swarming: refactor cipd input

appengine/swarming/swarming_rpcs.py

Index: appengine/swarming/swarming_rpcs.py
diff --git a/appengine/swarming/swarming_rpcs.py b/appengine/swarming/swarming_rpcs.py
index b9f61c49be939eb7e19bb2c80fd987a54a2f3060..71451bdd6bf6086c1697029eeaf70d3a89c8f6a6 100644
--- a/appengine/swarming/swarming_rpcs.py
+++ b/appengine/swarming/swarming_rpcs.py
@@ -84,14 +84,32 @@ class FilesRef(messages.Message):
 
 class CipdPackage(messages.Message):
   """A CIPD package to install in $CIPD_PATH and $PATH before task execution."""
-  # Full CIPD package name, e.g. "infra/tools/authutil/linux-amd64"
+  # A template of a full CIPD package name, e.g.
+  # "infra/tools/authutil/${platform}"
+  # See also cipd.ALL_PARAMS.
   package_name = messages.StringField(1)
-  # Instance ID, tag or ref, e.g. "latest".
+  # Valid package version for all packages matched by package name.
   version = messages.StringField(2)
 
 
+class CipdInput(messages.Message):
+  """Defines CIPD packages to install in $CIPD_PATH.
+
+  A command may use $CIPD_PATH in its arguments. It will be expanded to the path
+  of the CIPD site root.
+  """
+  # Serialized config_pb2.CipdSettings message. When creating a new task
+  # this field can override cipd settings defined on the server,
+  # for testing purposes.
+  # This field is optional if default settings are configured on the server.
+  settings = messages.BytesField(1)

[M-A Ruel, 2016/05/11 14:56:45]

why not expand it? I'd prefer that to encoded protobuf.

[nodir, 2016/05/12 01:53:22]

Done. This lead to rethinking of how I embed cipd server url and cipd client
package in task properties, which in turn lead to overall simplification. I no
longer embed CipdSettings message in TaskProperties, but instead TaskProperties
has "server" and "client_package" fields. In the new task request handler, these
values are defaulted to the values defined in the server config, just like
isolate defaults. Now ndb models, rpc models, message conversion and all tests
do not deal with proto. PTAL

+  # List of CIPD packages to install in $CIPD_PATH prior task execution.
+  packages = messages.MessageField(CipdPackage, 2, repeated=True)
+
+
 class TaskProperties(messages.Message):
   """Important metadata about a particular task."""
+  cipd_input = messages.MessageField(CipdInput, 10)
   command = messages.StringField(1, repeated=True)
   dimensions = messages.MessageField(StringPair, 2, repeated=True)
   env = messages.MessageField(StringPair, 3, repeated=True)
@@ -101,7 +119,6 @@ class TaskProperties(messages.Message):
   idempotent = messages.BooleanField(7)
   inputs_ref = messages.MessageField(FilesRef, 8)
   io_timeout_secs = messages.IntegerField(9)
-  packages = messages.MessageField(CipdPackage, 10, repeated=True)
 
 
 class NewTaskRequest(messages.Message):