Fix runsc --version and add a test.

We need to include the `--stamp` flag in `tools/workspace_status.sh` for
the version to be picked up by the linker. Not sure why.

Also changes the VERSION string to STABLE_VERSION, which will cause the
program to be re-linked if the string changes.

Fixes #830

.bazelrc

@@ -13,7 +13,7 @@
 # limitations under the License.
 
 # Display the current git revision in the info block.
-build --workspace_status_command tools/workspace_status.sh
+build --stamp --workspace_status_command tools/workspace_status.sh
 
 # Enable remote execution so actions are performed on the remote systems.
 build:remote --remote_executor=grpcs://remotebuildexecution.googleapis.com

runsc/BUILD

@@ -13,7 +13,7 @@ go_binary(
     visibility = [
         "//visibility:public",
     ],
-    x_defs = {"main.version": "{VERSION}"},
+    x_defs = {"main.version": "{STABLE_VERSION}"},
     deps = [
         "//pkg/log",
         "//pkg/refs",
@@ -46,7 +46,7 @@ go_binary(
     visibility = [
         "//visibility:public",
     ],
-    x_defs = {"main.version": "{VERSION}"},
+    x_defs = {"main.version": "{STABLE_VERSION}"},
     deps = [
         "//pkg/log",
         "//pkg/refs",
@@ -101,3 +101,10 @@ pkg_deb(
         "//visibility:public",
     ],
 )
+
+sh_test(
+    name = "version_test",
+    data = [":runsc"],
+    size = "small",
+    srcs = ["version_test.sh"],
+)

runsc/version.go

@@ -15,4 +15,4 @@
 package main
 
 // version is set during linking.
-var version = ""
+var version = "VERSION_MISSING"

runsc/version_test.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# Copyright 2018 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.
+
+set -euf -x -o pipefail
+
+readonly runsc="${TEST_SRCDIR}/__main__/runsc/linux_amd64_pure_stripped/runsc"
+readonly version=$($runsc --version)
+
+# Version should should not match VERSION, which is the default and which will
+# also appear if something is wrong with workspace_status.sh script.
+if [[ $version =~ "VERSION" ]]; then
+  echo "Got bad version $version"
+  exit 1
+fi
+
+echo "Got OK version $version"
+exit 0

tools/workspace_status.sh

@@ -14,4 +14,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-echo VERSION $(git describe --always --tags --abbrev=12 --dirty)
+# The STABLE_ prefix will triger a re-link if it changes.
+echo STABLE_VERSION $(git describe --always --tags --abbrev=12 --dirty)