Add unit test for DisableCgroup, RestrictOOMScoreAdj.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/sandbox_run_test.go

@@ -691,5 +691,20 @@ func TestGetSandboxRuntime(t *testing.T) {
 	}
 }
 
+func TestSandboxDisableCgroup(t *testing.T) {
+	config, imageConfig, _ := getRunPodSandboxTestData()
+	c := newTestCRIService()
+	c.config.DisableCgroup = true
+	spec, err := c.generateSandboxContainerSpec("test-id", config, imageConfig, "test-cni")
+	require.NoError(t, err)
+
+	t.Log("resource limit should not be set")
+	assert.Nil(t, spec.Linux.Resources.Memory)
+	assert.Nil(t, spec.Linux.Resources.CPU)
+
+	t.Log("cgroup path should be empty")
+	assert.Empty(t, spec.Linux.CgroupsPath)
+}
+
 // TODO(random-liu): [P1] Add unit test for different error cases to make sure
 // the function cleans up on error properly.