[Kimchi-devel] [PATCH V4 5/6] Fix 'disk full' issue: Fix vms/screenshot db store/delete error handling

[Rodrigo Trujillo]

When creating, running or deleting a vm, it uses the database to store
vm and screenshot information. If the disk is full, Kimchi will raise
errors constantly and UI will be useless. This patch fixes this problem,
omitting from UI and logging in the backend. So, user is still able to
create, start and stop a vm.

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
---
 src/kimchi/model/vms.py | 70 +++++++++++++++++++++++++++++++++++--------------
 1 file changed, 50 insertions(+), 20 deletions(-)

diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
index c8dfc90..12e780b 100644
--- a/src/kimchi/model/vms.py
+++ b/src/kimchi/model/vms.py
@@ -34,6 +34,7 @@ from kimchi.model.config import CapabilitiesModel
 from kimchi.model.templates import TemplateModel
 from kimchi.model.utils import get_vm_name
 from kimchi.screenshot import VMScreenshot
+from kimchi.utils import kimchi_log
 from kimchi.utils import run_setfacl_set_attr, template_name_from_uri
 
 
@@ -176,6 +177,18 @@ class VMsModel(object):
 
         t.validate()
 
+        # Store the icon for displaying later
+        icon = t.info.get('icon')
+        if icon:
+            try:
+                with self.objstore as session:
+                    session.store('vm', vm_uuid, {'icon': icon})
+            except Exception as e:
+                # It is possible to continue Kimchi executions without store
+                # vm icon info
+                kimchi_log.error('Error trying to update database with guest '
+                    'icon information due error: %s', e.message)
+
         # If storagepool is SCSI, volumes will be LUNs and must be passed by
         # the user from UI or manually.
         vol_list = []
@@ -184,12 +197,6 @@ class VMsModel(object):
         else:
             vol_list = t.fork_vm_storage(vm_uuid)
 
-        # Store the icon for displaying later
-        icon = t.info.get('icon')
-        if icon:
-            with self.objstore as session:
-                session.store('vm', vm_uuid, {'icon': icon})
-
         graphics = params.get('graphics')
         stream_protocols = self.caps.libvirt_stream_protocols
         xml = t.to_vm_xml(name, vm_uuid,
@@ -350,9 +357,13 @@ class VMModel(object):
             pool_type = xmlutils.xpath_get_text(xml, "/pool/@type")[0]
             if pool_type not in READONLY_POOL_TYPE:
                 vol.delete(0)
-
-        with self.objstore as session:
-            session.delete('vm', dom.UUIDString(), ignore_missing=True)
+        try:
+            with self.objstore as session:
+                session.delete('vm', dom.UUIDString(), ignore_missing=True)
+        except Exception as e:
+            # It is possible to delete vm without delete its database info
+            kimchi_log.error('Error deleting vm information from database: '
+                             '%s', e.message)
 
         vnc.remove_proxy_token(name)
 
@@ -408,9 +419,14 @@ class VMModel(object):
         screenshot = VMScreenshotModel.get_screenshot(vm_uuid, self.objstore,
                                                       self.conn)
         screenshot.delete()
-        with self.objstore as session:
-            session.delete('screenshot', vm_uuid)
-
+        try:
+            with self.objstore as session:
+                session.delete('screenshot', vm_uuid)
+        except Exception as e:
+            # It is possible to continue Kimchi executions without delete
+            # screenshots
+            kimchi_log.error('Error trying to delete vm screenshot from '
+                'database due error: %s', e.message)
 
 class VMScreenshotModel(object):
     def __init__(self, **kargs):
@@ -427,18 +443,32 @@ class VMScreenshotModel(object):
         screenshot = self.get_screenshot(vm_uuid, self.objstore, self.conn)
         img_path = screenshot.lookup()
         # screenshot info changed after scratch generation
-        with self.objstore as session:
-            session.store('screenshot', vm_uuid, screenshot.info)
+        try:
+            with self.objstore as session:
+                session.store('screenshot', vm_uuid, screenshot.info)
+        except Exception as e:
+            # It is possible to continue Kimchi executions without store
+            # screenshots
+            kimchi_log.error('Error trying to update database with guest '
+                'screenshot information due error: %s', e.message)
         return img_path
 
     @staticmethod
     def get_screenshot(vm_uuid, objstore, conn):
-        with objstore as session:
-            try:
-                params = session.get('screenshot', vm_uuid)
-            except NotFoundError:
-                params = {'uuid': vm_uuid}
-                session.store('screenshot', vm_uuid, params)
+        try:
+            with objstore as session:
+                try:
+                    params = session.get('screenshot', vm_uuid)
+                except NotFoundError:
+                    params = {'uuid': vm_uuid}
+                    session.store('screenshot', vm_uuid, params)
+        except Exception as e:
+            # The 'except' outside of 'with' is necessary to catch possible
+            # exception from '__exit__' when calling 'session.store'
+            # It is possible to continue Kimchi vm executions without
+            # screenshots
+            kimchi_log.error('Error trying to update database with guest '
+                'screenshot information due error: %s', e.message)
         return LibvirtVMScreenshot(params, conn)
 
 
-- 
1.8.5.3