Add a docstring for fistpoint

Signed-off-by: Damien Thenot <[email protected]>

Author: Nambrok

lib/fistpoint.py

@@ -1,12 +1,32 @@
 import logging
-from typing import Final
 
 from lib.host import Host
 
+from typing import Final
+
 FISTPOINT_DIR: Final = "/tmp"
 LVHDRT_EXIT_FIST: Final = "fist_LVHDRT_exit"
 
+
 class FistPoint:
+    """
+    A fistpoint is an action that you can enable in the smapi for tests.
+
+    It allows for example, add a sleep at some point or raise an exception.
+    For example:
+    ```
+    with FistPoint(vm.host, "blktap_activate_inject_failure"):
+        with pytest.raises(SSHCommandFailed):
+            vm.start()
+            vm.shutdown(force=True)
+    ```
+    Activating the fistpoint `blktap_activate_inject_failure` mean that the VDI
+    activation will fail. This fistpoint always raise an exception but most
+    fistpoint just add a sleep at a point in the code.
+    Using the fixture `exit_on_fistpoint` make all fistpoints raise an
+    exception instead by enabling a special fistpoint called `fist_LVHDRT_exit`
+    """
+
     fistpointName: str
 
     def __init__(self, host: Host, name: str):

tests/storage/ext/test_ext_sr.py

@@ -2,6 +2,7 @@
 
 import logging
 
+from lib.commands import SSHCommandFailed
 from lib.common import vm_image, wait_for
 from lib.fistpoint import FistPoint
 from lib.vdi import VDI
@@ -64,12 +65,9 @@ def test_snapshot(self, vm_on_ext_sr):
     def test_blktap_activate_failure(self, vm_on_ext_sr):
         from lib.fistpoint import FistPoint
         vm = vm_on_ext_sr
-        with FistPoint(vm.host, "blktap_activate_inject_failure"):
-            try:
-                vm.start()
-                vm.shutdown(force=True)
-            except Exception as e:
-                logging.info(f"Expected failure {e}")
+        with FistPoint(vm.host, "blktap_activate_inject_failure"), pytest.raises(SSHCommandFailed):
+            vm.start()
+            vm.shutdown(force=True)
 
     @pytest.mark.small_vm
     @pytest.mark.big_vm
@@ -94,7 +92,7 @@ def test_failing_resize(self, host, ext_sr, vm_on_ext_sr, exit_on_fistpoint):
         with FistPoint(vm.host, "LVHDRT_inflate_after_setSize"):
             try:
                 vdi.resize(new_size)
-            except:
+            except Exception:
                 logging.info(f"Launching SR scan for {ext_sr} after failure")
                 host.xe("sr-scan", {"uuid": ext_sr})
 

tests/storage/lvm/test_lvm_sr.py

@@ -86,7 +86,8 @@ def test_failing_resize_on_inflate_after_setSize(self, host, lvm_sr, vm_on_lvm_s
             host.xe("sr-scan", {"uuid": lvm_sr.uuid})
         except SSHCommandFailed as e:
             assert False, f"Failing to scan following a inflate error {e}"
-        assert not lvinflate in host.lvs(f"VG_XenStorage-{lvm_sr.uuid}"), "Inflate journal still exist following the scan"
+        assert lvinflate not in host.lvs(f"VG_XenStorage-{lvm_sr.uuid}"), \
+            "Inflate journal still exist following the scan"
 
     @pytest.mark.small_vm
     @pytest.mark.big_vm
@@ -116,7 +117,8 @@ def test_failing_resize_on_inflate_after_setSizePhys(self, host, lvm_sr, vm_on_l
             host.xe("sr-scan", {"uuid": lvm_sr.uuid})
         except SSHCommandFailed as e:
             assert False, f"Failing to scan following a inflate error {e}"
-        assert not lvinflate in host.lvs(f"VG_XenStorage-{lvm_sr.uuid}"), "Inflate journal still exist following the scan"
+        assert lvinflate not in host.lvs(f"VG_XenStorage-{lvm_sr.uuid}"), \
+            "Inflate journal still exist following the scan"
 
     # *** tests with reboots (longer tests).