[Core] Add default excludes for working_dir uploads

doc/source/ray-core/handling-dependencies.rst

@@ -507,6 +507,8 @@ The ``runtime_env`` is a Python dictionary or a Python class :class:`ray.runtime
 
   Note: By default, if the local directory contains a ``.gitignore`` and/or ``.rayignore`` file, the specified files are not uploaded to the cluster. To disable the ``.gitignore`` from being considered, set ``RAY_RUNTIME_ENV_IGNORE_GITIGNORE=1`` on the machine doing the uploading.
 
+  Note: By default, common directories (``.git``, ``.venv``, ``venv``, ``__pycache__``) are automatically excluded from the ``working_dir`` upload. You can override these defaults by setting the ``RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES`` environment variable to a comma-separated list of patterns, or set it to an empty string to disable default excludes entirely.
+
   Note: If the local directory contains symbolic links, Ray follows the links and the files they point to are uploaded to the cluster.
 
 - ``py_modules`` (List[str|module]): Specifies Python modules to be available for import in the Ray workers.  (For more ways to specify packages, see also the ``pip`` and ``conda`` fields below.)
@@ -534,7 +536,6 @@ The ``runtime_env`` is a Python dictionary or a Python class :class:`ray.runtime
 
   Note: For option (1), by default, if the local directory contains a ``.gitignore`` and/or ``.rayignore`` file, the specified files are not uploaded to the cluster. To disable the ``.gitignore`` from being considered, set ``RAY_RUNTIME_ENV_IGNORE_GITIGNORE=1`` on the machine doing the uploading.
 
-
 - ``py_executable`` (str): Specifies the executable used for running the Ray workers. It can include arguments as well. The executable can be
   located in the `working_dir`. This runtime environment is useful to run workers in a custom debugger or profiler as well as to run workers
   in an environment set up by a package manager like `UV` (see :ref:`here <use-uv-for-package-management>`).

python/ray/_private/ray_constants.py

@@ -155,6 +155,21 @@ def env_set_by_user(key):
 # If set to 1, then `.gitignore` files will not be parsed and loaded into "excludes"
 # when using a local working_dir or py_modules.
 RAY_RUNTIME_ENV_IGNORE_GITIGNORE = "RAY_RUNTIME_ENV_IGNORE_GITIGNORE"
+# Default directories to exclude when packaging working_dir.
+# Override by setting the RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES
+# (comma-separated) environment variable. Set to an empty string to disable.
+# `.git` is necessary since it is never in .gitignore.
+RAY_RUNTIME_ENV_DEFAULT_EXCLUDES = ".git,.venv,venv,__pycache__"
+
+
+def get_runtime_env_default_excludes() -> list[str]:
+    """Get default excludes for working_dir, overridable via RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES environment variable."""
+    val = os.environ.get(
+        "RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES", RAY_RUNTIME_ENV_DEFAULT_EXCLUDES
+    )
+    return [x.strip() for x in val.split(",") if x.strip()]
+
+
 # Hook for running a user-specified runtime-env hook. This hook will be called
 # unconditionally given the runtime_env dict passed for ray.init. It must return
 # a rewritten runtime_env dict. Example: "your.module.runtime_env_hook".

python/ray/_private/runtime_env/packaging.py

@@ -453,10 +453,10 @@ def _store_package_in_gcs(
     if len(data) >= GCS_STORAGE_MAX_SIZE:
         raise ValueError(
             f"Package size ({size_str}) exceeds the maximum size of "
-            f"{_mib_string(GCS_STORAGE_MAX_SIZE)}. You can exclude large "
-            "files using the 'excludes' option to the runtime_env or provide "
-            "a remote URI of a zip file using protocols such as 's3://', "
-            "'https://' and so on, refer to "
+            f"{_mib_string(GCS_STORAGE_MAX_SIZE)}. To exclude large files, "
+            "add them to '.gitignore' or '.rayignore' files, or "
+            "use the 'excludes' option in the runtime_env, or provide a "
+            "URI of a remote zip file. For more information, refer to "
             "https://docs.ray.io/en/latest/ray-core/handling-dependencies.html#api-reference."  # noqa
         )
 

python/ray/_private/runtime_env/working_dir.py

@@ -22,10 +22,12 @@
 from ray._private.utils import get_directory_size_bytes
 from ray._raylet import GcsClient
 from ray.exceptions import RuntimeEnvSetupError
+from ray.util.debug import log_once
 
 default_logger = logging.getLogger(__name__)
 
 _WIN32 = os.name == "nt"
+_LOG_ONCE_DEFAULT_EXCLUDE_PREFIX = "runtime_env_default_exclude:"
 
 
 def upload_working_dir_if_needed(
@@ -38,6 +40,12 @@ def upload_working_dir_if_needed(
     """Uploads the working_dir and replaces it with a URI.
 
     If the working_dir is already a URI, this is a no-op.
+
+    Excludes are combined from:
+      - .gitignore and .rayignore files in the working_dir
+      - runtime_env["excludes"] field
+      - RAY_RUNTIME_ENV_DEFAULT_EXCLUDES constant, overridable via
+        RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES environment variable
     """
     working_dir = runtime_env.get("working_dir")
     if working_dir is None:
@@ -63,7 +71,25 @@ def upload_working_dir_if_needed(
             raise ValueError("Only .zip files supported for remote URIs.")
         return runtime_env
 
-    excludes = runtime_env.get("excludes", None)
+    default_excludes = ray_constants.get_runtime_env_default_excludes()
+    user_excludes = runtime_env.get("excludes") or []
+    excludes = default_excludes + list(user_excludes)
+    # TODO(ricardo): 2026-01-07 Remove these warnings in a few releases. Added in
+    # case users rely on these directories being uploaded with their working_dir
+    # since this change would be difficult to debug.
+    logger = logger or default_logger
+    working_dir_path = Path(working_dir)
+    for d in default_excludes:
+        if (working_dir_path / d).exists() and log_once(
+            f"{_LOG_ONCE_DEFAULT_EXCLUDE_PREFIX}{d}"
+        ):
+            logger.warning(
+                "Directory %r is now ignored by default when packaging the working "
+                "directory. To disable this behavior, set "
+                "the `RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES=''` environment "
+                "variable.",
+                d,
+            )
     try:
         working_dir_uri = get_uri_for_directory(
             working_dir,

python/ray/tests/test_runtime_env_working_dir.py

@@ -612,5 +612,54 @@ class B:
         B.options(runtime_env={"working_dir": "."})
 
 
+def test_default_excludes(start_cluster, monkeypatch):
+    """Tests that default excludes (.git, .venv, etc.) are applied."""
+    cluster, address = start_cluster
+    monkeypatch.delenv("RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES", raising=False)
+
+    excluded_dirs = [".git", ".venv", "venv", "__pycache__"]
+
+    with tempfile.TemporaryDirectory() as tmp_working_dir:
+        # Create excluded directories with a marker file
+        for d in excluded_dirs:
+            os.makedirs(os.path.join(tmp_working_dir, d))
+            Path(tmp_working_dir, d, "to_exclude").write_text("x")
+
+        # Create a file that should be included
+        Path(tmp_working_dir, "included.txt").write_text("x")
+
+        ray.init(address, runtime_env={"working_dir": tmp_working_dir})
+
+        @ray.remote
+        def check_dirs(dirs):
+            return {d: os.path.exists(d) for d in dirs + ["included.txt"]}
+
+        result = ray.get(check_dirs.remote(excluded_dirs))
+
+        assert result["included.txt"], "included.txt should be present"
+        for d in excluded_dirs:
+            assert not result[d], f"{d} should be excluded by default"
+
+
+def test_default_excludes_disabled_via_env_var(start_cluster, monkeypatch):
+    """Tests that RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES='' disables defaults."""
+    cluster, address = start_cluster
+    monkeypatch.setenv("RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES", "")
+
+    with tempfile.TemporaryDirectory() as tmp_working_dir:
+        os.makedirs(os.path.join(tmp_working_dir, ".git"))
+        Path(tmp_working_dir, ".git", "to_exclude").write_text("x")
+
+        ray.init(address, runtime_env={"working_dir": tmp_working_dir})
+
+        @ray.remote
+        def check_git():
+            return os.path.exists(".git")
+
+        assert ray.get(
+            check_git.remote()
+        ), ".git should be included when defaults disabled"
+
+
 if __name__ == "__main__":
     sys.exit(pytest.main(["-sv", __file__]))

python/ray/tests/unit/test_runtime_env_working_dir.py

@@ -0,0 +1,30 @@
+"""Unit tests for working_dir runtime environment functionality."""
+
+import sys
+
+import pytest
+
+from ray._private.ray_constants import get_runtime_env_default_excludes
+
+ENV_VAR = "RAY_OVERRIDE_RUNTIME_ENV_DEFAULT_EXCLUDES"
+
+
+class TestGetRuntimeEnvDefaultExcludes:
+    """Tests for get_runtime_env_default_excludes()."""
+
+    def test_returns_defaults_when_env_var_not_set(self, monkeypatch):
+        monkeypatch.delenv(ENV_VAR, raising=False)
+        result = get_runtime_env_default_excludes()
+        assert ".git" in result and ".venv" in result
+
+    def test_empty_env_var_disables_defaults(self, monkeypatch):
+        monkeypatch.setenv(ENV_VAR, "")
+        assert get_runtime_env_default_excludes() == []
+
+    def test_custom_env_var_overrides_defaults(self, monkeypatch):
+        monkeypatch.setenv(ENV_VAR, "foo, bar ,baz")
+        assert get_runtime_env_default_excludes() == ["foo", "bar", "baz"]
+
+
+if __name__ == "__main__":
+    sys.exit(pytest.main(["-vv", __file__]))