Add a functional vm_test for root_test.

This change renames the tools/images directory to tools/vm for clarity, and
adds a functional vm_test. Sharding is also added to the same test, and some
documentation added around key flags & variables to describe how they work.

Subsequent changes will add vm_tests for other cases, such as the runtime tests.

PiperOrigin-RevId: 307492245

1 files changed, 27 insertions, 0 deletions

diff --git a/tools/vm/test.cc b/tools/vm/test.cc
new file mode 100644
index 000000000..c0ceacda1
--- /dev/null
+++ b/tools/vm/test.cc
@@ -0,0 +1,27 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "gtest/gtest.h"
+
+namespace {
+
+TEST(Image, Sanity0) {
+  // Do nothing (in shard 0).
+}
+
+TEST(Image, Sanity1) {
+  // Do nothing (in shard 1).
+}
+
+}  // namespace