Merge lp:~javier.collado/utah/install_sigterm_handler into lp:utah

[Javier Collado]

The changes in this branch add a handler for SIGTERM that just raises an
exception. This is intended to terminate the process gracefully and call all
the cleanup callbacks in the Machine object.

On one hand, I've verified that jenkins sends the SIGTERM signal when a job is
cancelled in the we interface. On the other hand, I've tested this
specificially with `run_test_cobbler.py` to make sure that the image is
unmounted and the loop device freed when the SIGTERM signal is received.

[Andy Doan (doanac)]

nice - all the changes to the run_*.py's are annoying. Could we do that from run.py safely, or is this best for now until we have a better way of managing these different script variations?

[Javier Collado (javier.collado)]

I agree on that all that duplication is annoying. `install_sigterm_handler` is
already in `run.py` and is only a function call in all the scripts that we use
to run test cases.

One way I can think of to improve the situation would be to refactor both the
logging configuration and this into a single function that could be used to
perform common setup. However, we'd still have the problem of having multiple
entry points and calling something multiple times. Hence, in my opinion, the
real solution would be to refactor all the scripts we have into a single one
and really have a single entry point. Please, let me know your thoughs on this.

[Andy Doan (doanac)]

On 02/14/2013 12:24 PM, Javier Collado wrote:
> Hence, in my opinion, the
> real solution would be to refactor all the scripts we have into a single one
> and really have a single entry point. Please, let me know your thoughs on this.

yeah, I read the code a bit after my original response and came to the
same conclusion.

[Max Brustkern (nuclearbob)]

I've got two thoughts that don't require action.

It looks like install_sigterm_handler is always called right before run_tests. Any thoughts about moving it into there?

Also, some of the imports are not in alphabetical order. That doesn't matter at all, but if I'm working in those files in the future, I'll probably change it, because I'm a little weird about that. :)

[lp:~javier.collado/utah/install_sigterm_handler]

819. By Javier Collado on 2013-02-15

Moved install_sigterm_handler to run_tests

[Javier Collado (javier.collado)]

Max, I think your suggestion is a good one, so I've updated the changes
accordingly.

review: Needs Resubmitting

[Javier Collado (javier.collado)]

Regarding the imports ordering, it would be nice to have that in the coding
guidelines as well.

[Max Brustkern (nuclearbob)]

Good point about the coding guidelines. We can discuss that the next time we have a standup or other meeting. The changes look good to me.

review: Approve

=== modified file 'examples/run_test_vm.py'
--- examples/run_test_vm.py	2013-01-23 12:26:38 +0000
+++ examples/run_test_vm.py	2013-02-15 08:41:19 +0000
@@ -21,7 +21,11 @@
 from utah.exceptions import UTAHException
 from utah.group import check_user_group, print_group_error_message
 from utah.provisioning.vm.vm import TinySQLiteInventory
-from utah.run import common_arguments, run_tests, configure_logging
+from utah.run import (
+    common_arguments,
+    run_tests,
+    configure_logging,
+)
 
 
 def get_parser():

=== modified file 'examples/run_utah_tests.py'
--- examples/run_utah_tests.py	2013-02-05 16:36:34 +0000
+++ examples/run_utah_tests.py	2013-02-15 08:41:19 +0000
@@ -27,7 +27,7 @@
     name_argument,
     virtual_arguments,
     configure_logging,
-    run_tests
+    run_tests,
 )
 from utah.timeout import timeout, UTAHTimeout
 from run_install_test import run_install_test

=== modified file 'utah/run.py'
--- utah/run.py	2013-02-05 17:22:28 +0000
+++ utah/run.py	2013-02-15 08:41:19 +0000
@@ -22,6 +22,7 @@
 import urllib
 import traceback
 import shutil
+import signal
 
 from utah import config
 from utah.exceptions import UTAHException
@@ -112,6 +113,8 @@
     """
     Run some tests and retrieve results.
     """
+    install_sigterm_handler()
+
     if args.json:
         report_type = 'json'
     else:
@@ -291,3 +294,19 @@
     logger = logging.getLogger('paramiko')
     logger.propagate = False
     logger.addHandler(ssh_file_handler)
+
+
+def install_sigterm_handler():
+    """Capture SIGTERM signal to avoid abrupt process termination.
+
+    This function registers a handler that raises an exception when SIGTERM is
+    received to ensure that machine object cleanup methods are called.
+    Otherwise, cleanup methods aren't called when the process is abruptly
+    terminated.
+
+    """
+    def handler(signum, frame):
+        """Raise exception when signal is received."""
+        raise UTAHException('Signal received: {}'.format(signum))
+
+    signal.signal(signal.SIGTERM, handler)