inputs: add inputs_service fixture

This new fixture avoids some repetitivness when building tests
for input services.

inputs/test/test_containers.py

@@ -7,7 +7,6 @@ import tempfile
 
 import pytest
 
-from osbuild import testutil
 from osbuild.testutil import has_executable, make_container
 
 INPUTS_NAME = "org.osbuild.containers-storage"
@@ -26,7 +25,7 @@ class FakeStoreClient:
 
 @pytest.mark.skipif(not has_executable("podman"), reason="no podman executable")
 @pytest.mark.skipif(os.getuid() != 0, reason="root only")
-def test_containers_local_inputs_integration(tmp_path, inputs_module):
+def test_containers_local_inputs_integration(tmp_path, inputs_service):
     with make_container(tmp_path, {"file1": "file1 content"}) as base_tag:
         image_id = subprocess.check_output(
             ["podman", "inspect", "-f", "{{ .Id }}", base_tag],
@@ -40,8 +39,6 @@ def test_containers_local_inputs_integration(tmp_path, inputs_module):
                 }
             }
         }
-        fd = testutil.make_fake_service_fd()
-        cnt_inputs = inputs_module.ContainersStorageInput.from_args(["--service-fd", str(fd)])
         store = FakeStoreClient(tmp_path / "fake-sources")
         # not using "tmp_path" here as it will "rm -rf" on cleanup and
         # that is dangerous as during the tests we bind mount the
@@ -49,12 +46,12 @@ def test_containers_local_inputs_integration(tmp_path, inputs_module):
         target = pathlib.Path(tempfile.TemporaryDirectory("cnt-target").name)
         options = None
         try:
-            reply = cnt_inputs.map(store, inputs["origin"], inputs["references"], target, options)
+            reply = inputs_service.map(store, inputs["origin"], inputs["references"], target, options)
             assert reply["path"] == target
             assert len(reply["data"]["archives"]) == 1
             assert (target / "storage").exists()
         finally:
-            cnt_inputs.unmap()
+            inputs_service.unmap()
             # cleanup manually, note that we only remove empty dirs here,
             # because we only expect a bind mount under "$target/storage"
             # Anything non-empty here means a umount() failed