Bug fixes and important missing features for standalone / testcase

The most important are:
 * sometimes instance was not properly destroyed, apparently we need to retry `slapos node report`
 * if instance is not properly destroy, remove the files ourself and mark test failed
 * we need to see log files and config files from the instance

there's also a few small commits not directly related.

/reviewed-on nexedi/slapos.core!145

slapos/slap/standalone.py

@@ -50,6 +50,7 @@ import psutil
 from .interface.slap import IException
 from .interface.slap import ISupply
 from .interface.slap import IRequester
+from ..grid.slapgrid import SLAPGRID_PROMISE_FAIL
 
 from .slap import slap
 from ..grid.svcbackend import getSupervisorRPC
@@ -60,10 +61,12 @@ class SlapOSNodeCommandError(Exception):
   """Exception raised when running a SlapOS Node command failed.
   """
   def __str__(self):
+    # This is a false positive in pylint https://github.com/PyCQA/pylint/issues/1498
+    called_process_error = self.args[0] #  pylint: disable=unsubscriptable-object
     return "{} exitstatus: {} output:\n{}".format(
         self.__class__.__name__,
-        self.args[0]['exitstatus'],
-        self.args[0]['output'],
+        called_process_error['exitstatus'],
+        called_process_error['output'],
     )
 
 
@@ -471,7 +474,19 @@ class StandaloneSlapOS(object):
     for part in unknown_partition_set:
       self._logger.debug(
           "removing partition no longer part of format spec %s", part)
+      # remove partition directory
       shutil.rmtree(part)
+      # remove partition supervisor config, if it was not removed cleanly
+      supervisor_conf = os.path.join(
+          self._instance_root,
+          'etc',
+          'supervisord.conf.d',
+          '%s.conf' % os.path.basename(part))
+      if os.path.exists(supervisor_conf):
+        self._logger.info(
+          "removing leftover supervisor config from destroyed partition at %s",
+          supervisor_conf)
+        os.unlink(supervisor_conf)
 
   def supply(self, software_url, computer_guid=None, state="available"):
     """Supply a software, see ISupply.supply
@@ -630,9 +645,14 @@ class StandaloneSlapOS(object):
       prog = self._slapos_commands[command]
       # used in format(**locals()) below
       debug_args = prog.get('debug_args', '')  # pylint: disable=unused-variable
-      return subprocess.check_call(
-          prog['command'].format(**locals()), shell=True)
-
+      command = prog['command'].format(**locals())
+      try:
+        return subprocess.check_call(command, shell=True)
+      except subprocess.CalledProcessError as e:
+        if e.returncode == SLAPGRID_PROMISE_FAIL:
+          self._logger.exception('Promise error when running %s', command)
+          import pdb; pdb.post_mortem()
+        raise
     with self.system_supervisor_rpc as supervisor:
       retry = 0
       while True:

slapos/testing/testcase.py

@@ -30,6 +30,8 @@ import unittest
 import os
 import glob
 import logging
+import shutil
+from six.moves.urllib.parse import urlparse
 
 try:
   import subprocess32 as subprocess
@@ -43,6 +45,7 @@ from ..slap.standalone import StandaloneSlapOS
 from ..slap.standalone import SlapOSNodeCommandError
 from ..slap.standalone import PathTooDeepError
 from ..grid.utils import md5digest
+from ..util import mkdir_p
 
 try:
   from typing import Iterable, Tuple, Callable, Type
@@ -59,6 +62,7 @@ def makeModuleSetUpAndTestCaseClass(
     verbose=bool(int(os.environ.get('SLAPOS_TEST_VERBOSE', 0))),
     shared_part_list=os.environ.get('SLAPOS_TEST_SHARED_PART_LIST',
                                     '').split(os.pathsep),
+    snapshot_directory=os.environ.get('SLAPOS_TEST_LOG_DIRECTORY')
 ):
   # type: (str, str, str, str, bool, bool, List[str]) -> Tuple[Callable[[], None], Type[SlapOSInstanceTestCase]]
   """Create a setup module function and a testcase for testing `software_url`.
@@ -116,16 +120,22 @@ def makeModuleSetUpAndTestCaseClass(
         'base directory ( {} ) is too deep, try setting '
         'SLAPOS_TEST_WORKING_DIR to a shallow enough directory'.format(
             base_directory))
+  if not snapshot_directory:
+    snapshot_directory = os.path.join(base_directory, "snapshots")
+
 
   cls = type(
       'SlapOSInstanceTestCase for {}'.format(software_url),
       (SlapOSInstanceTestCase,), {
           'slap': slap,
           'getSoftwareURL': classmethod(lambda _cls: software_url),
+          'software_id': urlparse(software_url).path.split('/')[-2],
           '_debug': debug,
           '_verbose': verbose,
           '_ipv4_address': ipv4_address,
-          '_ipv6_address': ipv6_address
+          '_ipv6_address': ipv6_address,
+          '_base_directory': base_directory,
+          '_test_file_snapshot_directory': snapshot_directory
       })
 
   class SlapOSInstanceTestCase_(cls, SlapOSInstanceTestCase):
@@ -136,8 +146,8 @@ def makeModuleSetUpAndTestCaseClass(
     # type: () -> None
     if debug:
       unittest.installHandler()
-    if verbose or debug:
-      logging.basicConfig(level=logging.DEBUG)
+    logging.basicConfig(
+        level=logging.DEBUG if (verbose or debug) else logging.WARNING)
     installSoftwareUrlList(cls, [software_url], debug=debug)
 
   return setUpModule, SlapOSInstanceTestCase_
@@ -260,7 +270,7 @@ class SlapOSInstanceTestCase(unittest.TestCase):
   # maximum retries for `slapos node instance`
   instance_max_retry = 10
   # maximum retries for `slapos node report`
-  report_max_retry = 0
+  report_max_retry = 2
   # number of partitions needed for this instance
   partition_count = 10
   # reference of the default requested partition
@@ -274,6 +284,19 @@ class SlapOSInstanceTestCase(unittest.TestCase):
   _ipv4_address = ""
   _ipv6_address = ""
 
+  # a short name of that software URL.
+  # eg. helloworld instead of
+  # https://lab.nexedi.com/nexedi/slapos/raw/software/helloworld/software.cfg
+  software_id = ""
+  _base_directory = ""  # base directory for standalone
+  _test_file_snapshot_directory = ""  # directory to save snapshot files for inspections
+  # patterns of files to save for inspection, relative to instance directory
+  _save_instance_file_pattern_list = (
+      '*/etc/*',
+      '*/var/log/*',
+      '*/.*log',
+  )
+
   # Methods to be defined by subclasses.
   @classmethod
   def getSoftwareURL(cls):
@@ -361,6 +384,42 @@ class SlapOSInstanceTestCase(unittest.TestCase):
     """
     cls._cleanup()
 
+  def tearDown(self):
+    # copy log files from standalone
+    for standalone_log in glob.glob(os.path.join(
+          self._base_directory, 'var', 'log', '*')):
+      self._snapshot_instance_file(standalone_log)
+
+    # copy config and log files from partitions
+    for pattern in self._save_instance_file_pattern_list:
+      for f in glob.glob(os.path.join(self.slap.instance_directory, pattern)):
+        self._snapshot_instance_file(f)
+
+  def _snapshot_instance_file(self, source_file_name):
+    """Save a file for later inspection.
+
+    The path are made relative to slapos root directory and
+    we keep the same directory structure.
+    """
+    # we cannot use os.path.commonpath on python2, so implement something similar
+    common_path = os.path.commonprefix((source_file_name, self._base_directory))
+    if not os.path.isdir(common_path):
+      common_path = os.path.dirname(common_path)
+
+    relative_path = source_file_name[len(common_path):]
+    if relative_path[0] == os.sep:
+      relative_path = relative_path[1:]
+    destination = os.path.join(
+        self._test_file_snapshot_directory,
+        self.software_id,
+        self.id(),
+        relative_path)
+    destination_dirname = os.path.dirname(destination)
+    mkdir_p(destination_dirname)
+    if os.path.isfile(source_file_name):
+      self.logger.debug("copy %s as %s", source_file_name, destination)
+      shutil.copy(source_file_name, destination)
+
   # implementation methods
   @classmethod
   def _cleanup(cls):
@@ -402,6 +461,11 @@ class SlapOSInstanceTestCase(unittest.TestCase):
       cls.slap.stop()
     except:
       cls.logger.exception("Error during stop")
+    leaked_supervisor_configs = glob.glob(
+        os.path.join(cls.slap.instance_directory, 'etc', 'supervisord.conf.d', '*.conf'))
+    if leaked_supervisor_configs:
+      [os.unlink(config) for config in leaked_supervisor_configs]
+      raise AssertionError("Test leaked supervisor configurations: %s" % leaked_supervisor_configs)
 
   @classmethod
   def requestDefaultInstance(cls, state='started'):