Mitigate #18256

WORKSPACE

@@ -17,20 +17,13 @@ register_toolchains(
     "//third_party/toolchains:cc-toolchain-clang-x86_64-default",
 )
 
-http_archive(
-    name = "cython",
-    build_file = "//third_party:cython.BUILD",
-    sha256 = "d68138a2381afbdd0876c3cb2a22389043fa01c4badede1228ee073032b07a27",
-    strip_prefix = "cython-c2b80d87658a8525ce091cbe146cb7eaa29fed5c",
-    urls = [
-        "https://github.com/cython/cython/archive/c2b80d87658a8525ce091cbe146cb7eaa29fed5c.tar.gz",
-    ],
+# TODO(https://github.com/grpc/grpc/issues/18331): Move off of this dependency.
+git_repository(
+    name = "org_pubref_rules_protobuf",
+    remote = "https://github.com/ghostwriternr/rules_protobuf",
+    tag = "v0.8.2.1-alpha",
 )
 
-load("//third_party/py:python_configure.bzl", "python_configure")
-
-python_configure(name = "local_config_python")
-
 git_repository(
     name = "io_bazel_rules_python",
     commit = "8b5d0683a7d878b28fffe464779c8a53659fc645",
@@ -39,24 +32,21 @@ git_repository(
 
 load("@io_bazel_rules_python//python:pip.bzl", "pip_repositories", "pip_import")
 
-pip_repositories()
-
 pip_import(
     name = "grpc_python_dependencies",
     requirements = "//:requirements.bazel.txt",
 )
 
-load("@grpc_python_dependencies//:requirements.bzl", "pip_install")
-
-pip_install()
-
-# NOTE(https://github.com/pubref/rules_protobuf/pull/196): Switch to upstream repo after this gets merged.
-git_repository(
-    name = "org_pubref_rules_protobuf",
-    remote = "https://github.com/ghostwriternr/rules_protobuf",
-    tag = "v0.8.2.1-alpha",
+http_archive(
+    name = "cython",
+    build_file = "//third_party:cython.BUILD",
+    sha256 = "d68138a2381afbdd0876c3cb2a22389043fa01c4badede1228ee073032b07a27",
+    strip_prefix = "cython-c2b80d87658a8525ce091cbe146cb7eaa29fed5c",
+    urls = [
+        "https://github.com/cython/cython/archive/c2b80d87658a8525ce091cbe146cb7eaa29fed5c.tar.gz",
+    ],
 )
 
-load("@org_pubref_rules_protobuf//python:rules.bzl", "py_proto_repositories")
+load("//bazel:grpc_python_deps.bzl", "grpc_python_deps")
 
-py_proto_repositories()
+grpc_python_deps()

bazel/grpc_python_deps.bzl

@@ -0,0 +1,15 @@
+load("//third_party/py:python_configure.bzl", "python_configure")
+load("@io_bazel_rules_python//python:pip.bzl", "pip_repositories")
+load("@grpc_python_dependencies//:requirements.bzl", "pip_install")
+load("@org_pubref_rules_protobuf//python:rules.bzl", "py_proto_repositories")
+
+def grpc_python_deps():
+    # TODO(https://github.com/grpc/grpc/issues/18256): Remove conditional.
+    if hasattr(native, "http_archive"):
+        python_configure(name = "local_config_python")
+        pip_repositories()
+        pip_install()
+        py_proto_repositories()
+    else:
+        print("Building python gRPC with bazel 23.0+ is disabled pending resolution of https://github.com/grpc/grpc/issues/18256.")
+