This change gets enough of the Python SDK up and running that the
empty Python program will work. Mostly just scaffolding, but the
basic structure is now in place. The primary remaining work is to
wire up resource creation to the gRPC interfaces.
In summary:
* The basic structure is as follows:
- Everything goes into sdk/python/.
- sdk/python/cmd/pulumi-langhost-python is a Go language host
that simply knows how to spawn Python processes to run out
entrypoint in response to requests by the engine.
- sdk/python/cmd/pulumi-langhost-python-exec is a little Python
shim that is invoked by the language host to run Python programs,
and is responsible for setting up the minimal goo before we can
do so (RPC connections and the like).
- sdk/python/lib/ contains a Python Pip package suitable for PyPi.
- In there, we have two packages: the root pulumi package that
contains all of the basic Pulumi programming model abstractions,
and pulumi.runtime, which contains the implementation of
resource registration, RPC interfacing with the engine, and so on.
* Add logic in our test framework to conditionalize on the language
type and react accordingly. This will allow us to skip Yarn for
Python projects and eventually run Pip if there's a requirements.txt.
* Created the basic project structure, including all of the usual
Make targets for installing into the proper places.
* Building also runs Pylint and we are clean.
There are a few other minor things in here:
* Add an "empty" test for both Node.js and Python. These pass.
* Fix an existing bug in plugin shutdown logic. At some point, we
started waiting for stderr/stdout to flush before shutting down
the plugin; but if certain failures happen "early" during the
plugin launch process, these channels will never get initialized
and so waiting for them deadlocks.
* Recently we seem to have added logic to delete test temp
directories if a failure happened during initialization of said
temp directories. This is unfortunate, because you often need to
look at the temp directory to see what failed. We already clean
them up elsewhere after the full test completes successfully, so
I don't think we need to be doing this, and I've removed it.
Still many loose ends (config, resources, etc), but it's a start!