refactor(tests): drop test_context decorator

The same thing can be done with a fixture, without having to resort to
pytest hooks.

Signed-off-by: Pablo Barbáchano <[email protected]>

Author: pb8o

tests/conftest.py

@@ -497,39 +497,6 @@ def test_microvm_any(request, microvm):
     yield microvm
 
 
-@pytest.fixture
-def test_multiple_microvms(test_fc_session_root_path, context, bin_cloner_path):
-    """Yield one or more microvms based on the context provided.
-
-    `context` is a dynamically parameterized fixture created inside the special
-    function `pytest_generate_tests` and it holds a tuple containing the name
-    of the guest image used to spawn a microvm and the number of microvms
-    to spawn.
-    """
-    microvms = []
-    (microvm_resources, how_many) = context
-
-    # When the context specifies multiple microvms, we use the first vm to
-    # populate the other ones by hardlinking its resources.
-    first_vm = init_microvm(test_fc_session_root_path, bin_cloner_path)
-    MICROVM_S3_FETCHER.init_vm_resources(microvm_resources, first_vm)
-    microvms.append(first_vm)
-
-    # It is safe to do this as the dynamically generated fixture `context`
-    # asserts that the `how_many` parameter is always positive
-    # (i.e strictly greater than 0).
-    for _ in range(how_many - 1):
-        vm = init_microvm(test_fc_session_root_path, bin_cloner_path)
-        MICROVM_S3_FETCHER.hardlink_vm_resources(microvm_resources, first_vm, vm)
-        microvms.append(vm)
-
-    yield microvms
-
-    for i in range(how_many):
-        microvms[i].kill()
-        shutil.rmtree(os.path.join(test_fc_session_root_path, microvms[i].id))
-
-
 @pytest.fixture(autouse=True, scope="session")
 def test_spectre_mitigations():
     """Check the kernel is compiled with SPECTREv2 mitigations."""
@@ -582,45 +549,6 @@ def firecracker_release(request):
     return firecracker
 
 
-def pytest_generate_tests(metafunc):
-    """Implement customized parametrization scheme.
-
-    This is a special hook which is called by the pytest infrastructure when
-    collecting a test function. The `metafunc` contains the requesting test
-    context. Amongst other things, the `metafunc` provides the list of fixture
-    names that the calling test function is using.  If we find a fixture that
-    is called `context`, we check the calling function through the
-    `metafunc.function` field for the `_pool_size` attribute which we
-    previously set with a decorator. Then we create the list of parameters
-    for this fixture.
-    The parameter will be a list of tuples of the form (cap, pool_size).
-    For each parameter from the list (i.e. tuple) a different test case
-    scenario will be created.
-    """
-    if "context" in metafunc.fixturenames:
-        # In order to create the params for the current fixture, we need the
-        # capability and the number of vms we want to spawn.
-
-        # 1. Look if the test function set the pool size through the decorator.
-        # If it did not, we set it to 1.
-        how_many = int(getattr(metafunc.function, "_pool_size", None))
-        assert how_many > 0
-
-        # 2. Check if the test function set the capability field through
-        # the decorator. If it did not, we set it to any.
-        cap = getattr(metafunc.function, "_capability", "*")
-
-        # 3. Before parametrization, get the list of images that have the
-        # desired capability. By parametrize-ing the fixture with it, we
-        # trigger tests cases for each of them.
-        image_list = MICROVM_S3_FETCHER.list_microvm_images(capability_filter=[cap])
-        metafunc.parametrize(
-            "context",
-            [(item, how_many) for item in image_list],
-            ids=["{}, {} instance(s)".format(item, how_many) for item in image_list],
-        )
-
-
 @pytest.fixture(params=ARTIFACTS_COLLECTION.kernels(), ids=lambda kernel: kernel.name())
 def guest_kernel(request):
     """Return all supported guest kernels."""

tests/framework/decorators.py

@@ -46,14 +46,3 @@ def timed(*args, **kwargs):
         return result
 
     return timed
-
-
-def test_context(cap, count=1):
-    """Set the image capability and vm count attribute for individual tests."""
-
-    def wrap(func):
-        setattr(func, "_capability", cap)
-        setattr(func, "_pool_size", count)
-        return func
-
-    return wrap

tests/framework/s3fetcher.py

@@ -143,48 +143,6 @@ def init_vm_resources(self, microvm_image_name, microvm):
                 microvm.ssh_config["ssh_key_path"] = microvm_dest_path
                 os.chmod(microvm_dest_path, 0o400)
 
-    def hardlink_vm_resources(self, microvm_image_name, from_microvm, to_microvm):
-        """Hardlink resources from one microvm to another.
-
-        Assumes the correct microvm image structure for the source vm specified
-        by the `from_microvm` parameter and copies all necessary resources into
-        the destination microvm specified through the `to_microvm` parameter.
-        """
-        for resource_key in self._microvm_images[microvm_image_name]:
-            if resource_key in [
-                self.MICROVM_IMAGE_KERNEL_RELPATH,
-                self.MICROVM_IMAGE_BLOCKDEV_RELPATH,
-            ]:
-                # Kernel and blockdev dirs already exist in the microvm's
-                # allocated resources.
-                continue
-
-            microvm_dest_path = os.path.join(to_microvm.path, resource_key)
-            microvm_source_path = os.path.join(from_microvm.path, resource_key)
-
-            if resource_key.endswith("/"):
-                # Create a new microvm_directory if one is encountered.
-                os.mkdir(microvm_dest_path)
-                continue
-
-            if not os.path.exists(microvm_dest_path):
-                os.link(microvm_source_path, microvm_dest_path)
-
-            if resource_key.endswith(self.MICROVM_IMAGE_KERNEL_FILE_SUFFIX):
-                to_microvm.kernel_file = microvm_dest_path
-
-            if resource_key.endswith(self.MICROVM_IMAGE_ROOTFS_FILE_SUFFIX):
-                to_microvm.rootfs_file = microvm_dest_path
-
-            if resource_key.endswith(self.MICROVM_IMAGE_INITRD_FILE_SUFFIX):
-                to_microvm.initrd_file = microvm_dest_path
-
-            if resource_key.endswith(self.MICROVM_IMAGE_SSH_KEY_SUFFIX):
-                # Add the key path to the config dictionary and set
-                # permissions.
-                to_microvm.ssh_config["ssh_key_path"] = microvm_dest_path
-                os.chmod(microvm_dest_path, 0o400)
-
     def list_microvm_images(self, capability_filter: List[str] = None):
         """Return microvm images with the specified capabilities."""
         capability_filter = capability_filter or ["*"]

tests/integration_tests/functional/test_concurrency.py

@@ -2,42 +2,25 @@
 # SPDX-License-Identifier: Apache-2.0
 """Ensure multiple microVMs work correctly when spawned simultaneously."""
 
-from framework import decorators
-
 import host_tools.network as net_tools
 
 NO_OF_MICROVMS = 20
 
 
-@decorators.test_context("api", NO_OF_MICROVMS)
-def test_run_concurrency(test_multiple_microvms, network_config):
+def test_run_concurrency(microvm_factory, network_config, guest_kernel, rootfs):
     """
     Check we can spawn multiple microvms.
 
     @type: functional
     """
-    microvms = test_multiple_microvms
 
     for i in range(NO_OF_MICROVMS):
-        microvm = microvms[i]
-        _ = _configure_and_run(microvm, {"config": network_config, "iface_id": str(i)})
+        microvm = microvm_factory.build(guest_kernel, rootfs)
+        microvm.spawn()
+        microvm.basic_config(vcpu_count=1, mem_size_mib=128)
+        microvm.ssh_network_config(network_config, str(i))
+        microvm.start()
+
         # We check that the vm is running by testing that the ssh does
         # not time out.
-        _ = net_tools.SSHConnection(microvm.ssh_config)
-
-
-def _configure_and_run(microvm, network_info):
-    """Auxiliary function for configuring and running microVM."""
-    microvm.spawn()
-
-    # Machine configuration specified in the SLA.
-    config = {"vcpu_count": 1, "mem_size_mib": 128}
-
-    microvm.basic_config(**config)
-
-    _tap, _, _ = microvm.ssh_network_config(
-        network_info["config"], network_info["iface_id"]
-    )
-
-    microvm.start()
-    return _tap
+        net_tools.SSHConnection(microvm.ssh_config)