test: catch correct exception in memory.py

The access to the `firecracker_pid` property causes a read to the vm's
pid file. This means that in the scenario where the VM is already dead
by the time the monitor starts running, we won't get a `NoSuchProcess`
error, we potentially get a `FileNotFoundError` (if the jail is already
cleaned up). Thus, to avoid spurious failures, also catch
`FileNotFoundError`.

We leave the catch for `NoSuchProcess` error in case a VM exits between
reading the pid file and the call to the`psutils.Process` constructor
(race condition).

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

tests/host_tools/memory.py

@@ -62,7 +62,7 @@ def run(self):
         guest_mem_bytes = self._vm.mem_size_bytes
         try:
             ps = psutil.Process(self._vm.firecracker_pid)
-        except psutil.NoSuchProcess:
+        except (psutil.NoSuchProcess, FileNotFoundError):
             return
         while not self._should_stop:
             try: