Add in simple metrics for acloud.

Right now we record when a user calls acloud and their git config
username (only if they're a googler).

Bug: 118312364
Test: acloud create registered an uptick in usage
Change-Id: If3af3b0644bf5b19f6400400254cf0b270a4d466
diff --git a/metrics/metrics.py b/metrics/metrics.py
new file mode 100644
index 0000000..87b439e
--- /dev/null
+++ b/metrics/metrics.py
@@ -0,0 +1,50 @@
+# Copyright 2018 - The Android Open Source Project
+#
+# 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.
+r"""Acloud metrics functions."""
+
+import logging
+import os
+import subprocess
+
+from acloud.internal import constants
+# pylint: disable=import-error
+from asuite import asuite_metrics
+
+_METRICS_URL = 'http://asuite-218222.appspot.com/acloud/metrics'
+_VALID_DOMAINS = ["google.com", "android.com"]
+_COMMAND_GIT_CONFIG = ["git", "config", "--get", "user.email"]
+
+logger = logging.getLogger(__name__)
+
+
+def LogUsage():
+    """Log acloud run."""
+    asuite_metrics.log_event(_METRICS_URL, dummy_key_fallback=False,
+                             ldap=_GetLdap())
+
+
+def _GetLdap():
+    """Return string email username for valid domains only, None otherwise."""
+    try:
+        acloud_project = os.path.join(
+            os.environ[constants.ENV_ANDROID_BUILD_TOP], "tools", "acloud")
+        email = subprocess.check_output(_COMMAND_GIT_CONFIG,
+                                        cwd=acloud_project).strip()
+        ldap, domain = email.split("@", 2)
+        if domain in _VALID_DOMAINS:
+            return ldap
+    # pylint: disable=broad-except
+    except Exception as e:
+        logger.debug("error retrieving email: %s", e)
+    return None