fix(dev): address CLI review feedback

tools/homarr-dev/internal/docker/docker.go

@@ -12,6 +12,8 @@ import (
 	"strings"
 )
 
+const defaultDevelopmentEncryptionKey = "cdca265c289df60f6605a2fc9c43cfa8eb6efdc98b203cad2c3f2970aca09fbe"
+
 type Container struct {
 	ID     string
 	Name   string
@@ -82,8 +84,12 @@ func List() ([]Container, error) {
 }
 
 func FindFreePort(start int) int {
+	if start > 65535 {
+		return 0
+	}
 	used := usedDockerPorts()
-	for port := start; ; port++ {
+	start = max(start, 1)
+	for port := start; port <= 65535; port++ {
 		if used[port] {
 			continue
 		}
@@ -93,36 +99,43 @@ func FindFreePort(start int) int {
 			return port
 		}
 	}
+	return 0
 }
 
 func usedDockerPorts() map[int]bool {
-	used := make(map[int]bool)
 	out, err := exec.Command("docker", "ps", "--format", "{{.Ports}}").Output()
 	if err != nil {
-		return used
+		return make(map[int]bool)
 	}
-	for _, mapping := range strings.Split(string(out), ",") {
-		left, _, found := strings.Cut(mapping, "->")
-		if !found {
-			continue
-		}
-		colon := strings.LastIndex(left, ":")
-		if colon < 0 {
-			continue
-		}
-		ports := strings.SplitN(strings.TrimSpace(left[colon+1:]), "-", 2)
-		first, err := strconv.Atoi(ports[0])
-		if err != nil {
-			continue
-		}
-		last := first
-		if len(ports) == 2 {
-			if parsed, err := strconv.Atoi(ports[1]); err == nil {
-				last = parsed
+	return parseUsedDockerPorts(out)
+}
+
+func parseUsedDockerPorts(out []byte) map[int]bool {
+	used := make(map[int]bool)
+	for _, line := range strings.Split(string(out), "\n") {
+		for _, mapping := range strings.Split(line, ",") {
+			left, _, found := strings.Cut(mapping, "->")
+			if !found {
+				continue
+			}
+			colon := strings.LastIndex(left, ":")
+			if colon < 0 {
+				continue
+			}
+			ports := strings.SplitN(strings.TrimSpace(left[colon+1:]), "-", 2)
+			first, err := strconv.Atoi(ports[0])
+			if err != nil {
+				continue
+			}
+			last := first
+			if len(ports) == 2 {
+				if parsed, err := strconv.Atoi(ports[1]); err == nil {
+					last = parsed
+				}
+			}
+			for port := first; port <= last; port++ {
+				used[port] = true
 			}
-		}
-		for port := first; port <= last; port++ {
-			used[port] = true
 		}
 	}
 	return used
@@ -162,8 +175,12 @@ func Start(opts StartOptions) error {
 
 	_ = exec.Command("docker", "rm", "-f", opts.Name).Run()
 
+	encryptionKey := os.Getenv("HOMARR_DEV_SECRET_ENCRYPTION_KEY")
+	if encryptionKey == "" {
+		encryptionKey = defaultDevelopmentEncryptionKey
+	}
 	args := []string{"run", "--rm", "--name", opts.Name,
-		"-e", "SECRET_ENCRYPTION_KEY=cdca265c289df60f6605a2fc9c43cfa8eb6efdc98b203cad2c3f2970aca09fbe",
+		"-e", "SECRET_ENCRYPTION_KEY=" + encryptionKey,
 	}
 	if opts.Platform != "" {
 		args = append(args, "--platform", opts.Platform)

tools/homarr-dev/internal/docker/docker_test.go

@@ -25,3 +25,18 @@ func TestIsPortConflict(t *testing.T) {
 		t.Fatal("manifest error classified as port conflict")
 	}
 }
+
+func TestParseUsedDockerPortsPreservesLineBoundaries(t *testing.T) {
+	ports := parseUsedDockerPorts([]byte("6379/tcp\n0.0.0.0:7575->7575/tcp, [::]:7575->7575/tcp\n0.0.0.0:8000-8002->8000-8002/tcp\n"))
+	for _, port := range []int{7575, 8000, 8001, 8002} {
+		if !ports[port] {
+			t.Fatalf("port %d was not detected", port)
+		}
+	}
+}
+
+func TestFindFreePortRejectsOutOfRangeStart(t *testing.T) {
+	if port := FindFreePort(65536); port != 0 {
+		t.Fatalf("port = %d, want 0", port)
+	}
+}

tools/homarr-dev/internal/docker/images.go

@@ -56,8 +56,8 @@ func parseImageList(output []byte) ([]Image, error) {
 	return images, nil
 }
 
-func ListLocalImages() ([]Image, error) {
-	out, err := exec.Command("docker", "image", "ls", "--filter", "reference=homarr:*", "--format", "{{json .}}").Output()
+func ListLocalImages(ctx context.Context) ([]Image, error) {
+	out, err := exec.CommandContext(ctx, "docker", "image", "ls", "--filter", "reference=homarr:*", "--format", "{{json .}}").Output()
 	if err != nil {
 		return nil, fmt.Errorf("list local Homarr images: %w", err)
 	}
@@ -65,7 +65,7 @@ func ListLocalImages() ([]Image, error) {
 	if err != nil {
 		return nil, err
 	}
-	labelsByImage, err := inspectImageLabels(images)
+	labelsByImage, err := inspectImageLabels(ctx, images)
 	if err != nil {
 		return nil, err
 	}
@@ -77,7 +77,7 @@ func ListLocalImages() ([]Image, error) {
 	return images, nil
 }
 
-func inspectImageLabels(images []Image) ([]map[string]string, error) {
+func inspectImageLabels(ctx context.Context, images []Image) ([]map[string]string, error) {
 	if len(images) == 0 {
 		return nil, nil
 	}
@@ -85,7 +85,7 @@ func inspectImageLabels(images []Image) ([]map[string]string, error) {
 	for _, image := range images {
 		args = append(args, image.Reference())
 	}
-	out, err := exec.Command("docker", args...).Output()
+	out, err := exec.CommandContext(ctx, "docker", args...).Output()
 	if err != nil {
 		return nil, fmt.Errorf("inspect local Homarr images: %w", err)
 	}
@@ -135,10 +135,6 @@ func BuildCommand(ctx context.Context, options BuildOptions) (*exec.Cmd, error)
 	return command, nil
 }
 
-func Build(options BuildOptions) error {
-	return BuildContext(context.Background(), options, os.Stdout, os.Stderr)
-}
-
 func BuildContext(ctx context.Context, options BuildOptions, stdout, stderr io.Writer) error {
 	command, err := BuildCommand(ctx, options)
 	if err != nil {

tools/homarr-dev/internal/docker/images_test.go

@@ -17,7 +17,7 @@ func TestParseImageListFiltersHomarrTags(t *testing.T) {
 }
 
 func TestInspectImageLabelsWithNoImages(t *testing.T) {
-	labels, err := inspectImageLabels(nil)
+	labels, err := inspectImageLabels(t.Context(), nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -53,7 +53,7 @@ func TestListLocalImagesIntegration(t *testing.T) {
 	if wantTag == "" {
 		t.Skip("set HOMARR_TEST_LOCAL_IMAGE to a local homarr image tag")
 	}
-	images, err := ListLocalImages()
+	images, err := ListLocalImages(t.Context())
 	if err != nil {
 		t.Fatal(err)
 	}