Allow dots in app names (closes #260)

App names may now contain dots, such as sneak.berlin: runs of
lowercase letters and numbers joined by single dots or by hyphens,
2 to 63 characters. Docker accepts every such name in the app's image
name, upaas-<name>; a dot needs a letter or number on both sides
because Docker requires it. The rule also keeps a dot off either end,
so the name is safe as a directory and log file name.

The new and edit app forms use the same pattern. Their old one was not
a valid regular expression under the flag browsers compile it with, so
browsers ignored it.

A test deploys an app named sneak.berlin against the fake Docker API
and checks the image and container names with Docker's own rules.

Model: opus-5-5

internal/handlers/app_name_validation.go

@@ -13,12 +13,15 @@ const (
 	appNameMaxLength = 63
 )
 
-// validAppNameRe matches names containing only lowercase alphanumeric characters and
-// hyphens, starting and ending with an alphanumeric character.
-var validAppNameRe = regexp.MustCompile(`^[a-z0-9][a-z0-9-]*[a-z0-9]$`)
+// validAppNameRe matches runs of lowercase letters and digits joined by
+// single dots or by hyphens, such as "my-app" or "sneak.berlin". Docker
+// accepts every name it allows as the app's image name, upaas-<name>; a
+// dot needs a letter or digit on both sides because Docker requires it.
+// It also keeps the name from being "." or ".." or starting or ending
+// with a dot, so it is safe as a directory and file name. The pattern
+// attribute of the name field on the new and edit app forms is the same.
+var validAppNameRe = regexp.MustCompile(`^[a-z0-9]+((\.|-+)[a-z0-9]+)*$`)
 
-// validateAppName checks that the given app name is safe for use in Docker
-// container names, image tags, and file system paths.
 var (
 	errAppNameLength = errors.New(
 		"app name must be between " +
@@ -26,11 +29,14 @@ var (
 			strconv.Itoa(appNameMaxLength) + " characters",
 	)
 	errAppNamePattern = errors.New(
-		"app name must contain only lowercase letters, numbers, " +
-			"and hyphens, and must start and end with a letter or number",
+		"app name must contain only lowercase letters, numbers, hyphens, " +
+			"and dots, must start and end with a letter or number, " +
+			"and must have a letter or number on both sides of each dot",
 	)
 )
 
+// validateAppName checks that the given app name is safe for use in Docker
+// container names, image tags, and file system paths.
 func validateAppName(name string) error {
 	if len(name) < appNameMinLength || len(name) > appNameMaxLength {
 		return errAppNameLength

internal/handlers/app_name_validation_test.go

@@ -18,6 +18,10 @@ func TestValidateAppName(t *testing.T) {
 		{"valid two chars", "ab", false},
 		{"valid complex", "my-cool-app-v2", false},
 		{"valid all numbers", "123", false},
+		{"valid double hyphen", "my--app", false},
+		{"valid domain", "sneak.berlin", false},
+		{"valid two dots", "www.sneak.berlin", false},
+		{"valid dot and hyphen", "my-app.example.com", false},
 		{"empty", "", true},
 		{"single char", "a", true},
 		{"too long", "a" + string(make([]byte, 63)), true},
@@ -36,7 +40,12 @@ func TestValidateAppName(t *testing.T) {
 		{"starts with hyphen", "-myapp", true},
 		{"ends with hyphen", "myapp-", true},
 		{"underscore", "my_app", true},
-		{"dot", "my.app", true},
+		{"two dots in a row", "a..b", true},
+		{"starts with dot", ".a", true},
+		{"ends with dot", "a.", true},
+		{"only dots", "..", true},
+		{"hyphen before dot", "a-.b", true},
+		{"hyphen after dot", "a.-b", true},
 		{"slash", "my/app", true},
 		{"path traversal", "../etc/passwd", true},
 		{"special chars", "app@name!", true},

internal/service/deploy/deploy_app_name_test.go

@@ -0,0 +1,57 @@
+package deploy_test
+
+import (
+	"context"
+	"slices"
+	"testing"
+
+	"github.com/distribution/reference"
+	"github.com/docker/docker/daemon/names"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"sneak.berlin/go/upaas/internal/models"
+)
+
+// TestDeployAppWithDotInName deploys an app named sneak.berlin against a
+// fake Docker API and checks that Docker accepts the names of the image it
+// builds and of the container it runs, using Docker's own rules for each.
+func TestDeployAppWithDotInName(t *testing.T) {
+	t.Parallel()
+
+	api := &fakeImageAPI{
+		images:   map[string][]string{},
+		shortSHA: "abc1234",
+		nextID:   "sha256:built",
+	}
+	svc, db := newImageTestService(t, api)
+	ctx := context.Background()
+
+	app := saveApp(t, db, "sneak.berlin", "", "")
+
+	deployment := models.NewDeployment(db)
+	deployment.AppID = app.ID
+	require.NoError(t, deployment.Save(ctx))
+
+	imageID, err := svc.BuildImage(ctx, app, deployment)
+	require.NoError(t, err)
+	require.NoError(t, svc.DeployContainer(ctx, app, deployment, imageID))
+
+	images, _ := api.state()
+
+	api.mu.Lock()
+	containers := slices.Clone(api.containers)
+	api.mu.Unlock()
+
+	require.Equal(t, map[string][]string{
+		"sha256:built": {"upaas-sneak.berlin:abc1234"},
+	}, images)
+
+	_, err = reference.ParseNormalizedNamed("upaas-sneak.berlin:abc1234")
+	require.NoError(t, err)
+
+	require.Equal(t, []string{"upaas-sneak.berlin"}, containers)
+	assert.Regexp(t, names.RestrictedNamePattern, containers[0])
+
+	assert.DirExists(t, svc.GetBuildDirExported(app.Name))
+}

internal/service/deploy/deploy_images_test.go

@@ -35,12 +35,13 @@ import (
 // an image's last tag, or an untagged image by its ID, deletes the image.
 // It also answers the steps of a git clone that reports shortSHA.
 type fakeImageAPI struct {
-	mu       sync.Mutex
-	images   map[string][]string // image ID -> tags
-	shortSHA string              // the commit's short hash the clone reports
-	nextID   string              // ID of the image the next build creates
-	removed  []string            // each tag or ID removed
-	forced   bool                // whether a removal was forced
+	mu         sync.Mutex
+	images     map[string][]string // image ID -> tags
+	shortSHA   string              // the commit's short hash the clone reports
+	nextID     string              // ID of the image the next build creates
+	removed    []string            // each tag or ID removed
+	forced     bool                // whether a removal was forced
+	containers []string            // name of each named container created
 }
 
 func (api *fakeImageAPI) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -67,6 +68,11 @@ func (api *fakeImageAPI) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	case strings.HasSuffix(r.URL.Path, "/version"):
 		_, _ = w.Write([]byte(`{"Version":"27.3.1","ApiVersion":"1.47"}`))
 	case strings.HasSuffix(r.URL.Path, "/containers/create"):
+		// The git clone's container has no name; the app's has.
+		if containerName := r.URL.Query().Get("name"); containerName != "" {
+			api.containers = append(api.containers, containerName)
+		}
+
 		_, _ = w.Write([]byte(`{"Id":"gitcontainer"}`))
 	case strings.HasSuffix(r.URL.Path, "/logs"):
 		writeCloneOutput(w, api.shortSHA)

internal/service/deploy/export_test.go

@@ -113,6 +113,16 @@ func (svc *Service) BuildImage(
 	return svc.buildImage(ctx, app, deployment)
 }
 
+// DeployContainer exposes deployContainerWithTimeout for testing.
+func (svc *Service) DeployContainer(
+	ctx context.Context,
+	app *models.App,
+	deployment *models.Deployment,
+	imageID docker.ImageID,
+) error {
+	return svc.deployContainerWithTimeout(ctx, app, deployment, imageID)
+}
+
 // BuildContainerOptionsExported exposes buildContainerOptions for testing.
 func (svc *Service) BuildContainerOptionsExported(
 	ctx context.Context,