feat(sandbox): add read-only support for local sandbox path mappings (#1808)

backend/packages/harness/deerflow/sandbox/tools.py

@@ -119,6 +119,54 @@ def _is_acp_workspace_path(path: str) -> bool:
     return path == _ACP_WORKSPACE_VIRTUAL_PATH or path.startswith(f"{_ACP_WORKSPACE_VIRTUAL_PATH}/")
 
 
+def _get_custom_mounts():
+    """Get custom volume mounts from sandbox config.
+
+    Result is cached after the first successful config load.  If config loading
+    fails an empty list is returned *without* caching so that a later call can
+    pick up the real value once the config is available.
+    """
+    cached = getattr(_get_custom_mounts, "_cached", None)
+    if cached is not None:
+        return cached
+    try:
+        from pathlib import Path
+
+        from deerflow.config import get_app_config
+
+        config = get_app_config()
+        mounts = []
+        if config.sandbox and config.sandbox.mounts:
+            # Only include mounts whose host_path exists, consistent with
+            # LocalSandboxProvider._setup_path_mappings() which also filters
+            # by host_path.exists().
+            mounts = [m for m in config.sandbox.mounts if Path(m.host_path).exists()]
+        _get_custom_mounts._cached = mounts  # type: ignore[attr-defined]
+        return mounts
+    except Exception:
+        # If config loading fails, return an empty list without caching so that
+        # a later call can retry once the config is available.
+        return []
+
+
+def _is_custom_mount_path(path: str) -> bool:
+    """Check if path is under a custom mount container_path."""
+    for mount in _get_custom_mounts():
+        if path == mount.container_path or path.startswith(f"{mount.container_path}/"):
+            return True
+    return False
+
+
+def _get_custom_mount_for_path(path: str):
+    """Get the mount config matching this path (longest prefix first)."""
+    best = None
+    for mount in _get_custom_mounts():
+        if path == mount.container_path or path.startswith(f"{mount.container_path}/"):
+            if best is None or len(mount.container_path) > len(best.container_path):
+                best = mount
+    return best
+
+
 def _extract_thread_id_from_thread_data(thread_data: "ThreadDataState | None") -> str | None:
     """Extract thread_id from thread_data by inspecting workspace_path.
 
@@ -448,6 +496,8 @@ def mask_local_paths_in_output(output: str, thread_data: ThreadDataState | None)
 
             result = pattern.sub(replace_acp, result)
 
+    # Custom mount host paths are masked by LocalSandbox._reverse_resolve_paths_in_output()
+
     # Mask user-data host paths
     if thread_data is None:
         return result
@@ -496,6 +546,7 @@ def validate_local_tool_path(path: str, thread_data: ThreadDataState | None, *,
       - ``/mnt/user-data/*``  — always allowed (read + write)
       - ``/mnt/skills/*``     — allowed only when *read_only* is True
       - ``/mnt/acp-workspace/*`` — allowed only when *read_only* is True
+      - Custom mount paths (from config.yaml) — respects per-mount ``read_only`` flag
 
     Args:
         path: The virtual path to validate.
@@ -527,7 +578,14 @@ def validate_local_tool_path(path: str, thread_data: ThreadDataState | None, *,
     if path.startswith(f"{VIRTUAL_PATH_PREFIX}/"):
         return
 
-    raise PermissionError(f"Only paths under {VIRTUAL_PATH_PREFIX}/, {_get_skills_container_path()}/, or {_ACP_WORKSPACE_VIRTUAL_PATH}/ are allowed")
+    # Custom mount paths — respect read_only config
+    if _is_custom_mount_path(path):
+        mount = _get_custom_mount_for_path(path)
+        if mount and mount.read_only and not read_only:
+            raise PermissionError(f"Write access to read-only mount is not allowed: {path}")
+        return
+
+    raise PermissionError(f"Only paths under {VIRTUAL_PATH_PREFIX}/, {_get_skills_container_path()}/, {_ACP_WORKSPACE_VIRTUAL_PATH}/, or configured mount paths are allowed")
 
 
 def _validate_resolved_user_data_path(resolved: Path, thread_data: ThreadDataState) -> None:
@@ -577,9 +635,10 @@ def validate_local_bash_command_paths(command: str, thread_data: ThreadDataState
     boundary and must not be treated as isolation from the host filesystem.
 
     In local mode, commands must use virtual paths under /mnt/user-data for
-    user data access. Skills paths under /mnt/skills and ACP workspace paths
-    under /mnt/acp-workspace are allowed (path-traversal checks only; write
-    prevention for bash commands is not enforced here).
+    user data access. Skills paths under /mnt/skills, ACP workspace paths
+    under /mnt/acp-workspace, and custom mount container paths (configured in
+    config.yaml) are allowed (path-traversal checks only; write prevention
+    for bash commands is not enforced here).
     A small allowlist of common system path prefixes is kept for executable
     and device references (e.g. /bin/sh, /dev/null).
     """
@@ -614,6 +673,11 @@ def validate_local_bash_command_paths(command: str, thread_data: ThreadDataState
             _reject_path_traversal(absolute_path)
             continue
 
+        # Allow custom mount container paths
+        if _is_custom_mount_path(absolute_path):
+            _reject_path_traversal(absolute_path)
+            continue
+
         if any(absolute_path == prefix.rstrip("/") or absolute_path.startswith(prefix) for prefix in _LOCAL_BASH_SYSTEM_PATH_PREFIXES):
             continue
 
@@ -658,6 +722,8 @@ def replace_virtual_paths_in_command(command: str, thread_data: ThreadDataState
 
         result = acp_pattern.sub(replace_acp_match, result)
 
+    # Custom mount paths are resolved by LocalSandbox._resolve_paths_in_command()
+
     # Replace user-data paths
     if VIRTUAL_PATH_PREFIX in result and thread_data is not None:
         pattern = re.compile(rf"{re.escape(VIRTUAL_PATH_PREFIX)}(/[^\s\"';&|<>()]*)?")
@@ -954,8 +1020,9 @@ def ls_tool(runtime: ToolRuntime[ContextT, ThreadState], description: str, path:
                 path = _resolve_skills_path(path)
             elif _is_acp_workspace_path(path):
                 path = _resolve_acp_workspace_path(path, _extract_thread_id_from_thread_data(thread_data))
-            else:
+            elif not _is_custom_mount_path(path):
                 path = _resolve_and_validate_user_data_path(path, thread_data)
+            # Custom mount paths are resolved by LocalSandbox._resolve_path()
         children = sandbox.list_dir(path)
         if not children:
             return "(empty)"
@@ -1117,8 +1184,9 @@ def read_file_tool(
                 path = _resolve_skills_path(path)
             elif _is_acp_workspace_path(path):
                 path = _resolve_acp_workspace_path(path, _extract_thread_id_from_thread_data(thread_data))
-            else:
+            elif not _is_custom_mount_path(path):
                 path = _resolve_and_validate_user_data_path(path, thread_data)
+            # Custom mount paths are resolved by LocalSandbox._resolve_path()
         content = sandbox.read_file(path)
         if not content:
             return "(empty)"
@@ -1166,7 +1234,9 @@ def write_file_tool(
         if is_local_sandbox(runtime):
             thread_data = get_thread_data(runtime)
             validate_local_tool_path(path, thread_data)
-            path = _resolve_and_validate_user_data_path(path, thread_data)
+            if not _is_custom_mount_path(path):
+                path = _resolve_and_validate_user_data_path(path, thread_data)
+            # Custom mount paths are resolved by LocalSandbox._resolve_path()
         with get_file_operation_lock(sandbox, path):
             sandbox.write_file(path, content, append)
         return "OK"
@@ -1208,7 +1278,9 @@ def str_replace_tool(
         if is_local_sandbox(runtime):
             thread_data = get_thread_data(runtime)
             validate_local_tool_path(path, thread_data)
-            path = _resolve_and_validate_user_data_path(path, thread_data)
+            if not _is_custom_mount_path(path):
+                path = _resolve_and_validate_user_data_path(path, thread_data)
+            # Custom mount paths are resolved by LocalSandbox._resolve_path()
         with get_file_operation_lock(sandbox, path):
             content = sandbox.read_file(path)
             if not content: