-			}
+			}(domain, subdomain)
 		}
 	}
 
+	go func() {
+		wg.Wait()
+		close(numberUpdatedChannel)
+	}()
+
+	numberUpdated := 0
+	for v := range numberUpdatedChannel {
+		numberUpdated += v
+	}
+
+	c.logger.Info("Run completed", slog.Int("number_of_changes", numberUpdated))
 	return numberUpdated, nil
 }

pkg/realDynDns/realDynDns_test.go

@@ -1,6 +1,7 @@
 package realDynDns
 
 import (
+	"log/slog"
 	"net"
 	"realdnydns/model/common"
 	"realdnydns/pkg/config"
@@ -72,7 +73,9 @@ func testDetectAndApplyChangesWithChanges() func(t *testing.T) {
 						"@",
 					},
 				},
-			})
+			},
+			slog.Default(),
+		)
 
 		numberUpdated, err := changeDetector.RunOnce()
 		if err != nil {
@@ -101,7 +104,9 @@ func testDetectAndApplyChangesWithoutChanges() func(t *testing.T) {
 						"@",
 					},
 				},
-			})
+			},
+			slog.Default(),
+		)
 
 		numberUpdated, err := changeDetector.RunOnce()
 		if err != nil {

renovate.json

@@ -0,0 +1,3 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json"
+}