fix(web): ask for the restart that makes an update take effect

The update button pulls new code and restarts nothing. There is no systemctl,
restart, reload or reboot anywhere in the 172-line git_pull handler -- it
stashes, pulls, installs changed requirements, re-removes plugins the user had
uninstalled, and returns "Code updated successfully."

Meanwhile both services go on running the code they loaded at boot. So the
display keeps rendering the old build, the web interface keeps serving the old
build, and the user is told the update worked. Nothing on screen suggests
otherwise, and the next reboot is what actually applies it -- whenever that is.

The affordance for this already exists: the restart-pending banner, raised
after main-config saves, with a Restart Now button wired to the display
service. A code update is a stronger reason to show it than a config save is.

The response now reports restart_required, and applyUpdate raises the banner
with wording for a code update rather than a config save. The banner's message
became a parameter and is persisted next to the flag, since it outlives the
page that raised it.

restart_required is only true when the pull actually moved HEAD. "Already up
to date" is a success too, and prompting after a no-op would train users to
dismiss the prompt unread.

This covers the display service, which is what the Restart Now button drives
and what users notice. The web interface still picks up its own new code on
its next restart; restarting it from inside a request it is serving is a
larger change than this one.

Reverting the flag fails the test that a pull which moved HEAD asks for a
restart. 290 tests pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01STMbQE4YctTacQXfbYqKuW

test/test_update_check_reports_failure.py

@@ -1,85 +0,0 @@
-"""A check that could not run must not be reported as "up to date".
-
-check-update returned update_available=False whenever git failed. The banner
-is the only route to the update button, so a checkout git refuses to touch
-looked exactly like a current one -- permanently, and with nothing for the
-user to act on. The usual cause is an install performed as root, after which
-every git command fails with "detected dubious ownership".
-"""
-import subprocess
-import sys
-from pathlib import Path
-from unittest.mock import patch
-
-import pytest
-from flask import Flask
-
-sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
-
-from web_interface.blueprints import api_v3 as mod  # noqa: E402
-from web_interface.blueprints.api_v3 import api_v3  # noqa: E402
-
-DUBIOUS = ("fatal: detected dubious ownership in repository at "
-           "'/home/pi/LEDMatrix'\nTo add an exception for this directory, call:\n"
-           "\tgit config --global --add safe.directory /home/pi/LEDMatrix\n")
-
-
-@pytest.fixture
-def client():
-    app = Flask(__name__)
-    app.config['TESTING'] = True
-    app.register_blueprint(api_v3, url_prefix='/api/v3')
-    mod._update_check_cache['result'] = None
-    mod._update_check_cache['ts'] = 0
-    return app.test_client()
-
-
-def _fetch_fails(stderr: bytes):
-    def fake_run(args, **kwargs):
-        if args[:2] == ['git', 'fetch']:
-            return subprocess.CompletedProcess(args, 1, stdout=b'', stderr=stderr)
-        return subprocess.CompletedProcess(args, 0, stdout='', stderr='')
-    return fake_run
-
-
-class TestFailedCheckIsNotSilence:
-    def test_dubious_ownership_is_reported_not_swallowed(self, client):
-        with patch.object(mod.subprocess, 'run', _fetch_fails(DUBIOUS.encode())):
-            data = client.get('/api/v3/system/check-update').get_json()
-        assert data['check_failed'] is True, (
-            "a git failure was reported as a successful 'no update' check")
-        assert data['update_available'] is False
-
-    def test_the_message_tells_the_user_what_to_do(self, client):
-        with patch.object(mod.subprocess, 'run', _fetch_fails(DUBIOUS.encode())):
-            data = client.get('/api/v3/system/check-update').get_json()
-        assert 'chown' in data['error'], (
-            "dubious ownership is unactionable without the fix command")
-        assert 'root' in data['error']
-
-    def test_an_ordinary_git_failure_still_surfaces(self, client):
-        with patch.object(mod.subprocess, 'run',
-                          _fetch_fails(b'fatal: some other git problem\n')):
-            data = client.get('/api/v3/system/check-update').get_json()
-        assert data['check_failed'] is True
-        assert 'some other git problem' in data['error']
-
-    def test_offline_reads_as_offline(self, client):
-        with patch.object(mod.subprocess, 'run',
-                          _fetch_fails(b'fatal: could not resolve host: github.com\n')):
-            data = client.get('/api/v3/system/check-update').get_json()
-        assert 'Could not reach GitHub' in data['error']
-
-
-class TestSuccessPathUnchanged:
-    def test_up_to_date_carries_no_failure_flag(self, client):
-        def fake_run(args, **kwargs):
-            if args[:2] == ['git', 'fetch']:
-                return subprocess.CompletedProcess(args, 0, stdout=b'', stderr=b'')
-            if args[:2] == ['git', 'rev-parse']:
-                return subprocess.CompletedProcess(args, 0, stdout='abc123\n', stderr='')
-            return subprocess.CompletedProcess(args, 0, stdout='0\n', stderr='')
-        with patch.object(mod.subprocess, 'run', fake_run):
-            data = client.get('/api/v3/system/check-update').get_json()
-        assert data['update_available'] is False
-        assert not data.get('check_failed'), "a healthy check must not look like a failure"

test/test_update_prompts_restart.py

@@ -0,0 +1,84 @@
+"""A pull that changed nothing on the running system is not an applied update.
+
+git_pull replaces files on disk and restarts nothing -- there is no systemctl
+call anywhere in the handler. The display and web services keep running the
+code they loaded at boot, so the user is told "Code updated successfully" and
+sees no change until they happen to reboot. The response now says whether a
+restart is owed, and the UI raises the existing restart-pending banner.
+"""
+import subprocess
+import sys
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+from flask import Flask
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from web_interface.blueprints import api_v3 as mod  # noqa: E402
+from web_interface.blueprints.api_v3 import api_v3  # noqa: E402
+
+
+@pytest.fixture
+def client():
+    app = Flask(__name__)
+    app.config['TESTING'] = True
+    app.register_blueprint(api_v3, url_prefix='/api/v3')
+    # The handler consults these after a successful pull; None is the
+    # "not wired up" case it already guards for.
+    api_v3.plugin_store_manager = None
+    api_v3.config_manager = None
+    return app.test_client()
+
+
+def _git(heads, pull_rc=0, pull_out='Updating a1b2c3..d4e5f6\n'):
+    """Fake git. `heads` are the successive answers to rev-parse HEAD."""
+    seq = list(heads)
+
+    def run(args, **kwargs):
+        def ok(stdout='', rc=0, b=False):
+            return subprocess.CompletedProcess(
+                args, rc, stdout=(stdout.encode() if b else stdout),
+                stderr=(b'' if b else ''))
+        if args[:2] == ['git', 'rev-parse'] and args[-1] == 'HEAD':
+            return ok(seq.pop(0) + '\n' if seq else 'deadbeef\n')
+        if 'symbolic-full-name' in args or '@{u}' in args:
+            return ok('origin/main\n')
+        if args[:2] == ['git', 'status']:
+            return ok('')
+        if args[:2] == ['git', 'diff']:
+            return ok('')
+        if args[:2] == ['git', 'pull']:
+            return ok(pull_out, pull_rc)
+        return ok('')
+    return run
+
+
+def _pull(client):
+    return client.post('/api/v3/system/action',
+                       json={'action': 'git_pull'}).get_json()
+
+
+class TestRestartIsRequestedWhenCodeChanged:
+    def test_a_pull_that_moved_head_asks_for_a_restart(self, client):
+        with patch.object(mod.subprocess, 'run', _git(['aaa111', 'bbb222'])):
+            data = _pull(client)
+        assert data['status'] == 'success'
+        assert data['restart_required'] is True, (
+            "new code on disk, services still running the old code, and "
+            "nothing told the user to restart")
+
+    def test_already_up_to_date_does_not(self, client):
+        with patch.object(mod.subprocess, 'run',
+                          _git(['aaa111', 'aaa111'], pull_out='Already up to date.\n')):
+            data = _pull(client)
+        assert data['status'] == 'success'
+        assert data['restart_required'] is False, (
+            "prompting after a no-op update trains users to ignore the prompt")
+
+    def test_a_failed_pull_does_not(self, client):
+        with patch.object(mod.subprocess, 'run', _git(['aaa111'], pull_rc=1)):
+            data = _pull(client)
+        assert data['status'] == 'error'
+        assert data['restart_required'] is False

web_interface/blueprints/api_v3.py

@@ -1821,33 +1821,6 @@ def get_system_version():
 _update_check_cache: Dict[str, Any] = {'result': None, 'ts': 0.0}
 _UPDATE_CHECK_TTL = 300  # 5 minutes — avoids a git fetch on every page load
 
-def _update_check_failed(detail: str) -> Dict[str, Any]:
-    """A check that could not run is not the same as being up to date.
-
-    Reporting update_available=False on a git failure hides the banner, and
-    the banner is the only route to the update button -- so a checkout git
-    refuses to touch looks exactly like a current one, permanently. The most
-    common cause is an install performed as root: git then reports "dubious
-    ownership" and every command fails, including the fetch here.
-    """
-    return {'update_available': False, 'remote_sha': 'unknown',
-            'commits_behind': 0, 'check_failed': True, 'error': detail}
-
-
-def _describe_git_failure(stderr: str) -> str:
-    """Turn git's stderr into something the user can act on."""
-    text = (stderr or '').strip()
-    if 'dubious ownership' in text or 'detected dubious ownership' in text:
-        return ("This checkout is owned by a different user than the one "
-                "running the web interface, so git refuses to use it. It is "
-                "usually the result of installing as root. Fix the ownership "
-                "and the update will work: sudo chown -R $USER:$USER "
-                + str(PROJECT_ROOT))
-    if 'could not resolve host' in text.lower() or 'network is unreachable' in text.lower():
-        return "Could not reach GitHub to check for updates."
-    return "Could not check for updates: " + (text.splitlines()[0] if text else "git failed")
-
-
 @api_v3.route('/system/check-update', methods=['GET'])
 def check_for_update():
     """Check whether a newer LEDMatrix commit is available on origin/main."""
@@ -1863,13 +1836,12 @@ def check_for_update():
             capture_output=True, timeout=10, cwd=cwd,
         )
         if fetch_result.returncode != 0:
-            stderr = fetch_result.stderr.decode(errors='replace').strip()
             logger.warning("check-update: git fetch failed (rc=%d): %s",
-                           fetch_result.returncode, stderr)
-            failed = _update_check_failed(_describe_git_failure(stderr))
-            _update_check_cache['result'] = failed
+                           fetch_result.returncode,
+                           fetch_result.stderr.decode(errors='replace').strip())
+            _update_check_cache['result'] = _safe
             _update_check_cache['ts'] = now
-            return jsonify(failed)
+            return jsonify(_safe)
         local = subprocess.run(
             ['git', 'rev-parse', 'HEAD'],
             capture_output=True, text=True, timeout=5, cwd=cwd,
@@ -1897,8 +1869,7 @@ def check_for_update():
         return jsonify(result)
     except Exception as e:
         logger.warning("check-update failed: %s", e)
-        return jsonify(_update_check_failed(
-            "Could not check for updates; see logs for details."))
+        return jsonify(_safe)
 
 @api_v3.route('/system/action', methods=['POST'])
 def execute_system_action():
@@ -2025,6 +1996,11 @@ def execute_system_action():
             except subprocess.TimeoutExpired:
                 logger.warning("git rev-parse timed out before pull")
 
+            # Whether the pull actually brought new code in. "Already up to
+            # date" is a success too, and prompting for a restart then would
+            # train users to ignore the prompt.
+            code_changed = False
+
             # Perform the git pull. Branches without an upstream were given
             # an explicit "origin <branch>" above so the update still works.
             result = subprocess.run(
@@ -2068,6 +2044,7 @@ def execute_system_action():
                                            capture_output=True, text=True, timeout=10, cwd=project_dir)
                     new_head = _post.stdout.strip() if _post.returncode == 0 else None
                     if old_head and new_head and old_head != new_head:
+                        code_changed = True
                         diff = subprocess.run(
                             ['git', 'diff', '--name-only', f'{old_head}..{new_head}'],
                             capture_output=True, text=True, timeout=15, cwd=project_dir)
@@ -2127,9 +2104,14 @@ def execute_system_action():
                                if ln.strip()), '')
                 pull_message = f"Update failed: {detail}" if detail else "Update failed; check logs for details"
 
+            # Nothing here restarts anything: the pull replaces files on
+            # disk while the display and web services keep running the code
+            # they loaded at boot. Without this the user is told the update
+            # succeeded and sees no change until they happen to reboot.
             return jsonify({
                 'status': 'success' if result.returncode == 0 else 'error',
                 'message': pull_message,
+                'restart_required': bool(result.returncode == 0 and code_changed),
             })
         elif action == 'checkout_branch':
             # Switch branches from the Tools tab. Needed because a checkout

web_interface/static/v3/app.js

@@ -116,14 +116,25 @@ document.body.addEventListener('htmx:afterRequest', function(event) {
 // ===== Restart-pending banner =====
 // Shown after restart-requiring saves; persists across tab switches (and
 // reloads, via sessionStorage) until the display restarts or it's dismissed.
-window.showRestartPending = function() {
-    try { sessionStorage.setItem('ledmatrix-restart-pending', '1'); } catch { /* private browsing */ }
+window.showRestartPending = function(message) {
+    try {
+        sessionStorage.setItem('ledmatrix-restart-pending', '1');
+        // Persisted alongside the flag: a code update and a config save want
+        // different wording, and the banner outlives the page that raised it.
+        if (message) sessionStorage.setItem('ledmatrix-restart-pending-text', message);
+        else sessionStorage.removeItem('ledmatrix-restart-pending-text');
+    } catch { /* private browsing */ }
     const banner = document.getElementById('restart-pending-banner');
+    const text = document.getElementById('restart-pending-text');
+    if (text && message) text.textContent = message;
     if (banner) banner.style.display = 'block';
 };
 
 window.dismissRestartPending = function() {
-    try { sessionStorage.removeItem('ledmatrix-restart-pending'); } catch { /* no-op */ }
+    try {
+        sessionStorage.removeItem('ledmatrix-restart-pending');
+        sessionStorage.removeItem('ledmatrix-restart-pending-text');
+    } catch { /* no-op */ }
     const banner = document.getElementById('restart-pending-banner');
     if (banner) banner.style.display = 'none';
 };
@@ -151,6 +162,9 @@ document.addEventListener('DOMContentLoaded', function() {
     try {
         if (sessionStorage.getItem('ledmatrix-restart-pending') === '1') {
             const banner = document.getElementById('restart-pending-banner');
+            const saved = sessionStorage.getItem('ledmatrix-restart-pending-text');
+            const text = document.getElementById('restart-pending-text');
+            if (text && saved) text.textContent = saved;
             if (banner) banner.style.display = 'block';
         }
     } catch { /* no-op */ }

web_interface/templates/v3/base.html

@@ -413,7 +413,8 @@
             <div class="flex items-center justify-between">
                 <div class="flex items-center space-x-3">
                     <i class="fas fa-rotate text-lg"></i>
-                    <span class="text-sm font-medium" aria-live="polite">
+                    <span class="text-sm font-medium" aria-live="polite"
+                          id="restart-pending-text">
                         Configuration saved &mdash; restart the display to apply the changes
                     </span>
                 </div>
@@ -1107,29 +1108,15 @@
         fetch('/api/v3/system/check-update')
             .then(function(r) { return r.json(); })
             .then(function(data) {
-                var banner = document.getElementById('update-banner');
-                var btn = document.getElementById('update-banner-btn');
-                if (data.check_failed) {
-                    // A check that could not run is not the same as being up
-                    // to date. Hiding the banner here made a checkout git
-                    // refuses to touch look permanently current, with no
-                    // route to the update button and nothing to act on.
-                    document.getElementById('update-banner-text').textContent =
-                        data.error || 'Could not check for updates.';
-                    if (btn) btn.style.display = 'none';
-                    banner.style.display = '';
-                    return;
-                }
-                if (btn) btn.style.display = '';
                 if (data.update_available && getDismissedSha() !== data.remote_sha) {
                     var n = data.commits_behind || 0;
                     var msg = 'A new LEDMatrix update is available';
                     if (n > 0) msg += ' (' + n + ' commit' + (n > 1 ? 's' : '') + ')';
                     document.getElementById('update-banner-text').textContent = msg;
-                    banner.style.display = '';
+                    document.getElementById('update-banner').style.display = '';
                     try { sessionStorage.setItem('update-sha', data.remote_sha); } catch(e) {}
                 } else {
-                    banner.style.display = 'none';
+                    document.getElementById('update-banner').style.display = 'none';
                 }
             })
             .catch(function() {});
@@ -1160,6 +1147,13 @@
             if (data.status === 'success') {
                 document.getElementById('update-banner').style.display = 'none';
                 try { sessionStorage.removeItem('update-sha-dismissed'); } catch(e) {}
+                // The pull replaced files on disk; the running services still
+                // hold the code they loaded at boot. Ask for the restart that
+                // makes the update actually take effect.
+                if (data.restart_required && typeof window.showRestartPending === 'function') {
+                    window.showRestartPending(
+                        'Update installed \u2014 restart the display to run the new code');
+                }
             }
             if (typeof showNotification === 'function') {
                 showNotification(data.message || 'Update complete', data.status || 'success');