[gsutil] run through "vpython" (2)

Run "gsutil" through "vpython". This ensures that the package set
accompanying it is completely controlled. This is notably important on
GCE instances, which "gsutil" expects to supply a
"google_compute_engine" package.

BUG=chromium:741001
TEST=local
  - Ran `gsutil cp` on 64-bit Linux machine, seems to work.
  - Ran `gsutil cp` on GCE instance, seems to work.

This is a reland of 23836a643f480b21e91340f2f9845619ebf6f9c4.

Change-Id: If87261abd505ef77f95b3c70b6bd23f3e798b41d
Reviewed-on: https://chromium-review.googlesource.com/656565
Reviewed-by: Nodir Turakulov <nodir@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Daniel Jacques <dnj@chromium.org>
diff --git a/gsutil.vpython b/gsutil.vpython
new file mode 100644
index 0000000..caadd5c
--- /dev/null
+++ b/gsutil.vpython
@@ -0,0 +1,102 @@
+# vpython VirtualEnv protobuf for "gsutil".
+#
+# See:
+# https://chromium.googlesource.com/infra/luci/luci-go/+/master/vpython/api/vpython/spec.proto
+#
+# This is a "vpython" VirtualEnv specification applied to invocations of "gsutil"
+# by the bootstrap wrapper, "gsutil.py". It ensures that any Python distribution
+# has the expected Python packages installed.
+#
+# This is specifically relevant on Google Compute Engine invocations of
+# "gsutil", where a stock system-deployed file in "/etc/" explicitly specifies
+# that the "google_compute_engine" and "boto" Python packages are available.
+
+wheel <
+  name: "infra/python/wheels/google_compute_engine-py2_py3"
+  version: "version:2.3.7"
+>
+wheel <
+  name: "infra/python/wheels/boto-py2_py3"
+  version: "version:2.47.0"
+>
+
+# "gsutil" on non-GCE can require PyOpenSSL, which, in turn, requires
+# "cryptography".
+
+wheel: <
+  name: "infra/python/wheels/pyopenssl-py2_py3"
+  version: "version:17.2.0"
+>
+
+##
+# BEGIN "cryptography" dependencies.
+##
+
+wheel: <
+  name: "infra/python/wheels/cryptography/${platform}_${py_python}_${py_abi}"
+  version: "version:2.0.3"
+>
+
+wheel: <
+  name: "infra/python/wheels/appdirs-py2_py3"
+  version: "version:1.4.3"
+>
+
+wheel: <
+  name: "infra/python/wheels/asn1crypto-py2_py3"
+  version: "version:0.22.0"
+>
+
+wheel: <
+  name: "infra/python/wheels/enum34-py2"
+  version: "version:1.1.6"
+>
+
+wheel: <
+  name: "infra/python/wheels/cffi/${platform}_${py_python}_${py_abi}"
+  version: "version:1.10.0"
+>
+
+wheel: <
+  name: "infra/python/wheels/idna-py2_py3"
+  version: "version:2.5"
+>
+
+wheel: <
+  name: "infra/python/wheels/ipaddress-py2"
+  version: "version:1.0.18"
+>
+
+wheel: <
+  name: "infra/python/wheels/packaging-py2_py3"
+  version: "version:16.8"
+>
+
+wheel: <
+  name: "infra/python/wheels/pyasn1-py2_py3"
+  version: "version:0.2.3"
+>
+
+wheel: <
+  name: "infra/python/wheels/pycparser-py2_py3"
+  version: "version:2.17"
+>
+
+wheel: <
+  name: "infra/python/wheels/pyparsing-py2_py3"
+  version: "version:2.2.0"
+>
+
+wheel: <
+  name: "infra/python/wheels/setuptools-py2_py3"
+  version: "version:34.3.2"
+>
+
+wheel: <
+  name: "infra/python/wheels/six-py2_py3"
+  version: "version:1.10.0"
+>
+
+##
+# END "cryptography" dependencies.
+##