Initial commit: Metro Warden TUI network operations center

ui/tabs/routes.py

@@ -0,0 +1,185 @@
+"""
+Routes Tab — displays the system routing table.
+
+Reads routes from the OS on mount and on manual refresh.
+Uses ``ip route show`` on Linux or ``netstat -rn`` as a fallback.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import shutil
+import subprocess
+import re
+from typing import List, Dict
+
+from textual.app import ComposeResult
+from textual.binding import Binding
+from textual.widget import Widget
+from textual.widgets import DataTable, Footer, Label, Static
+
+
+def _parse_ip_route() -> List[Dict]:
+    """Parse ``ip route show`` output into a list of route dicts."""
+    routes: List[Dict] = []
+    try:
+        result = subprocess.run(
+            ["ip", "route", "show"],
+            capture_output=True,
+            text=True,
+            timeout=5,
+        )
+        for line in result.stdout.splitlines():
+            line = line.strip()
+            if not line:
+                continue
+            parts = line.split()
+            dest = parts[0] if parts else "?"
+            gateway = ""
+            iface = ""
+            metric = ""
+            proto = ""
+            scope = ""
+            src = ""
+            i = 1
+            while i < len(parts):
+                token = parts[i]
+                if token == "via" and i + 1 < len(parts):
+                    gateway = parts[i + 1]; i += 2
+                elif token == "dev" and i + 1 < len(parts):
+                    iface = parts[i + 1]; i += 2
+                elif token == "metric" and i + 1 < len(parts):
+                    metric = parts[i + 1]; i += 2
+                elif token == "proto" and i + 1 < len(parts):
+                    proto = parts[i + 1]; i += 2
+                elif token == "scope" and i + 1 < len(parts):
+                    scope = parts[i + 1]; i += 2
+                elif token == "src" and i + 1 < len(parts):
+                    src = parts[i + 1]; i += 2
+                else:
+                    i += 1
+            routes.append({
+                "destination": dest,
+                "gateway": gateway or "—",
+                "interface": iface or "—",
+                "metric": metric or "—",
+                "proto": proto or "—",
+                "scope": scope or "—",
+                "src": src or "—",
+            })
+    except (subprocess.TimeoutExpired, FileNotFoundError):
+        pass
+    return routes
+
+
+def _parse_netstat_route() -> List[Dict]:
+    """Fallback: parse ``netstat -rn`` output."""
+    routes: List[Dict] = []
+    try:
+        result = subprocess.run(
+            ["netstat", "-rn"],
+            capture_output=True,
+            text=True,
+            timeout=5,
+        )
+        lines = result.stdout.splitlines()
+        # Skip header lines
+        data_start = False
+        for line in lines:
+            if re.match(r"^(Destination|0\.0\.0\.0|default)", line):
+                data_start = True
+            if not data_start:
+                continue
+            parts = line.split()
+            if len(parts) >= 4:
+                routes.append({
+                    "destination": parts[0],
+                    "gateway": parts[1] if len(parts) > 1 else "—",
+                    "interface": parts[-1],
+                    "metric": "—",
+                    "proto": "—",
+                    "scope": "—",
+                    "src": "—",
+                })
+    except (subprocess.TimeoutExpired, FileNotFoundError):
+        pass
+    return routes
+
+
+def _get_routes() -> List[Dict]:
+    if shutil.which("ip"):
+        routes = _parse_ip_route()
+        if routes:
+            return routes
+    return _parse_netstat_route()
+
+
+class RoutesTab(Widget):
+    """Routing table tab — refreshes on mount and on 'r' keypress."""
+
+    DEFAULT_CSS = """
+    RoutesTab {
+        layout: vertical;
+        height: 1fr;
+        padding: 1 2;
+    }
+    RoutesTab .tab-title {
+        color: $primary;
+        text-style: bold;
+        height: 1;
+        margin-bottom: 1;
+    }
+    RoutesTab DataTable {
+        height: 1fr;
+        border: round $primary;
+    }
+    RoutesTab .hint {
+        height: 1;
+        color: $text-muted;
+        margin-top: 1;
+    }
+    """
+
+    BINDINGS = [Binding("r", "refresh_routes", "Refresh")]
+
+    COLUMNS = [
+        ("Destination", 20),
+        ("Gateway", 16),
+        ("Interface", 12),
+        ("Proto", 8),
+        ("Scope", 8),
+        ("Metric", 8),
+        ("Src", 16),
+    ]
+
+    def compose(self) -> ComposeResult:
+        yield Static("//  ROUTES  —  Routing Table", classes="tab-title")
+        yield DataTable(id="routes-table", zebra_stripes=True, cursor_type="row")
+        yield Static("Press [bold]r[/bold] to refresh", classes="hint")
+
+    def on_mount(self) -> None:
+        table = self.query_one("#routes-table", DataTable)
+        for col_label, width in self.COLUMNS:
+            table.add_column(col_label, width=width)
+        self.run_worker(self._load_routes(), exclusive=True)
+
+    async def _load_routes(self) -> None:
+        routes = await asyncio.to_thread(_get_routes)
+        self._populate_table(routes)
+
+    def _populate_table(self, routes: List[Dict]) -> None:
+        table = self.query_one("#routes-table", DataTable)
+        table.clear()
+        for r in routes:
+            table.add_row(
+                r["destination"],
+                r["gateway"],
+                r["interface"],
+                r["proto"],
+                r["scope"],
+                r["metric"],
+                r["src"],
+            )
+
+    def action_refresh_routes(self) -> None:
+        self.run_worker(self._load_routes(), exclusive=True)