IBP: improve exception handling in fuel-agent

This patch resolves the issue with exception's message carrying and
adds very high level try/except clause to fuel-agent entrypoint.

Closes-Bug: #1422448
Change-Id: Ie0d326b3b5db4ce05e688a63b817971b4fd77080

fuel_agent/cmd/agent.py

@@ -16,6 +16,7 @@ import json
 import sys
 
 from oslo.config import cfg
+import six
 
 from fuel_agent import manager as manager
 from fuel_agent.openstack.common import log
@@ -31,6 +32,10 @@ opts = [
 
 CONF = cfg.CONF
 CONF.register_opts(opts)
+CONF(sys.argv[1:], project='fuel-agent',
+     version=version.version_info.release_string())
+log.setup('fuel-agent')
+LOG = log.getLogger(__name__)
 
 
 def provision():
@@ -53,18 +58,29 @@ def bootloader():
     main(['do_parsing', 'do_bootloader'])
 
 
+def print_err(line):
+    sys.stderr.write(six.text_type(line))
+    sys.stderr.write('\n')
+
+
+def handle_exception(exc):
+    LOG.exception(exc)
+    print_err('Unexpected error')
+    print_err(exc)
+    sys.exit(-1)
+
+
 def main(actions=None):
-    CONF(sys.argv[1:], project='fuel-agent',
-         version=version.version_info.release_string())
-    log.setup('fuel-agent')
+    try:
+        with open(CONF.provision_data_file) as f:
+            data = json.load(f)
 
-    with open(CONF.provision_data_file) as f:
-        data = json.load(f)
-
-    mgr = manager.Manager(data)
-    if actions:
-        for action in actions:
-            getattr(mgr, action)()
+        mgr = manager.Manager(data)
+        if actions:
+            for action in actions:
+                getattr(mgr, action)()
+    except Exception as exc:
+        handle_exception(exc)
 
 if __name__ == '__main__':
     main()

fuel_agent/drivers/ks_spaces_validator.py

@@ -15,6 +15,9 @@
 import jsonschema
 
 from fuel_agent import errors
+from fuel_agent.openstack.common import log as logging
+
+LOG = logging.getLogger(__name__)
 
 
 KS_SPACES_SCHEMA = {
@@ -128,6 +131,7 @@ def validate(scheme):
         jsonschema.validate(scheme, KS_SPACES_SCHEMA,
                             format_checker=checker)
     except Exception as exc:
+        LOG.exception(exc)
         raise errors.WrongPartitionSchemeError(str(exc))
 
     # scheme is not valid if the number of disks is 0

fuel_agent/errors.py

@@ -12,15 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from fuel_agent.openstack.common import log as logging
-
-LOG = logging.getLogger(__name__)
-
 
 class BaseError(Exception):
-    def __init__(self, *args, **kwargs):
-        super(BaseException, self).__init__(*args, **kwargs)
-        LOG.error(self.message)
+    def __init__(self, message, *args, **kwargs):
+        self.message = message
+        super(BaseError, self).__init__(message, *args, **kwargs)
 
 
 class WrongPartitionSchemeError(BaseError):
@@ -103,7 +99,7 @@ class TemplateWriteError(BaseError):
     pass
 
 
-class ProcessExecutionError(Exception):
+class ProcessExecutionError(BaseError):
     def __init__(self, stdout=None, stderr=None, exit_code=None, cmd=None,
                  description=None):
         self.exit_code = exit_code

fuel_agent/utils/md_utils.py

@@ -61,7 +61,8 @@ def mddisplay(names=None):
             output = utils.execute('mdadm', '--detail', mdname,
                                    check_exit_code=[0])[0]
             md.update(mddetail_parse(output))
-        except errors.ProcessExecutionError:
+        except errors.ProcessExecutionError as exc:
+            LOG.debug(exc)
             continue
         finally:
             mds.append(md)