refactor: replace podman-seccomp.json with minimal cap_add, harden bwrap, add sandbox tests

docker-compose.yml

@@ -4,9 +4,13 @@ x-common-config: &common-config
     dockerfile: Dockerfile
   volumes:
     - ~/.nanobot:/home/nanobot/.nanobot
+  cap_drop:
+    - ALL
+  cap_add:
+    - SYS_ADMIN
   security_opt:
     - apparmor=unconfined
-    - seccomp=./podman-seccomp.json
+    - seccomp=unconfined
 
 services:
   nanobot-gateway:

nanobot/agent/tools/sandbox.py

@@ -25,7 +25,7 @@ def _bwrap(command: str, workspace: str, cwd: str) -> str:
     optional  = ["/bin", "/lib", "/lib64", "/etc/alternatives",
                  "/etc/ssl/certs", "/etc/resolv.conf", "/etc/ld.so.cache"]
 
-    args = ["bwrap"]
+    args = ["bwrap", "--new-session", "--die-with-parent"]
     for p in required: args += ["--ro-bind",     p, p]
     for p in optional: args += ["--ro-bind-try", p, p]
     args += [

tests/tools/test_sandbox.py

@@ -0,0 +1,105 @@
+"""Tests for nanobot.agent.tools.sandbox."""
+
+import shlex
+
+import pytest
+
+from nanobot.agent.tools.sandbox import wrap_command
+
+
+def _parse(cmd: str) -> list[str]:
+    """Split a wrapped command back into tokens for assertion."""
+    return shlex.split(cmd)
+
+
+class TestBwrapBackend:
+    def test_basic_structure(self, tmp_path):
+        ws = str(tmp_path / "project")
+        result = wrap_command("bwrap", "echo hi", ws, ws)
+        tokens = _parse(result)
+
+        assert tokens[0] == "bwrap"
+        assert "--new-session" in tokens
+        assert "--die-with-parent" in tokens
+        assert "--ro-bind" in tokens
+        assert "--proc" in tokens
+        assert "--dev" in tokens
+        assert "--tmpfs" in tokens
+
+        sep = tokens.index("--")
+        assert tokens[sep + 1:] == ["sh", "-c", "echo hi"]
+
+    def test_workspace_bind_mounted_rw(self, tmp_path):
+        ws = str(tmp_path / "project")
+        result = wrap_command("bwrap", "ls", ws, ws)
+        tokens = _parse(result)
+
+        bind_idx = [i for i, t in enumerate(tokens) if t == "--bind"]
+        assert any(tokens[i + 1] == ws and tokens[i + 2] == ws for i in bind_idx)
+
+    def test_parent_dir_masked_with_tmpfs(self, tmp_path):
+        ws = tmp_path / "project"
+        result = wrap_command("bwrap", "ls", str(ws), str(ws))
+        tokens = _parse(result)
+
+        tmpfs_indices = [i for i, t in enumerate(tokens) if t == "--tmpfs"]
+        tmpfs_targets = {tokens[i + 1] for i in tmpfs_indices}
+        assert str(ws.parent) in tmpfs_targets
+
+    def test_cwd_inside_workspace(self, tmp_path):
+        ws = tmp_path / "project"
+        sub = ws / "src" / "lib"
+        result = wrap_command("bwrap", "pwd", str(ws), str(sub))
+        tokens = _parse(result)
+
+        chdir_idx = tokens.index("--chdir")
+        assert tokens[chdir_idx + 1] == str(sub)
+
+    def test_cwd_outside_workspace_falls_back(self, tmp_path):
+        ws = tmp_path / "project"
+        outside = tmp_path / "other"
+        result = wrap_command("bwrap", "pwd", str(ws), str(outside))
+        tokens = _parse(result)
+
+        chdir_idx = tokens.index("--chdir")
+        assert tokens[chdir_idx + 1] == str(ws.resolve())
+
+    def test_command_with_special_characters(self, tmp_path):
+        ws = str(tmp_path / "project")
+        cmd = "echo 'hello world' && cat \"file with spaces.txt\""
+        result = wrap_command("bwrap", cmd, ws, ws)
+        tokens = _parse(result)
+
+        sep = tokens.index("--")
+        assert tokens[sep + 1:] == ["sh", "-c", cmd]
+
+    def test_system_dirs_ro_bound(self, tmp_path):
+        ws = str(tmp_path / "project")
+        result = wrap_command("bwrap", "ls", ws, ws)
+        tokens = _parse(result)
+
+        ro_bind_indices = [i for i, t in enumerate(tokens) if t == "--ro-bind"]
+        ro_targets = {tokens[i + 1] for i in ro_bind_indices}
+        assert "/usr" in ro_targets
+
+    def test_optional_dirs_use_ro_bind_try(self, tmp_path):
+        ws = str(tmp_path / "project")
+        result = wrap_command("bwrap", "ls", ws, ws)
+        tokens = _parse(result)
+
+        try_indices = [i for i, t in enumerate(tokens) if t == "--ro-bind-try"]
+        try_targets = {tokens[i + 1] for i in try_indices}
+        assert "/bin" in try_targets
+        assert "/etc/ssl/certs" in try_targets
+
+
+class TestUnknownBackend:
+    def test_raises_value_error(self, tmp_path):
+        ws = str(tmp_path / "project")
+        with pytest.raises(ValueError, match="Unknown sandbox backend"):
+            wrap_command("nonexistent", "ls", ws, ws)
+
+    def test_empty_string_raises(self, tmp_path):
+        ws = str(tmp_path / "project")
+        with pytest.raises(ValueError):
+            wrap_command("", "ls", ws, ws)