test: Modernize test_send_ctrl_alt_del

Instead of sleeping for 2 seconds to wait for booting, add a network
device and wait for ssh availability (happens automatically in
.start()). Use mark_killed() to assert that Firecracker exited instead
of the homegrown "waitpid" solution (which I'm pretty sure didn't work,
because this test would have always failed during microvm teardown
otherwise, since it never set _killed to True).

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

Author: roypat

tests/integration_tests/functional/test_api.py

@@ -779,24 +779,14 @@ def test_send_ctrl_alt_del(uvm_plain):
     test_microvm.spawn()
 
     test_microvm.basic_config()
+    test_microvm.add_net_iface()
     test_microvm.start()
 
-    # Wait around for the guest to boot up and initialize the user space
-    time.sleep(2)
-
     test_microvm.api.actions.put(action_type="SendCtrlAltDel")
 
-    firecracker_pid = test_microvm.firecracker_pid
-
     # If everything goes as expected, the guest OS will issue a reboot,
     # causing Firecracker to exit.
-    # waitpid should block until the Firecracker process has exited. If
-    # it has already exited by the time we call waitpid, WNOHANG causes
-    # waitpid to raise a ChildProcessError exception.
-    try:
-        os.waitpid(firecracker_pid, os.WNOHANG)
-    except ChildProcessError:
-        pass
+    test_microvm.mark_killed()
 
 
 def _drive_patch(test_microvm):