GCloudProducer: tunnel_dispatch, mock_recorder, and machine.

Work to import GCloudProducer, written in gerrit, which is
too large to do in one CL. GCloudProducer sets up gcloud
instances to run benchmark workloads.

Included are:
- gcloud_mock_recorder - used to Mock GCloudProducer
- tunnel_dispatcher - updates to this module to bring it in line
with the style guide
- machine - updates to this module to bring it in line with the
 style guide

All changes are independent of the rest of the changes, and
should "just build".

PiperOrigin-RevId: 285076423

2 files changed, 102 insertions, 0 deletions

diff --git a/benchmarks/harness/machine_producers/BUILD b/benchmarks/harness/machine_producers/BUILD
index 5b2228e01..a48da02a1 100644
--- a/benchmarks/harness/machine_producers/BUILD
+++ b/benchmarks/harness/machine_producers/BUILD
@@ -33,3 +33,8 @@ py_library(
         requirement("PyYAML", False),
     ],
 )
+
+py_library(
+    name = "gcloud_mock_recorder",
+    srcs = ["gcloud_mock_recorder.py"],
+)
diff --git a/benchmarks/harness/machine_producers/gcloud_mock_recorder.py b/benchmarks/harness/machine_producers/gcloud_mock_recorder.py
new file mode 100644
index 000000000..fd9837a37
--- /dev/null
+++ b/benchmarks/harness/machine_producers/gcloud_mock_recorder.py
@@ -0,0 +1,97 @@
+# python3
+# Copyright 2019 Google LLC
+#
+# 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.
+"""A recorder and replay for testing the GCloudProducer.
+
+MockPrinter and MockReader handle printing and reading mock data for the
+purposes of testing. MockPrinter is passed to GCloudProducer objects. The user
+can then run scenarios and record them for playback in tests later.
+
+MockReader is passed to MockGcloudProducer objects and handles reading the
+previously recorded mock data.
+
+It is left to the user to check if data printed is properly redacted for their
+own use. The intended usecase for this class is data coming from gcloud
+commands, which will contain public IPs and other instance data.
+
+The data format is json and printed/read from the ./test_data directory. The
+data is the output of subprocess.CompletedProcess objects in json format.
+
+  Typical usage example:
+
+  recorder = MockPrinter()
+  producer = GCloudProducer(args, recorder)
+  machines = producer.get_machines(1)
+  with open("my_file.json") as fd:
+    recorder.write_out(fd)
+
+  reader = MockReader(filename)
+  producer = MockGcloudProducer(args, mock)
+  machines = producer.get_machines(1)
+  assert len(machines) == 1
+"""
+
+import io
+import json
+import subprocess
+
+
+class MockPrinter(object):
+  """Handles printing Mock data for MockGcloudProducer.
+
+  Attributes:
+    _records: list of json object records for printing
+  """
+
+  def __init__(self):
+    self._records = []
+
+  def record(self, entry: subprocess.CompletedProcess):
+    """Records data and strips out ip addresses."""
+
+    record = {
+        "args": entry.args,
+        "stdout": entry.stdout.decode("utf-8"),
+        "returncode": str(entry.returncode)
+    }
+    self._records.append(record)
+
+  def write_out(self, fd: io.FileIO):
+    """Prints out the data into the given filepath."""
+    fd.write(json.dumps(self._records, indent=4))
+
+
+class MockReader(object):
+  """Handles reading Mock data for MockGcloudProducer.
+
+  Attributes:
+    _records: List[json] records read from the passed in file.
+  """
+
+  def __init__(self, filepath: str):
+    with open(filepath, "rb") as file:
+      self._records = json.loads(file.read())
+      self._i = 0
+
+  def __iter__(self):
+    return self
+
+  def __next__(self, args) -> subprocess.CompletedProcess:
+    """Returns the next record as a CompletedProcess."""
+    if self._i < len(self._records):
+      record = self._records[self._i]
+      stdout = record["stdout"].encode("ascii")
+      returncode = int(record["returncode"])
+      return subprocess.CompletedProcess(
+          args=args, returncode=returncode, stdout=stdout, stderr=b"")
+    raise StopIteration()