Ship the scimesh wheel in releases; wizard and serve install it version-locked

coordinator/internal/agent/setupui/server.go

@@ -176,14 +176,15 @@ func (s *PIDSupervisor) Stop() error {
 
 // Server is the wizard HTTP server, bound to the loopback interface only.
 type Server struct {
-	log         *slog.Logger
-	cfgPath     string
-	logPath     string
-	dir         string
-	sup         Supervisor
-	openBrowser func(string)
-	port        int
-	install     func(ctx context.Context, venvPython, pkg string) error
+	log           *slog.Logger
+	cfgPath       string
+	logPath       string
+	dir           string
+	sup           Supervisor
+	openBrowser   func(string)
+	port          int
+	install       func(ctx context.Context, venvPython, pkg string) error
+	downloadWheel func(ctx context.Context, url, dir string) (string, error)
 }
 
 // Options customises the wizard for tests and embedding.
@@ -196,6 +197,9 @@ type Options struct {
 	// InstallScimesh overrides the pip step of the runtime installer (tests
 	// substitute a fake); nil uses the real pip inside the managed venv.
 	InstallScimesh func(ctx context.Context, venvPython, pkg string) error
+	// DownloadWheel overrides the release-wheel download (tests substitute a
+	// fake); nil downloads from the GitHub release matching the agent version.
+	DownloadWheel func(ctx context.Context, url, dir string) (string, error)
 }
 
 func New(log *slog.Logger, opts Options) *Server {
@@ -223,7 +227,11 @@ func New(log *slog.Logger, opts Options) *Server {
 	if install == nil {
 		install = installScimeshWithPip
 	}
-	return &Server{log: log, cfgPath: cfgPath, logPath: filepath.Join(dir, logFileName), dir: dir, sup: sup, openBrowser: open, port: port, install: install}
+	downloadWheel := opts.DownloadWheel
+	if downloadWheel == nil {
+		downloadWheel = agent.DownloadWheel
+	}
+	return &Server{log: log, cfgPath: cfgPath, logPath: filepath.Join(dir, logFileName), dir: dir, sup: sup, openBrowser: open, port: port, install: install, downloadWheel: downloadWheel}
 }
 
 // Listen binds the loopback listener and returns it; Serve runs the server on
@@ -451,12 +459,24 @@ func (s *Server) handleInstallRuntime(w http.ResponseWriter, r *http.Request) {
 	}
 	if pkg == "" {
 		// No PyPI default on purpose: the PyPI name "scimesh" belongs to an
-		// unrelated project, so a silent `pip install scimesh` would install
-		// the wrong software.
-		writeJSON(w, http.StatusConflict, map[string]string{
-			"error": "no scimesh source configured: set SCIMESH_PIP_PACKAGE to your wheel, checkout or index, then retry",
-		})
-		return
+		// unrelated project. Instead we ship the wheel in our own GitHub
+		// release, version-locked to this binary, and download it from there.
+		url, _, err := agent.ReleaseWheelURL(agent.Version)
+		if err != nil {
+			writeJSON(w, http.StatusConflict, map[string]string{
+				"error": "no scimesh source configured: set SCIMESH_PIP_PACKAGE to your wheel, checkout or index, then retry",
+			})
+			return
+		}
+		local, err := s.downloadWheel(r.Context(), url, s.dir)
+		if err != nil {
+			s.log.Error("download release wheel", "err", err, "url", url)
+			writeJSON(w, http.StatusConflict, map[string]string{
+				"error": "could not download the scimesh wheel for this release: " + err.Error() + ". Set SCIMESH_PIP_PACKAGE to your wheel, checkout or index and retry.",
+			})
+			return
+		}
+		pkg = local
 	}
 
 	python3, err := exec.LookPath("python3")

coordinator/internal/agent/setupui/server_test.go

@@ -29,6 +29,11 @@ func newTestServer(t *testing.T, sup Supervisor) (*Server, string) {
 }
 
 func newTestServerWithInstall(t *testing.T, sup Supervisor, install func(ctx context.Context, venvPython, pkg string) error) (*Server, string) {
+	t.Helper()
+	return newTestServerWithInstallAndWheel(t, sup, install, nil)
+}
+
+func newTestServerWithInstallAndWheel(t *testing.T, sup Supervisor, install func(ctx context.Context, venvPython, pkg string) error, wheel func(ctx context.Context, url, dir string) (string, error)) (*Server, string) {
 	t.Helper()
 	dir := t.TempDir()
 	server := New(testLogger(), Options{
@@ -41,6 +46,7 @@ func newTestServerWithInstall(t *testing.T, sup Supervisor, install func(ctx con
 		Supervisor:     sup,
 		OpenBrowser:    func(string) {},
 		InstallScimesh: install,
+		DownloadWheel:  wheel,
 	})
 	listener, err := server.Listen()
 	if err != nil {
@@ -353,3 +359,53 @@ func TestInstallRuntimeFailureIsExplained(t *testing.T) {
 		t.Errorf("error = %v, want a hint about SCIMESH_PIP_PACKAGE", data["error"])
 	}
 }
+
+func TestInstallRuntimeDownloadsReleaseWheelWhenNoSource(t *testing.T) {
+	oldVersion := agent.Version
+	agent.Version = "1.1.0-alpha.10"
+	t.Cleanup(func() { agent.Version = oldVersion })
+
+	var downloadedURL, installedPkg string
+	sup := &fakeSup{}
+	_, base := newTestServerWithInstallAndWheel(t, sup,
+		func(ctx context.Context, venvPython, pkg string) error {
+			installedPkg = pkg
+			return nil
+		},
+		func(ctx context.Context, url, dir string) (string, error) {
+			downloadedURL = url
+			return filepath.Join(dir, "scimesh-1.1.0a10-py3-none-any.whl"), nil
+		})
+
+	rec, data := postJSON(t, base, "/api/runtime/install", map[string]any{})
+	if rec.Code != http.StatusOK || data["ok"] != true {
+		t.Fatalf("install: got %d %v, want 200 ok", rec.Code, data)
+	}
+	if !strings.Contains(downloadedURL, "releases/download/v1.1.0-alpha.10/scimesh-1.1.0a10-py3-none-any.whl") {
+		t.Errorf("download url = %q, want the release wheel of this version", downloadedURL)
+	}
+	if !strings.HasSuffix(installedPkg, "scimesh-1.1.0a10-py3-none-any.whl") {
+		t.Errorf("pip received %q, want the downloaded wheel", installedPkg)
+	}
+}
+
+func TestInstallRuntimeWheelDownloadFailureIsExplained(t *testing.T) {
+	oldVersion := agent.Version
+	agent.Version = "1.1.0-alpha.10"
+	t.Cleanup(func() { agent.Version = oldVersion })
+
+	sup := &fakeSup{}
+	_, base := newTestServerWithInstallAndWheel(t, sup,
+		func(ctx context.Context, venvPython, pkg string) error { t.Fatal("pip must not run"); return nil },
+		func(ctx context.Context, url, dir string) (string, error) {
+			return "", errors.New("HTTP 404")
+		})
+
+	rec, data := postJSON(t, base, "/api/runtime/install", map[string]any{})
+	if rec.Code != http.StatusConflict {
+		t.Fatalf("got %d, want 409", rec.Code)
+	}
+	if !strings.Contains(data["error"].(string), "SCIMESH_PIP_PACKAGE") {
+		t.Errorf("error = %v, want a SCIMESH_PIP_PACKAGE hint", data["error"])
+	}
+}