Show the deploy branch in the app page title (closes #240)

The app page shows the app's configured branch as a neutral label next
to the status badge, so it can be read without opening the edit page.
The line under the title now shows only the repository. A new test
renders the app page for an app on a non-main branch and checks the
branch is in the title row.

Model: opus-5-5
Co-authored-by: clawbot <sneak+clawbot@sneak.cloud>

.dockerignore

@@ -1,4 +1,5 @@
 .git
+.env
 bin/
 .editorconfig
 .vscode/

README.md

@@ -191,17 +191,24 @@ This ensures the main branch always contains clean, tested, working code.
 
 Environment variables:
 
-| Variable               | Description                                                                                                                                                            | Default                                                  |
-| ---------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------- |
-| `PORT`                 | HTTP listen port                                                                                                                                                       | 8080                                                     |
-| `UPAAS_DATA_DIR`       | Data directory for SQLite and keys                                                                                                                                     | `./data` (local dev only — use absolute path for Docker) |
-| `UPAAS_HOST_DATA_DIR`  | Host path for DATA_DIR (when running in container)                                                                                                                     | _(none — must be set to an absolute path)_               |
-| `UPAAS_DOCKER_HOST`    | Docker socket path                                                                                                                                                     | unix:///var/run/docker.sock                              |
-| `UPAAS_PLAINTEXT_HTTP` | Set when µPaaS is reached over plain HTTP (no TLS-terminating proxy in front) so CSRF origin checks use `http://`. Leave unset behind a TLS-terminating reverse proxy. | false                                                    |
-| `DEBUG`                | Enable debug logging                                                                                                                                                   | false                                                    |
-| `SENTRY_DSN`           | Sentry error reporting DSN                                                                                                                                             | ""                                                       |
-| `METRICS_USERNAME`     | Basic auth for /metrics                                                                                                                                                | ""                                                       |
-| `METRICS_PASSWORD`     | Basic auth for /metrics                                                                                                                                                | ""                                                       |
+| Variable                 | Description                                                                                                                                                                                              | Default                                           |
+| ------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------- |
+| `PORT`                   | HTTP listen port. `UPAAS_PORT` is also read and wins when both are set.                                                                                                                                  | 8080                                              |
+| `UPAAS_DATA_DIR`         | Directory for the SQLite database, session key, builds and deployment logs. Deploys need it to be an absolute path unless `UPAAS_HOST_DATA_DIR` is set.                                                  | `./data` (the Docker image sets `/var/lib/upaas`) |
+| `UPAAS_HOST_DATA_DIR`    | Host path of `UPAAS_DATA_DIR`, needed when upaas runs in a container so the bind mounts it passes to Docker point at the right host directory. When set, it must be absolute, or upaas refuses to start. | the value of `UPAAS_DATA_DIR`                     |
+| `UPAAS_DOCKER_HOST`      | Docker daemon address                                                                                                                                                                                    | unix:///var/run/docker.sock                       |
+| `UPAAS_PLAINTEXT_HTTP`   | Set when µPaaS is reached over plain HTTP (no TLS-terminating proxy in front) so CSRF origin checks use `http://`. Leave unset behind a TLS-terminating reverse proxy.                                   | false                                             |
+| `UPAAS_DEBUG`            | Enable debug logging. Also sends the session cookie without the `Secure` flag.                                                                                                                           | false                                             |
+| `UPAAS_SENTRY_DSN`       | Read but not used: upaas sends nothing to Sentry                                                                                                                                                         | ""                                                |
+| `UPAAS_METRICS_USERNAME` | When set, `/metrics` is served behind basic auth with this username. When unset, there is no `/metrics`.                                                                                                 | ""                                                |
+| `UPAAS_METRICS_PASSWORD` | Basic auth password for `/metrics`                                                                                                                                                                       | ""                                                |
+| `UPAAS_MAINTENANCE_MODE` | Only shown as `maintenanceMode` in the `/health` response; it blocks nothing                                                                                                                             | false                                             |
+| `UPAAS_SESSION_SECRET`   | Key that signs the session and CSRF cookies. When unset, a random key is generated once and kept in `$UPAAS_DATA_DIR/session.key`.                                                                       | ""                                                |
+| `UPAAS_CORS_ORIGINS`     | Comma-separated origins allowed to make cross-origin requests with cookies. When unset, no CORS headers are sent.                                                                                        | ""                                                |
+
+The Docker client also reads the standard `DOCKER_API_VERSION`,
+`DOCKER_CERT_PATH` and `DOCKER_TLS_VERIFY` variables; `UPAAS_DOCKER_HOST`, which
+has a default, always overrides `DOCKER_HOST`.
 
 ## Running with Docker
 
@@ -219,39 +226,31 @@ This recipe serves plain HTTP, so `UPAAS_PLAINTEXT_HTTP=true` is required for
 setup and every other form to pass the CSRF origin check. Behind a
 TLS-terminating reverse proxy, drop that line.
 
-### Docker Compose
+### Deploying with Docker Compose
 
-```yaml
-services:
-    upaas:
-        build: .
-        restart: unless-stopped
-        ports:
-            - "8080:8080"
-        volumes:
-            - /var/run/docker.sock:/var/run/docker.sock
-            - ${HOST_DATA_DIR}:/var/lib/upaas
-        environment:
-            - UPAAS_HOST_DATA_DIR=${HOST_DATA_DIR}
-            # Set when serving plain HTTP (no TLS-terminating proxy); drop behind one
-            - UPAAS_PLAINTEXT_HTTP=true
-            # Optional: uncomment to enable debug logging
-            # - DEBUG=true
-            # Optional: Sentry error reporting
-            # - SENTRY_DSN=https://...
-            # Optional: Prometheus metrics auth
-            # - METRICS_USERNAME=prometheus
-            # - METRICS_PASSWORD=secret
+[`docker-compose.yml`](docker-compose.yml) builds the image from this repo and
+runs it with the Docker socket and the data directory mounted. It reads its
+settings from a `.env` file next to it, which needs at least:
+
+```bash
+HOST_DATA_DIR=/srv/upaas/data
 ```
 
-**Important**: You **must** set `HOST_DATA_DIR` to an **absolute path** on the
-host before running `docker compose up`. This value is bind-mounted into the
-container and passed as `UPAAS_HOST_DATA_DIR` so that Docker bind mounts during
-builds resolve correctly. Relative paths (e.g. `./data`) will break container
-builds because the Docker daemon resolves paths relative to the host, not the
-container.
+Other settings from [Configuration](#configuration) go in the same file, except
+`PORT`, `UPAAS_PORT` and `UPAAS_DATA_DIR`: the compose file sets both port
+settings to 8080 and `UPAAS_DATA_DIR` to `/var/lib/upaas`, overriding `.env`, to
+match its port mapping, healthcheck and data directory mount. Then run
+`docker compose up -d` from the repo root; `docker compose ps` shows the
+container as healthy once `/health` answers.
 
-Example: `HOST_DATA_DIR=/srv/upaas/data docker compose up -d`
+**Important**: `HOST_DATA_DIR` **must** be an **absolute path** on the host. It
+is bind-mounted into the container and passed as `UPAAS_HOST_DATA_DIR` so that
+Docker bind mounts during builds resolve correctly, because the Docker daemon
+resolves paths on the host, not in the container. upaas refuses to start when
+`UPAAS_HOST_DATA_DIR` is a relative path such as `./data`.
+
+The port is published on `127.0.0.1:8080` only, for a TLS-terminating reverse
+proxy in front of it. Leave `UPAAS_PLAINTEXT_HTTP` unset behind that proxy.
 
 Apps are built with BuildKit, so the stages of a multi-stage build are kept in
 Docker's build cache rather than as untagged images. Docker Engine 28.2 and

TODO.md

@@ -20,6 +20,35 @@ regress.
 
 # Completed Steps
 
+- 2026-09-29: The app page shows the app's branch as a label in its title, next
+  to the status badge, instead of after the repository under it (#240).
+
+- 2026-09-29: An app's deployments page now lists only its 10 most recent
+  deployments, newest first, instead of 50 (#238).
+
+- 2026-09-29: `docker-compose.yml` now sets `UPAAS_PORT` to 8080 as well as
+  `PORT`, since upaas reads `UPAAS_PORT` first and a `UPAAS_PORT` in `.env` made
+  it listen away from the port mapping and healthcheck; the README's Compose
+  section names both (#230).
+
+- 2026-09-29: The README Configuration table now lists every setting upaas
+  reads, adding `UPAAS_MAINTENANCE_MODE`, `UPAAS_SESSION_SECRET` and
+  `UPAAS_CORS_ORIGINS`, and gives the real default and effect of each:
+  `UPAAS_PORT` wins over `PORT`, `UPAAS_HOST_DATA_DIR` falls back to
+  `UPAAS_DATA_DIR`, `UPAAS_DEBUG` drops the session cookie's `Secure` flag, and
+  `UPAAS_SENTRY_DSN` is not used (#229).
+
+- 2026-09-28: The README Configuration table now names `UPAAS_DEBUG`,
+  `UPAAS_SENTRY_DSN`, `UPAAS_METRICS_USERNAME` and `UPAAS_METRICS_PASSWORD`, the
+  names upaas actually reads (the unprefixed names it listed were ignored), and
+  the `UPAAS_HOST_DATA_DIR` row refers to `UPAAS_DATA_DIR` (#224).
+
+- 2026-09-28: Added `docker-compose.yml` for deploying upaas: settings from
+  `.env`, the port published on `127.0.0.1` only for a TLS proxy in front, and a
+  healthcheck against `/health`; the README's plain-HTTP Compose example is
+  replaced by a short deploy section. upaas now refuses to start when
+  `UPAAS_HOST_DATA_DIR` is set to a relative path (#223).
+
 - 2026-09-23: Apps are now built with BuildKit, so the stages of a multi-stage
   build stay in Docker's size-limited build cache instead of piling up as
   untagged images; build progress is still written to the deployment log as

docker-compose.yml

@@ -0,0 +1,32 @@
+# Runs upaas. Put settings in .env next to this file; see "Deploying with
+# Docker Compose" in README.md.
+services:
+  upaas:
+    build: .
+    restart: unless-stopped
+    # Every line of .env is passed to upaas as an environment variable.
+    env_file: .env
+    environment:
+      # Override any PORT or UPAAS_PORT in .env, so upaas listens where the
+      # port mapping and healthcheck below expect it. Both are set because
+      # upaas reads UPAAS_PORT first.
+      PORT: "8080"
+      UPAAS_PORT: "8080"
+      # Overrides any UPAAS_DATA_DIR in .env, so the database stays on the
+      # HOST_DATA_DIR mount below instead of inside the container.
+      UPAAS_DATA_DIR: /var/lib/upaas
+      # The Docker daemon resolves app bind mounts on the host, so upaas must
+      # know the host path of its data directory.
+      UPAAS_HOST_DATA_DIR: ${HOST_DATA_DIR:?set HOST_DATA_DIR in .env to an absolute host path}
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      - ${HOST_DATA_DIR:?set HOST_DATA_DIR in .env to an absolute host path}:/var/lib/upaas
+    # Loopback only, for a TLS-terminating reverse proxy in front. Leave
+    # UPAAS_PLAINTEXT_HTTP unset behind that proxy.
+    ports:
+      - "127.0.0.1:8080:8080"
+    healthcheck:
+      test: ["CMD", "wget", "-q", "-O", "/dev/null", "http://127.0.0.1:8080/health"]
+      interval: 30s
+      timeout: 5s
+      retries: 3

internal/config/config.go

@@ -32,6 +32,12 @@ const (
 	filePermissions = 0o600
 )
 
+// errHostDataDirNotAbsolute is returned when UPAAS_HOST_DATA_DIR is set to a
+// relative path, which the Docker daemon cannot resolve for app bind mounts.
+var errHostDataDirNotAbsolute = errors.New(
+	"UPAAS_HOST_DATA_DIR must be an absolute path",
+)
+
 // Params contains dependencies for Config.
 type Params struct {
 	fx.In
@@ -124,6 +130,10 @@ func buildConfig(log *slog.Logger, params *Params) (*Config, error) {
 	dataDir := viper.GetString("DATA_DIR")
 	hostDataDir := viper.GetString("HOST_DATA_DIR")
 
+	if hostDataDir != "" && !filepath.IsAbs(hostDataDir) {
+		return nil, fmt.Errorf("%w, got %q", errHostDataDirNotAbsolute, hostDataDir)
+	}
+
 	if hostDataDir == "" {
 		hostDataDir = dataDir
 	}

internal/config/config_test.go

@@ -0,0 +1,33 @@
+package config //nolint:testpackage // tests unexported buildConfig
+
+import (
+	"errors"
+	"log/slog"
+	"testing"
+)
+
+func TestBuildConfigRejectsRelativeHostDataDir(t *testing.T) {
+	t.Setenv("UPAAS_HOST_DATA_DIR", "./data")
+	setupViper("upaas")
+
+	_, err := buildConfig(slog.Default(), &Params{})
+	if !errors.Is(err, errHostDataDirNotAbsolute) {
+		t.Fatalf("expected errHostDataDirNotAbsolute, got %v", err)
+	}
+}
+
+func TestBuildConfigHostDataDirDefaultsToDataDir(t *testing.T) {
+	t.Setenv("UPAAS_DATA_DIR", "./data")
+	t.Setenv("UPAAS_HOST_DATA_DIR", "")
+	t.Setenv("UPAAS_SESSION_SECRET", "test-secret")
+	setupViper("upaas")
+
+	cfg, err := buildConfig(slog.Default(), &Params{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if cfg.HostDataDir != "./data" {
+		t.Errorf("expected HostDataDir ./data, got %q", cfg.HostDataDir)
+	}
+}

internal/handlers/app.go

@@ -28,7 +28,7 @@ const (
 	// recentDeploymentsLimit is the number of recent deployments to show.
 	recentDeploymentsLimit = 5
 	// deploymentsHistoryLimit is the number of deployments to show in history.
-	deploymentsHistoryLimit = 50
+	deploymentsHistoryLimit = 10
 )
 
 // redirectToApp issues a SeeOther redirect to the page for the given

internal/handlers/app_branch_test.go

@@ -0,0 +1,46 @@
+package handlers_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"sneak.berlin/go/upaas/internal/service/app"
+)
+
+// TestAppPageTitleShowsBranch checks that an app's branch can be read from
+// the app page title, next to the status badge, without opening the edit page.
+func TestAppPageTitleShowsBranch(t *testing.T) {
+	t.Parallel()
+
+	testCtx := setupTestHandlers(t)
+
+	createdApp, err := testCtx.appSvc.CreateApp(t.Context(), app.CreateAppInput{
+		Name:    "branch-shown-app",
+		RepoURL: "git@example.com:user/branch-shown-app.git",
+		Branch:  "staging",
+	})
+	require.NoError(t, err)
+
+	request := httptest.NewRequestWithContext(
+		t.Context(), http.MethodGet, "/apps/"+createdApp.ID, nil,
+	)
+	request = addChiURLParams(request, map[string]string{"id": createdApp.ID})
+	recorder := httptest.NewRecorder()
+
+	testCtx.handlers.HandleAppDetail().ServeHTTP(recorder, request)
+
+	require.Equal(t, http.StatusOK, recorder.Code)
+
+	// The title row runs from the app name heading to the end of its div.
+	_, afterHeading, found := strings.Cut(recorder.Body.String(), "<h1")
+	require.True(t, found, "app page has no heading")
+
+	titleRow, _, _ := strings.Cut(afterHeading, "</div>")
+	assert.Contains(t, titleRow, `x-text="statusLabel"`)
+	assert.Contains(t, titleRow, ">staging</span>")
+}

internal/handlers/handlers_test.go

@@ -8,6 +8,7 @@ import (
 	"strconv"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/stretchr/testify/assert"
@@ -1148,6 +1149,73 @@ func TestHandleCancelDeployReturns404ForUnknownApp(t *testing.T) {
 	assert.Equal(t, http.StatusNotFound, recorder.Code)
 }
 
+// TestHandleAppDeploymentsShowsTenNewest verifies the deployments page
+// lists only the 10 most recent deployments, newest first.
+func TestHandleAppDeploymentsShowsTenNewest(t *testing.T) {
+	t.Parallel()
+
+	testCtx := setupTestHandlers(t)
+	createdApp := createTestApp(t, testCtx, "deployments-page-app")
+
+	// Create 12 deployments, each started one minute after the one before.
+	firstStart := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
+
+	ids := make([]int64, 0, 12)
+
+	for idx := range 12 {
+		deployment := models.NewDeployment(testCtx.database)
+		deployment.AppID = createdApp.ID
+		deployment.Status = models.DeploymentStatusSuccess
+		require.NoError(t, deployment.Save(context.Background()))
+
+		_, err := testCtx.database.Exec(
+			context.Background(),
+			"UPDATE deployments SET started_at = ? WHERE id = ?",
+			firstStart.Add(time.Duration(idx)*time.Minute),
+			deployment.ID,
+		)
+		require.NoError(t, err)
+
+		ids = append(ids, deployment.ID)
+	}
+
+	request := httptest.NewRequestWithContext(
+		t.Context(),
+		http.MethodGet,
+		"/apps/"+createdApp.ID+"/deployments",
+		nil,
+	)
+	request = addChiURLParams(request, map[string]string{"id": createdApp.ID})
+	recorder := httptest.NewRecorder()
+
+	handler := testCtx.handlers.HandleAppDeployments()
+	handler.ServeHTTP(recorder, request)
+
+	require.Equal(t, http.StatusOK, recorder.Code)
+
+	body := recorder.Body.String()
+	card := func(id int64) string {
+		return `data-deployment-id="` + strconv.FormatInt(id, 10) + `"`
+	}
+
+	assert.Equal(t, 10, strings.Count(body, `data-deployment-id="`))
+
+	// The two oldest are left out.
+	assert.NotContains(t, body, card(ids[0]))
+	assert.NotContains(t, body, card(ids[1]))
+
+	// The ten newest are shown, newest first.
+	previous := -1
+
+	for idx := len(ids) - 1; idx >= 2; idx-- {
+		position := strings.Index(body, card(ids[idx]))
+		require.Greater(t, position, previous,
+			"deployment %d missing or out of order", ids[idx])
+
+		previous = position
+	}
+}
+
 func TestHandleWebhookReturns404ForUnknownSecret(t *testing.T) {
 	t.Parallel()
 

templates/app_detail.html

@@ -26,11 +26,12 @@
     <!-- Header -->
     <div class="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-4 mb-8">
         <div>
-            <div class="flex items-center gap-3">
+            <div class="flex flex-wrap items-center gap-3">
                 <h1 class="text-2xl font-medium text-gray-900">{{.App.Name}}</h1>
                 <span x-bind:class="statusBadgeClass" x-text="statusLabel"></span>
+                <span class="badge-neutral font-mono break-all" title="Branch">{{.App.Branch}}</span>
             </div>
-            <p class="text-gray-500 font-mono text-sm mt-1">{{.App.RepoURL}}@{{.App.Branch}}</p>
+            <p class="text-gray-500 font-mono text-sm mt-1">{{.App.RepoURL}}</p>
         </div>
         <div class="flex gap-3">
             <a href="/apps/{{.App.ID}}/edit" class="btn-secondary">Edit</a>