1 files changed, 122 insertions, 0 deletions
diff --git a/src/pybind/mgr/dashboard/services/exception.py b/src/pybind/mgr/dashboard/services/exception.py
new file mode 100644
index 00000000..b5c0bd58
--- /dev/null
+++ b/src/pybind/mgr/dashboard/services/exception.py
@@ -0,0 +1,122 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import
+
+import json
+import sys
+from contextlib import contextmanager
+
+import cherrypy
+
+import rbd
+import rados
+
+from .. import logger
+from ..services.ceph_service import SendCommandError
+from ..exceptions import ViewCacheNoDataException, DashboardException
+from ..tools import wraps
+
+if sys.version_info < (3, 0):
+    # Monkey-patch a __call__ method into @contextmanager to make
+    # it compatible to Python 3
+
+    from contextlib import GeneratorContextManager  # pylint: disable=no-name-in-module
+
+    def init(self, *args):
+        if len(args) == 1:
+            self.gen = args[0]
+        elif len(args) == 3:
+            self.func, self.args, self.kwargs = args
+        else:
+            raise TypeError()
+
+    def enter(self):
+        if hasattr(self, 'func'):
+            self.gen = self.func(*self.args, **self.kwargs)
+        try:
+            return self.gen.next()
+        except StopIteration:
+            raise RuntimeError("generator didn't yield")
+
+    def call(self, f):
+        @wraps(f)
+        def wrapper(*args, **kwargs):
+            with self:
+                return f(*args, **kwargs)
+
+        return wrapper
+
+    GeneratorContextManager.__init__ = init
+    GeneratorContextManager.__enter__ = enter
+    GeneratorContextManager.__call__ = call
+
+    # pylint: disable=function-redefined
+    def contextmanager(func):
+
+        @wraps(func)
+        def helper(*args, **kwds):
+            return GeneratorContextManager(func, args, kwds)
+
+        return helper
+
+
+def serialize_dashboard_exception(e, include_http_status=False, task=None):
+    """
+    :type e: Exception
+    :param include_http_status: Used for Tasks, where the HTTP status code is not available.
+    """
+    from ..tools import ViewCache
+    if isinstance(e, ViewCacheNoDataException):
+        return {'status': ViewCache.VALUE_NONE, 'value': None}
+
+    out = dict(detail=str(e))
+    try:
+        out['code'] = e.code
+    except AttributeError:
+        pass
+    component = getattr(e, 'component', None)
+    out['component'] = component if component else None
+    if include_http_status:
+        out['status'] = getattr(e, 'status', 500)
+    if task:
+        out['task'] = dict(name=task.name, metadata=task.metadata)
+    return out
+
+
+def dashboard_exception_handler(handler, *args, **kwargs):
+    try:
+        with handle_rados_error(component=None):  # make the None controller the fallback.
+            return handler(*args, **kwargs)
+    # Don't catch cherrypy.* Exceptions.
+    except (ViewCacheNoDataException, DashboardException) as e:
+        logger.exception('dashboard_exception_handler')
+        cherrypy.response.headers['Content-Type'] = 'application/json'
+        cherrypy.response.status = getattr(e, 'status', 400)
+        return json.dumps(serialize_dashboard_exception(e)).encode('utf-8')
+
+
+@contextmanager
+def handle_rbd_error():
+    try:
+        yield
+    except rbd.OSError as e:
+        raise DashboardException(e, component='rbd')
+    except rbd.Error as e:
+        raise DashboardException(e, component='rbd', code=e.__class__.__name__)
+
+
+@contextmanager
+def handle_rados_error(component):
+    try:
+        yield
+    except rados.OSError as e:
+        raise DashboardException(e, component=component)
+    except rados.Error as e:
+        raise DashboardException(e, component=component, code=e.__class__.__name__)
+
+
+@contextmanager
+def handle_send_command_error(component):
+    try:
+        yield
+    except SendCommandError as e:
+        raise DashboardException(e, component=component)