e1a52693dc
A resource can be imported by setting the `import` property in the resource options bag when instantiating a resource. In order to successfully import a resource, its desired configuration (i.e. its inputs) must not differ from its actual configuration (i.e. its state) as calculated by the resource's provider. There are a few interesting state transitions hiding here when importing a resource: 1. No prior resource exists in the checkpoint file. In this case, the resource is simply imported. 2. An external resource exists in the checkpoint file. In this case, the resource is imported and the old external state is discarded. 3. A non-external resource exists in the checkpoint file and its ID is different from the ID to import. In this case, the new resource is imported and the old resource is deleted. 4. A non-external resource exists in the checkpoint file, but the ID is the same as the ID to import. In this case, the import ID is ignored and the resource is treated as it would be in all cases except for changes that would replace the resource. In that case, the step generator issues an error that indicates that the import ID should be removed: were we to move forward with the replace, the new state of the stack would fall under case (3), which is almost certainly not what the user intends. Fixes #1662. |
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|---|---|---|
| .. | ||
| asset | ||
| chained_failure | ||
| component_resource_list_of_providers | ||
| component_resource_single_provider | ||
| config | ||
| delete_before_replace | ||
| empty | ||
| first_class_provider | ||
| first_class_provider_invoke | ||
| first_class_provider_unknown | ||
| future_input | ||
| ignore_changes | ||
| inherit_defaults | ||
| invalid_property_dependency | ||
| invoke | ||
| one_complex_resource | ||
| one_resource | ||
| output_all | ||
| output_nested | ||
| outputs_future | ||
| preview | ||
| property_dependencies | ||
| property_renaming | ||
| protect | ||
| read | ||
| resource_op_fail | ||
| resource_thens | ||
| runtime_settings | ||
| stack_output | ||
| ten_resources | ||
| versions | ||
| __init__.py | ||
| README.md | ||
| util.py | ||
Python Language Host Tests
The tests in this directory test the language host directly by posing as the engine and running programs in the same context that they would be run by the CLI. Programs run by these tests can create resources, read resource, invoke data sources, and generally do anything that a Pulumi program can do.
Language host tests provide a program to be run and an implementation
of the LanghostTest class, which provides implementations for the
four resource monitor endpoints that the language host speaks to:
invoke, for invoking data sources,read_resource, for reading existing resources,register_resource, for creating new resources,register_resource_outputs, for registering outputs on component resources
Classes deriving from LanghostTest can override any of these methods
to provide custom test functionality. This is commonly used to perform assertions
or place the language host in unexpected situations.
Adding a new test
To add a new language host test, you can:
- Create a new directory in this directory with the name of your test
- Place an
__init__.pyand__main__.pyin this directory.__init__.pyconvinces Python that this directory is a module, while__main__.pyindicates to Python that this module is runnable. - Write your Pulumi program in
__main__.py. If you want to do assertions, use theassertkeyword to do so. - Add a test file, which can have any name. In this test file you'll want to provide a
subclass of
LanghostTestthat drives your test. An example minimal test would be something like this:
from os import path
from ..util import LanghostTest
class EmptyTests(LanghostTest):
def test_empty(self):
self.run_test(
program=path.join(self.base_path(), "empty"), # If your test is in the empty/ subdirectory
expected_resource_count=0) # Assert there are 0 resource registrations
Your class can have any number of test_* methods in them. Language host tests are launched by
invoking the run_test method inherited from LanghostTest. run_test accepts the following
keyword arguments:
project- The name of the project that will be exposed to the running programstack- The name of the stack that will be exposed to the running programprogram- A path to the program to be run, relative to the working directory.pwd- The working directory to use.args- Command-line arguments to pass to the program.config- A dict of configuration keys and values to pass to the program.expected_resource_count- The number of resources this test is expected to register.expected_error- If non-None, the exact error text that is expected to be received.expected_stderr_contains- If non-None, asserts that the given substring exists in stderr
If expected_error is None, the expected error is asserted to be the empty string.
Note that your test method must begin with test_*, since this is how Python discovers what
tests to run.
One additional thing to note is that this test harness explicitly ignores the registration
of the top-level Stack resource, pulumi:pulumi:Stack, because it is annoying to write tests around.
All expected resource counts do not count this resource as a registration and overridden resource monitor
methods will never see a registration for pulumi:pulumi:Stack.