Report the build's own error and refuse daemons too old for BuildKit (closes #234)

A build whose output ends in Docker's error line now fails with that
error, instead of going on to inspect a tag that was never created. The
build output is written to the deployment log before the failure is
recorded, so the log ends in order. Before building, upaas compares the
daemon's API version with 1.39 (Docker Engine 18.09), the first that
builds with BuildKit without experimental mode, and fails the deploy on
an older daemon instead of letting it use the legacy builder. The
README's Compose section gives the update command and the Docker Engine
versions builds need.

Model: opus-5-5

.dockerignore

@@ -1,11 +1,8 @@
-.git
+# .git is sent so that `make build` in the Dockerfile can stamp the commit into
+# upaas. List no tracked file here: git would see it as deleted in the build and
+# the version would end in -dirty.
 .env
 bin/
-.editorconfig
 .vscode/
 .idea/
 *.test
-LICENSE
-CONVENTIONS.md
-REPO_POLICIES.md
-README.md

Dockerfile

@@ -31,6 +31,7 @@ RUN go mod download
 COPY . .
 
 RUN make test
+# Takes the version from `git describe` on the .git copied in above.
 RUN make build
 
 # Runtime stage

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
 
@@ -219,6 +226,10 @@ 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.
 
+The image shows the commit it was built from (the `git describe` output) in the
+page footer, the startup log and `/health`. Build it from a git clone: without
+the `.git` directory it shows `dev`.
+
 ### Deploying with Docker Compose
 
 [`docker-compose.yml`](docker-compose.yml) builds the image from this repo and
@@ -230,10 +241,13 @@ HOST_DATA_DIR=/srv/upaas/data
 ```
 
 Other settings from [Configuration](#configuration) go in the same file, except
-`PORT` and `UPAAS_DATA_DIR`: the compose file sets them to 8080 and
-`/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.
+`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. To update, run `git pull` and then
+`docker compose up -d --build`: without `--build`, Compose keeps running the
+image built from the old checkout.
 
 **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
@@ -249,6 +263,11 @@ Docker's build cache rather than as untagged images. Docker Engine 28.2 and
 later keeps that cache under a size limit by default; on older engines, set
 `"builder": {"gc": {"enabled": true}}` in the host's `daemon.json`.
 
+Building with BuildKit needs Docker Engine 18.09 or later; on an older engine,
+upaas fails the deploy instead of building. A Dockerfile that uses
+`RUN --network` needs Docker Engine 23.0 or later unless its `# syntax=` line
+names Dockerfile frontend 1.3 or later, such as `docker/dockerfile:1`.
+
 Session secrets are automatically generated on first startup and persisted to
 `$UPAAS_DATA_DIR/session.key`.
 

TODO.md

@@ -20,6 +20,42 @@ regress.
 
 # Completed Steps
 
+- 2026-09-29: A failed build now fails the deploy with the build's own error
+  instead of a later "failed to inspect image", and the deployment log shows the
+  end of the build output before that error. upaas refuses to build on a Docker
+  Engine older than 18.09, which cannot build with BuildKit. The README's
+  Compose section says to update with `docker compose up -d --build` and names
+  the Docker Engine versions builds need (#234).
+
+- 2026-09-29: An image built from the `Dockerfile` now shows the commit it was
+  built from (the `git describe` output) in the footer and `/health` instead of
+  `dev`: `.dockerignore` no longer leaves out `.git`, nor any tracked file,
+  which git would count as deleted and mark `-dirty`. upaas now also logs its
+  version at startup; the logger's `Identify()` was never called (#236).
+
+- 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

cmd/upaasd/main.go

@@ -52,6 +52,8 @@ func main() {
 			handlers.New,
 			server.New,
 		),
-		fx.Invoke(func(*server.Server) {}),
+		fx.Invoke(func(log *logger.Logger, _ *server.Server) {
+			log.Identify()
+		}),
 	).Run()
 }

docker-compose.yml

@@ -7,9 +7,11 @@ services:
     # Every line of .env is passed to upaas as an environment variable.
     env_file: .env
     environment:
-      # Overrides any PORT in .env, so upaas listens where the port mapping
-      # and healthcheck below expect it.
+      # 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

internal/docker/client.go

@@ -21,6 +21,7 @@ import (
 	"github.com/docker/docker/api/types/image"
 	"github.com/docker/docker/api/types/mount"
 	"github.com/docker/docker/api/types/network"
+	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/docker/client"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/jsonmessage"
@@ -61,6 +62,15 @@ var ErrInvalidBranch = errors.New("invalid branch name")
 // ErrInvalidCommitSHA is returned when a commit SHA is not a valid hex string.
 var ErrInvalidCommitSHA = errors.New("invalid commit SHA")
 
+// ErrBuildKitUnavailable is returned when the Docker daemon is too old to
+// build with BuildKit.
+var ErrBuildKitUnavailable = errors.New("BuildKit is unavailable on the Docker daemon")
+
+// minBuildKitAPIVersion is the API version of Docker Engine 18.09, the first
+// that builds with BuildKit when asked to without experimental mode. Older
+// daemons refuse the request or silently use the legacy builder.
+const minBuildKitAPIVersion = "1.39"
+
 // validBranchRe matches safe git branch names.
 var validBranchRe = regexp.MustCompile(`^[a-zA-Z0-9._/\-]+$`)
 
@@ -595,6 +605,20 @@ func (c *Client) performBuild(
 	ctx context.Context,
 	opts BuildImageOptions,
 ) (ImageID, error) {
+	server, err := c.docker.ServerVersion(ctx)
+	if err != nil {
+		return "", fmt.Errorf("failed to get Docker version: %w", err)
+	}
+
+	if versions.LessThan(server.APIVersion, minBuildKitAPIVersion) {
+		return "", fmt.Errorf(
+			"%w: Docker Engine %s (API %s) is older than 18.09 (API %s); "+
+				"upgrade Docker Engine",
+			ErrBuildKitUnavailable, server.Version, server.APIVersion,
+			minBuildKitAPIVersion,
+		)
+	}
+
 	// Create tar archive of build context
 	tarArchive, err := archive.TarWithOptions(opts.ContextDir, &archive.TarOptions{})
 	if err != nil {
@@ -660,7 +684,8 @@ const scannerMaxBufferSize = 1024 * 1024 // 1MB
 // newline-delimited JSON. BuildKit's progress arrives encoded in
 // "moby.buildkit.trace" messages; these are decoded and written as plain
 // text, as "docker build --progress=plain" shows it. Other lines, such as
-// build errors, are written unchanged.
+// build errors, are written unchanged. Docker ends a failed build with a line
+// carrying the error; it is returned once the output is written.
 func (c *Client) streamBuildOutput(
 	ctx context.Context,
 	body io.Reader,
@@ -690,6 +715,8 @@ func (c *Client) streamBuildOutput(
 	buf := make([]byte, 0, scannerInitialBufferSize)
 	scanner.Buffer(buf, scannerMaxBufferSize)
 
+	var buildErr error
+
 	for scanner.Scan() {
 		line := scanner.Bytes()
 
@@ -708,6 +735,10 @@ func (c *Client) streamBuildOutput(
 			continue
 		}
 
+		if err == nil && msg.Error != nil {
+			buildErr = msg.Error
+		}
+
 		// One write per line, so it is not split by the display's output.
 		_, _ = fmt.Fprintf(out, "%s\n", line)
 	}
@@ -720,7 +751,7 @@ func (c *Client) streamBuildOutput(
 		return fmt.Errorf("failed to read build output: %w", scanErr)
 	}
 
-	return nil
+	return buildErr
 }
 
 func (c *Client) performClone(

internal/docker/validation_test.go

@@ -271,6 +271,8 @@ func TestPerformBuildUsesBuildKit(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(
 		func(w http.ResponseWriter, r *http.Request) {
 			switch {
+			case strings.HasSuffix(r.URL.Path, "/version"):
+				_, _ = w.Write([]byte(`{"Version":"27.3.1","ApiVersion":"1.47"}`))
 			case strings.HasSuffix(r.URL.Path, "/build"):
 				if r.URL.Query().Get("version") != "2" {
 					http.Error(w, "not a BuildKit build", http.StatusBadRequest)
@@ -314,3 +316,82 @@ func TestPerformBuildUsesBuildKit(t *testing.T) {
 		t.Errorf("build log is missing the build step:\n%s", buildLog.String())
 	}
 }
+
+// TestPerformBuildFails runs builds that fail against a fake Docker API and
+// checks that each returns its own error and that no image is inspected
+// afterwards.
+func TestPerformBuildFails(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name        string
+		engine      string // Docker Engine version the fake daemon reports
+		apiVersion  string // API version the fake daemon reports
+		buildOutput string
+		wantErr     string
+	}{
+		{
+			name:       "build step fails",
+			engine:     "27.3.1",
+			apiVersion: "1.47",
+			buildOutput: `{"stream":"Step 1/1 : RUN false\n"}` + "\n" +
+				`{"errorDetail":{"message":"exit code: 1"},"error":"exit code: 1"}`,
+			wantErr: "exit code: 1",
+		},
+		{
+			name:       "daemon too old for BuildKit",
+			engine:     "18.06.3-ce",
+			apiVersion: "1.38",
+			wantErr: "BuildKit is unavailable on the Docker daemon: " +
+				"Docker Engine 18.06.3-ce (API 1.38) is older than 18.09 (API 1.39); " +
+				"upgrade Docker Engine",
+		},
+		{
+			// The build step's own error shows the build went ahead.
+			name:       "daemon at API 1.39 builds",
+			engine:     "18.09.9",
+			apiVersion: "1.39",
+			buildOutput: `{"stream":"Step 1/1 : RUN false\n"}` + "\n" +
+				`{"errorDetail":{"message":"exit code: 1"},"error":"exit code: 1"}`,
+			wantErr: "exit code: 1",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			srv := httptest.NewServer(http.HandlerFunc(
+				func(w http.ResponseWriter, r *http.Request) {
+					switch {
+					case strings.HasSuffix(r.URL.Path, "/version"):
+						_, _ = fmt.Fprintf(w, `{"Version":%q,"ApiVersion":%q}`,
+							tt.engine, tt.apiVersion)
+					case strings.HasSuffix(r.URL.Path, "/build"):
+						_, _ = w.Write([]byte(tt.buildOutput))
+					default:
+						t.Errorf("unexpected request to %s", r.URL.Path)
+					}
+				},
+			))
+			t.Cleanup(srv.Close)
+
+			dockerAPI, err := client.NewClientWithOpts(
+				client.WithHost("tcp://" + srv.Listener.Addr().String()),
+			)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			c := &Client{docker: dockerAPI, log: slog.Default()}
+
+			_, err = c.performBuild(t.Context(), BuildImageOptions{
+				ContextDir: t.TempDir(),
+				Tags:       []string{"upaas-test:1"},
+			})
+			if err == nil || err.Error() != tt.wantErr {
+				t.Errorf("got error %v, want %q", err, tt.wantErr)
+			}
+		})
+	}
+}

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()
 

internal/service/deploy/deploy.go

@@ -923,7 +923,6 @@ func (svc *Service) buildImage(
 
 	// Create log writer that flushes build output to deployment logs every second
 	logWriter := newDeploymentLogWriter(ctx, deployment)
-	defer logWriter.Close()
 
 	// BuildImage creates a tar archive from the local filesystem,
 	// so it needs the container path where files exist, not the host path.
@@ -933,6 +932,10 @@ func (svc *Service) buildImage(
 		Tags:           []string{imageTag},
 		LogWriter:      logWriter,
 	})
+
+	// Write the rest of the build output to the log before the result.
+	logWriter.Close()
+
 	if err != nil {
 		svc.notify.NotifyBuildFailed(ctx, app, deployment, err)
 		svc.failDeployment(

internal/service/deploy/deploy_build_test.go

@@ -0,0 +1,91 @@
+package deploy_test
+
+import (
+	"context"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/fx/fxtest"
+
+	"sneak.berlin/go/upaas/internal/config"
+	"sneak.berlin/go/upaas/internal/database"
+	"sneak.berlin/go/upaas/internal/docker"
+	"sneak.berlin/go/upaas/internal/logger"
+	"sneak.berlin/go/upaas/internal/models"
+	"sneak.berlin/go/upaas/internal/service/deploy"
+)
+
+// TestBuildImageLogsBuildErrorBeforeDeployError runs a build that fails
+// against a fake Docker API and checks that the deploy fails with the
+// build's own error, which the deployment log shows before the deploy's.
+func TestBuildImageLogsBuildErrorBeforeDeployError(t *testing.T) {
+	t.Parallel()
+
+	srv := httptest.NewServer(http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+
+			switch {
+			case strings.HasSuffix(r.URL.Path, "/containers/create"):
+				_, _ = w.Write([]byte(`{"Id":"gitcontainer"}`))
+			case strings.HasSuffix(r.URL.Path, "/version"):
+				_, _ = w.Write([]byte(`{"Version":"27.3.1","ApiVersion":"1.47"}`))
+			case strings.HasSuffix(r.URL.Path, "/build"):
+				_, _ = w.Write([]byte(`{"stream":"Step 1/1 : RUN false\n"}` + "\n" +
+					`{"errorDetail":{"message":"exit code: 1"},"error":"exit code: 1"}`))
+			default:
+				// The steps of the git clone, which succeeds.
+				_, _ = w.Write([]byte(`{}`))
+			}
+		},
+	))
+	t.Cleanup(srv.Close)
+
+	log := slog.New(slog.NewTextHandler(os.Stderr, nil))
+	lifecycle := fxtest.NewLifecycle(t)
+
+	dockerClient, err := docker.New(lifecycle, docker.Params{
+		Logger: logger.NewForTest(log),
+		Config: &config.Config{DockerHost: "tcp://" + srv.Listener.Addr().String()},
+	})
+	require.NoError(t, err)
+
+	lifecycle.RequireStart()
+	t.Cleanup(lifecycle.RequireStop)
+
+	db := database.NewTestDatabase(t)
+	ctx := context.Background()
+
+	app := models.NewApp(db)
+	app.ID = "buildapp-id"
+	app.Name = "buildapp"
+	app.Branch = "main"
+	require.NoError(t, app.Save(ctx))
+
+	deployment := models.NewDeployment(db)
+	deployment.AppID = app.ID
+	require.NoError(t, deployment.Save(ctx))
+
+	dataDir := t.TempDir()
+	cfg := &config.Config{DataDir: dataDir, HostDataDir: dataDir}
+
+	// The service has no notify service: the app has no ntfy topic and no
+	// Slack webhook, so the build failure notification sends nothing.
+	svc := deploy.NewTestServiceWithConfig(log, cfg, dockerClient)
+
+	_, err = svc.BuildImage(ctx, app, deployment)
+	require.EqualError(t, err, "failed to build image: exit code: 1")
+
+	logs := deployment.Logs.String
+	buildError := strings.Index(logs, "ERROR: exit code: 1")
+	deployError := strings.Index(logs, "ERROR: failed to build image: exit code: 1")
+
+	require.NotEqual(t, -1, buildError, logs)
+	assert.Less(t, buildError, deployError, logs)
+}

internal/service/deploy/export_test.go

@@ -100,6 +100,15 @@ func (svc *Service) RecordDeployedImage(
 	return svc.recordDeployedImage(ctx, app, deployment, imageID)
 }
 
+// BuildImage exposes buildImage for testing.
+func (svc *Service) BuildImage(
+	ctx context.Context,
+	app *models.App,
+	deployment *models.Deployment,
+) (docker.ImageID, error) {
+	return svc.buildImage(ctx, app, deployment)
+}
+
 // BuildContainerOptionsExported exposes buildContainerOptions for testing.
 func (svc *Service) BuildContainerOptionsExported(
 	ctx context.Context,

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>