Add a mesh scope to the Streams card

Local stays the default and the cheap path; mesh asks each partner for its own sessions over SSH, live rather than cached, because a stream is true for minutes and a cached one would be confidently wrong about the only thing the card exists to say.
2026-08-21 08:38:37 -04:00
parent 331b7b6b13
commit 81abc5adee
4 changed files with 202 additions and 8 deletions
@@ -258,6 +258,113 @@ function vv_media_sessions(): array {
    ];
 }

+// Who is watching, across the whole mesh.
+//
+// Fetched live rather than read from a cache, unlike vv_media_servers_mesh(). A server's version
+// and CPU are true for hours; a stream is true for minutes, and a "now playing" card assembled
+// from a two-hour-old file would be confidently wrong about the one thing it exists to say. The
+// cost is only paid when the operator asks for the mesh view — the card polls local by default.
+//
+// Each partner answers about itself for the reason the arr and media-server collectors do: its
+// Emby URL is http://localhost:8096, which is true there and meaningless here, and its API keys
+// never leave it. Same transport as remote_arr_cache_writer.sh, at a faster cadence, so the
+// connection is multiplexed and every hop is bounded.
+//
+// A partner that cannot be reached is reported as unreachable, never as zero streams. Those look
+// identical in a total and mean opposite things.
+function vv_media_sessions_mesh(): array {
+    $me    = vv_detect_host();
+    $hosts = function_exists('vv_known_hosts') ? vv_known_hosts() : [$me => $me];
+
+    $nodes    = [];
+    $sessions = [];
+    $names    = [];
+    $count    = 0;
+
+    foreach ($hosts as $h => $hostName) {
+        if ($h === $me) {
+            $local = vv_media_sessions();
+            $nodes[] = ['host' => $h, 'name' => $hostName, 'local' => true, 'reachable' => true,
+                        'server_count' => $local['server_count'], 'stream_count' => count($local['sessions'])];
+            foreach ($local['sessions'] as $s) {
+                $s['_host'] = $h; $s['_hostName'] = $hostName; $s['_local'] = true;
+                $sessions[] = $s;
+            }
+            $names  = array_merge($names, $local['server_names']);
+            $count += $local['server_count'];
+            continue;
+        }
+
+        $remote = vv_media_sessions_remote($h, $hostName);
+        $nodes[] = ['host' => $h, 'name' => $hostName, 'local' => false,
+                    'reachable'    => $remote !== null,
+                    'server_count' => $remote['server_count'] ?? 0,
+                    'stream_count' => $remote !== null ? count($remote['sessions']) : 0];
+        if ($remote === null) continue;
+
+        foreach ($remote['sessions'] as $s) {
+            $s['_host'] = $h; $s['_hostName'] = $hostName; $s['_local'] = false;
+            $sessions[] = $s;
+        }
+        $names  = array_merge($names, $remote['server_names']);
+        $count += $remote['server_count'];
+    }
+
+    return [
+        'scope'        => 'mesh',
+        'nodes'        => $nodes,
+        'sessions'     => $sessions,
+        'server_names' => $names,
+        'server_count' => $count,
+    ];
+}
+
+// One partner's sessions, or null when it could not be asked.
+//
+// Null rather than an empty payload, deliberately: the caller has to be able to distinguish "that
+// node has nobody watching" from "that node did not answer", and an empty array cannot carry the
+// difference.
+function vv_media_sessions_remote(string $host, string $hostName): ?array {
+    $vars   = vv_conf_vars();
+    $sshKey = $vars[strtoupper(vv_detect_host()) . '_SSH_KEY'] ?? '';
+    if (!$sshKey || !is_file($sshKey)) return null;
+
+    $ip = vv_resolve_tailscale_ip($hostName);
+    if (!$ip) return null;
+
+    // The WebGUI symlink, which is where Unraid serves the plugin from on every node whatever its
+    // storage mode — the same path remote_arr_cache_writer.sh uses, and not a guess about where
+    // the partner installed itself.
+    $php = 'php -r ' . escapeshellarg(
+        "require_once '/usr/local/emhttp/plugins/varaverk/include/media.php';"
+        . " echo json_encode(vv_media_sessions());"
+    );
+
+    // ControlPersist because the card polls this every 12 seconds while the mesh view is open, and
+    // a fresh handshake per poll per partner is most of the cost. Timeouts are short: a dark
+    // partner must render as unreachable quickly, not hold the whole card.
+    $sock = rtrim(VV_CACHE_ROOT, '/') . '/ssh';
+    if (!is_dir($sock)) @mkdir($sock, 0700, true);
+
+    $cmd = 'timeout 8 ssh -i ' . escapeshellarg($sshKey)
+         . ' -o BatchMode=yes -o StrictHostKeyChecking=no -o ConnectTimeout=5'
+         . ' -o ControlMaster=auto -o ControlPersist=60s'
+         . ' -o ControlPath=' . escapeshellarg($sock . '/media-%h')
+         . ' root@' . escapeshellarg($ip) . ' ' . escapeshellarg($php) . ' 2>/dev/null';
+
+    $raw = shell_exec($cmd);
+    if (!$raw) return null;
+
+    $d = json_decode(trim($raw), true);
+    if (!is_array($d) || !isset($d['sessions'])) return null;
+
+    return [
+        'sessions'     => is_array($d['sessions']) ? $d['sessions'] : [],
+        'server_names' => is_array($d['server_names'] ?? null) ? $d['server_names'] : [],
+        'server_count' => (int)($d['server_count'] ?? 0),
+    ];
+}
+
 // ── What each media server is actually doing ──────────────────────────────────────────────────
 // Two halves that only mean something together. The application knows its version, whether an
 // update is waiting and who is watching; the container knows what that is costing in CPU, memory