Merge lp:~allenap/maas/pretty-error-message--bug-1412026 into lp:~maas-committers/maas/trunk

[Gavin Panella]

Provide an explanation for crashes in the image download service.

This helps prevent us from misdiagnosing tracebacks as critical crashes.

[Blake Rouse (blake-rouse)]

review: Approve

=== modified file 'src/provisioningserver/pserv_services/image_download_service.py'
--- src/provisioningserver/pserv_services/image_download_service.py	2015-03-25 15:33:23 +0000
+++ src/provisioningserver/pserv_services/image_download_service.py	2015-04-28 11:44:46 +0000
@@ -69,7 +69,7 @@
         the maas log.
         """
         def download_failure(failure):
-            log.err(failure)
+            log.err(failure, "Downloading images failed.")
             maaslog.error(
                 "Failed to download images: %s", failure.getErrorMessage())
 
 
=== modified file 'src/provisioningserver/pserv_services/tests/test_image_download_service.py'
--- src/provisioningserver/pserv_services/tests/test_image_download_service.py	2015-03-25 15:33:23 +0000
+++ src/provisioningserver/pserv_services/tests/test_image_download_service.py	2015-04-28 11:44:46 +0000
@@ -185,7 +185,7 @@
         maybe_start_download.return_value = defer.fail(
             ZeroDivisionError("Such a shame I can't divide by zero"))
 
-        with FakeLogger("maas") as maaslog, TwistedLoggerFixture():
+        with FakeLogger("maas") as maaslog, TwistedLoggerFixture() as logger:
             d = service.try_download()
 
         self.assertEqual(None, extract_result(d))
@@ -193,6 +193,13 @@
             "Failed to download images: "
             "Such a shame I can't divide by zero",
             maaslog.output)
+        self.assertDocTestMatches(
+            """\
+            Downloading images failed.
+            Traceback (most recent call last):
+            Failure: exceptions.ZeroDivisionError: Such a shame ...
+            """,
+            logger.output)
 
 
 class TestGetBootSources(PservTestCase):