use python_version = PY2 for par_binary and py_binary targets

bazelbuild/rules_k8s#305

.bazelrc

@@ -0,0 +1,6 @@
+build --python_top=//python:default_py_runtime
+build --host_force_python=PY2
+test --python_top=//python:default_py_runtime
+test --host_force_python=PY2
+run --python_top=//python:default_py_runtime
+run --host_force_python=PY2

container/BUILD

@@ -30,6 +30,7 @@ py_binary(
     name = "extract_config",
     srcs = ["extract_config.py"],
     legacy_create_init = False,
+    python_version = "PY2",
     visibility = ["//visibility:public"],
     deps = [
         "@containerregistry",
@@ -48,6 +49,7 @@ py_binary(
     name = "join_layers",
     srcs = ["join_layers.py"],
     legacy_create_init = False,
+    python_version = "PY2",
     visibility = ["//visibility:public"],
     deps = [
         ":utils",
@@ -60,6 +62,7 @@ py_binary(
     name = "create_image_config",
     srcs = ["create_image_config.py"],
     legacy_create_init = False,
+    python_version = "PY2",
     visibility = ["//visibility:public"],
     deps = [
         ":utils",

python/BUILD

@@ -27,3 +27,15 @@ py_runtime(
     files = [],
     interpreter_path = "/usr/bin/python2",
 )
+
+# Starting with Bazel 0.25.0 we must pass a py_runtime that points
+# to valid python2 and python3 tools.
+py_runtime(
+    name = "default_py_runtime",
+    interpreter_path = select({
+        # Update paths as appropriate for your system.
+        "@bazel_tools//tools/python:PY2": "/usr/bin/python2",
+        "@bazel_tools//tools/python:PY3": "/usr/bin/python3",
+    }),
+    files = [],
+)

tools/BUILD

@@ -17,6 +17,7 @@ py_binary(
     name = "update_deps",
     srcs = ["update_deps.py"],
     legacy_create_init = False,
+    python_version = "PY2",
     deps = [
         "@containerregistry",
     ],