PULUMI_TEST_MODE environment variable doesn't work in Python

[clstokes]

The PULUMI_TEST_MODE environment variable doesn't work for Python applications. Instead users must set a flag programmatically in their Python application as shown below (for posterity's sake).

The PULUMI_TEST_MODE environment variable should work for all supported Pulumi languages. We should also document this officially.

For reference:

import pulumi
import unittest
import asyncio

# Import the Pulumi SDK and turn on test mode *before* allocating anything.

pulumi.runtime.settings._set_test_mode_enabled(True)    # This should be able to be set via PULUMI_TEST_MODE
pulumi.runtime.settings._set_project('webserver')
pulumi.runtime.settings._set_stack('test')

# Tests come next:


def async_test(coro):
    def wrapper(*args, **kwargs):
        loop = asyncio.new_event_loop()
        loop.run_until_complete(coro(*args, **kwargs))
        loop.close()
    return wrapper


class InstanceTests(unittest.TestCase):
    @async_test
    async def test_no_internet_access(self):
        # Now import the infrastructure module which will allocate our resource objects.
        from infra import group, server

        # Rendezvous with the resource's resulting ingress rules.
        ingress_fut = asyncio.Future()
        group.ingress.apply(lambda ig: ingress_fut.set_result(ig))
        ingress = await ingress_fut

        # Now loop through them and reject any that are open to the Internet (0.0.0.0/0).
        for rule in ingress:
            for cidr in rule['cidr_blocks']:
                self.assertNotEqual('0.0.0.0/0', cidr)