feat(web): weekly automatic updates with health check and rollback (#581)

* feat(web): weekly automatic updates with health check and rollback

A General-tab toggle (off by default) checks for and installs LEDMatrix and
plugin updates once a week, overnight in the configured timezone.

- Pre-update checks skip (and report) instead of forcing: local edits or
  commits, merge/live rebase, no upstream, low disk, missing health check, or
  a version that was already rolled back. An abandoned rebase (HEAD back on a
  branch) is cleared, since it would otherwise block every pull.
- The pull reuses the Update Code path (now perform_core_update(), which
  reports dependency install failures as data).
- ledmatrix-update-verify.service, started via a .path unit from a request
  file, restarts the services from its own cgroup, requires them to come up
  and stay up, and otherwise resets to the previous commit and reinstalls the
  previous requirements. It runs a copy of the checker taken before the pull.
- No SSH needed: switching the toggle on restarts the display service, which
  (as root) installs the two units from the repo templates for the web user.
  first_time_install.sh installs them too and takes --enable-auto-update /
  LEDMATRIX_AUTO_UPDATE (passed through by one-shot-install.sh).
- Plugins update after the code passes its check; failures, blocks and
  rollbacks raise an Overview banner and show under the toggle.

Tested end to end on a Pi: web-UI setup, a good update, a broken web service
and a broken display (both rolled back), a blocked local edit, and an
abandoned rebase found on the device.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* chore(auto-update): address static-analysis findings

- Replace the subprocess.CompletedProcess the verifier fabricated for a
  command that could not start with a plain namedtuple; nothing is executed
  there, but the scanner flags any CompletedProcess built from variables.
- Mark the subprocess imports with the repo's standard B404 annotation (all
  calls are list-form argv, no shell).
- Mark the rollback-failed message as not SQL (B608 matched its wording).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(auto-update): CI failures on Linux

- Keep the setup result when chown fails. CI runs as a non-root user, where
  chown to the web user raises; that discarded the result file, so the
  General tab would never learn whether setup worked. Regression test added.
- Register the two new /api/v3/system/auto-update routes in the URL map
  snapshot.
- Use utility classes app.css defines (space-y-1, hover:text-red-600).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(auto-update): address review feedback

- Health check: a failed restart command no longer lets the check run
  against the still-running old process; it counts as a failure (and after a
  rollback, as a failed rollback). An unreadable restart count is never
  treated as stable, since a crash loop looks healthy between attempts.
- Installer writes the auto_update setting to a temp file and swaps it in,
  keeping mode and owner, so a running config watcher never reads a
  truncated config.json.
- Verify unit quotes its command-line paths (install folders with spaces);
  setup refuses folder names systemd would reinterpret (%, quotes,
  backslashes, control characters) and says so on the General tab.
- The auto-update status route no longer returns exception text.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(auto-update): keep error detail in the status route's 500

test_web_error_detail requires every 5xx handler to log the traceback and
return describe_exception(e), which redacts credentials, so failures are
diagnosable from the web UI. Dropping it for CodeQL broke that policy.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(auto-update): dismiss route rejects non-object JSON with 400

A JSON array or scalar body made `.get('alert_id')` raise, returning 500.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(auto-update): let the app-wide handler answer status-route errors

CodeQL (py/stack-trace-exposure, #709) flagged the route's own except,
which returned describe_exception(e). web_interface/app.py's error handler
already logs the traceback and returns the same redacted detail for any
unhandled exception, so the local copy is removed: same response, no new
exception-to-response flow, and test_web_error_detail's policy still holds.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

scripts/install/install_service.sh

@@ -95,6 +95,19 @@ else
     exit 1
 fi
 
+# Health check / rollback units for automatic updates; see install_web_service.sh.
+for VERIFY_UNIT in ledmatrix-update-verify.service ledmatrix-update-verify.path; do
+    if [ -f "$PROJECT_ROOT_DIR/systemd/$VERIFY_UNIT" ]; then
+        VERIFY_UNIT_TMP=$(mktemp)
+        if sed "s|__PROJECT_ROOT_DIR__|$ESCAPED_PROJECT_ROOT_DIR|g; s|__USER__|$ESCAPED_ACTUAL_USER|g" "$PROJECT_ROOT_DIR/systemd/$VERIFY_UNIT" > "$VERIFY_UNIT_TMP"; then
+            sudo cp "$VERIFY_UNIT_TMP" "/etc/systemd/system/$VERIFY_UNIT"
+        else
+            echo "WARNING: failed to render $VERIFY_UNIT; automatic code updates will stay paused." >&2
+        fi
+        rm -f "$VERIFY_UNIT_TMP"
+    fi
+done
+
 echo "Reloading systemd daemon for web service..."
 sudo systemctl daemon-reload
 
@@ -102,6 +115,11 @@ if [ -f "/etc/systemd/system/ledmatrix-web.service" ]; then
     echo "Enabling ledmatrix-web.service to start on boot..."
     sudo systemctl enable ledmatrix-web.service
 
+    if [ -f /etc/systemd/system/ledmatrix-update-verify.path ]; then
+        echo "Enabling ledmatrix-update-verify.path (automatic update health check)..."
+        sudo systemctl enable --now ledmatrix-update-verify.path || echo "WARNING: could not enable ledmatrix-update-verify.path; automatic code updates will stay paused" >&2
+    fi
+
     echo "Starting ledmatrix-web.service..."
     sudo systemctl start ledmatrix-web.service
 

scripts/install/install_web_service.sh

@@ -46,6 +46,22 @@ ESCAPED_ACTUAL_USER=$(sed_escape_replacement "$ACTUAL_USER")
 sed "s|__PROJECT_ROOT_DIR__|$ESCAPED_PROJECT_ROOT_DIR|g; s|__USER__|$ESCAPED_ACTUAL_USER|g" \
     "$TEMPLATE" > /etc/systemd/system/ledmatrix-web.service
 
+# Health check and rollback for the web UI's automatic updates. Its own unit so
+# it survives the web service restart it performs; never enabled -- the web
+# interface starts it after an update. Without it, automatic code updates
+# stay paused rather than running with nothing to undo them.
+for VERIFY_UNIT in ledmatrix-update-verify.service ledmatrix-update-verify.path; do
+    VERIFY_TEMPLATE="$PROJECT_ROOT_DIR/systemd/$VERIFY_UNIT"
+    if [ -f "$VERIFY_TEMPLATE" ]; then
+        echo "Writing unit file to /etc/systemd/system/$VERIFY_UNIT"
+        sed "s|__PROJECT_ROOT_DIR__|$ESCAPED_PROJECT_ROOT_DIR|g; s|__USER__|$ESCAPED_ACTUAL_USER|g" \
+            "$VERIFY_TEMPLATE" > "/etc/systemd/system/$VERIFY_UNIT"
+        chmod 644 "/etc/systemd/system/$VERIFY_UNIT"
+    else
+        echo "WARNING: $VERIFY_TEMPLATE not found; automatic code updates will stay paused"
+    fi
+done
+
 # Ensure cache directory exists with proper permissions
 # This is a fallback for older systemd versions that don't support CacheDirectory
 # Systemd 239+ will automatically create it via CacheDirectory directive
@@ -80,6 +96,13 @@ systemctl daemon-reload
 echo "Enabling ledmatrix-web.service..."
 systemctl enable ledmatrix-web.service
 
+# The path unit is what starts the health check after an automatic update.
+if [ -f /etc/systemd/system/ledmatrix-update-verify.path ]; then
+    echo "Enabling ledmatrix-update-verify.path..."
+    systemctl enable --now ledmatrix-update-verify.path || \
+        echo "WARNING: could not enable ledmatrix-update-verify.path; automatic code updates will stay paused"
+fi
+
 # Start the service
 echo "Starting ledmatrix-web.service..."
 systemctl start ledmatrix-web.service

scripts/install/one-shot-install.sh

@@ -408,6 +408,7 @@ main() {
         # which would silently reinstate the duplicate apt update.
         sudo -E env TMPDIR=/tmp LEDMATRIX_ASSUME_YES=1 \
             LEDMATRIX_APT_UPDATED="${LEDMATRIX_APT_UPDATED:-0}" \
+            LEDMATRIX_AUTO_UPDATE="${LEDMATRIX_AUTO_UPDATE:-}" \
             bash ./first_time_install.sh -y </dev/null
     fi
     INSTALL_EXIT_CODE=$?