tests: add OS_IMAGE_TYPE setting to allow for minimal tests (#5682)

Allow setting CLOUD_INIT_OS_IMAGE_TYPE="mimimal" to support
running the full integration test suite against Ubuntu minimal
images.

Required for SC-1750: Daily jenkins ubuntu minimal test runner for
Ubuntu Focal, Jammy and Noble releases.

doc/rtd/development/integration_tests.rst

@@ -263,7 +263,7 @@ the form: ``<image_id>[::<os>::<release>::<version>]`` where ``image_id`` is a
 cloud's image ID, ``os`` is the OS name, and ``release`` is the OS
 release name. So, for example, Ubuntu 24.04 LTS (Noble Numbat) on LXD is
 ``ubuntu:noble::ubuntu::noble::24.04`` or RHEL8 on Amazon is
-``ami-justanexample::rhel::8``. When a full specification is given,
+``ami-justanexample::rhel::9::9.3``. When a full specification is given,
 only tests which are intended for use on that OS and release will be
 executed.
 
@@ -285,6 +285,33 @@ variable to be the desired image specification.
             OS_IMAGE = 'jammy'
 
 
+To run integration tests on a specific type/family of image, modify the
+``OS_IMAGE_TYPE`` variable to be the desired image type. This comes from
+`pycloudlib's ImageType enum`_, which can take the following values:
+
+- "generic"
+- "minimal"
+- "Pro"
+- "Pro FIPS"
+
+.. tab-set::
+
+    .. tab-item:: Inline environment variable
+
+        .. code-block:: bash
+
+            CLOUD_INIT_PLATFORM=lxd_container CLOUD_INIT_OS_IMAGE=noble CLOUD_INIT_OS_IMAGE_TYPE=minimal tox -e integration_tests
+
+    .. tab-item:: user_settings.py file
+
+        .. code-block:: python
+
+            OS_PLATFORM = 'lxd_container'
+            OS_IMAGE = 'noble'
+            OS_IMAGE_TYPE = 'minimal'
+
+Note: Not all clouds and OSes support all image types
+
 Image setup
 ===========
 
@@ -427,3 +454,4 @@ Customizing the launch arguments before launching an instance manually:
 .. _Pytest marks: https://github.com/canonical/cloud-init/blob/af7eb1deab12c7208853c5d18b55228e0ba29c4d/tests/integration_tests/conftest.py#L220-L224
 .. _IntegrationCloud: https://github.com/canonical/cloud-init/blob/af7eb1deab12c7208853c5d18b55228e0ba29c4d/tests/integration_tests/clouds.py#L102
 .. _pycloudlib configuration documentation: https://pycloudlib.readthedocs.io/en/latest/configuration.html
+.. _pycloudlib's ImageType enum: https://github.com/canonical/pycloudlib/blob/1!10.0.0/pycloudlib/cloud.py#L28

integration-requirements.txt

@@ -2,7 +2,7 @@
 # PyPI requirements for cloud-init integration testing
 # https://docs.cloud-init.io/en/latest/development/integration_tests.html
 #
-pycloudlib>=1!6.7.0,<1!9.3
+pycloudlib>=1!9.1.0,<1!10
 
 # Avoid breaking change in `testpaths` treatment forced
 # test/unittests/conftest.py to be loaded by our integration-tests tox env

tests/integration_tests/clouds.py

@@ -275,6 +275,11 @@ class _LxdIntegrationCloud(IntegrationCloud):
     instance_tag: str
     cloud_instance: _BaseLXD
 
+    def _get_initial_image(self, **kwargs) -> str:
+        return super()._get_initial_image(
+            image_type=self._image_type, **kwargs
+        )
+
     def _get_or_set_profile_list(self, release):
         return None
 

tests/integration_tests/conftest.py

@@ -12,6 +12,7 @@
 from typing import Dict, Generator, Iterator, List, Type
 
 import pytest
+from pycloudlib.cloud import ImageType
 from pycloudlib.lxd.instance import LXDInstance
 
 from tests.integration_tests import integration_settings
@@ -80,8 +81,15 @@ def session_cloud() -> Generator[IntegrationCloud, None, None]:
             f"{integration_settings.PLATFORM} is an invalid PLATFORM "
             f"specified in settings. Must be one of {list(platforms.keys())}"
         )
-
-    cloud = platforms[integration_settings.PLATFORM]()
+    image_types = [member.value for member in ImageType.__members__.values()]
+    try:
+        image_type = ImageType(integration_settings.OS_IMAGE_TYPE)
+    except ValueError:
+        raise ValueError(
+            f"{integration_settings.OS_IMAGE_TYPE} is an invalid OS_IMAGE_TYPE"
+            f" specified in settings. Must be one of {image_types}"
+        )
+    cloud = platforms[integration_settings.PLATFORM](image_type=image_type)
     cloud.emit_settings_to_log()
     yield cloud
     cloud.destroy()

tests/integration_tests/integration_settings.py

@@ -39,6 +39,17 @@
 # to this format internally; in this case, to "None::ubuntu::focal::20.04".)
 OS_IMAGE = "focal"
 
+
+# Determines unique image type or flavor to exercise if the cloud supports
+# image-type lookup for daily_image and released_images.
+#
+# One of the following pycloudlib.cloud.ImageType values:
+# - generic
+# - minimal
+# - Pro
+# - Pro FIPS
+OS_IMAGE_TYPE = "generic"
+
 # Populate if you want to use a pre-launched instance instead of
 # creating a new one. The exact contents will be platform dependent
 EXISTING_INSTANCE_ID: Optional[str] = None
@@ -47,6 +58,7 @@
 # IMAGE GENERATION SETTINGS
 ##################################################################
 
+
 # Depending on where we are in the development / test / SRU cycle, we'll want
 # different methods of getting the source code to our SUT. Because of
 # this there are a number of different ways to initialize