multiple improvements to migration algo

pym/update/update.py

@@ -1610,7 +1610,7 @@ class Update(MethodsInterface):
                                    self.Reason.Updating):
                 raise UpdateError(_("Failed to find the server with appropriate updates"))
             elif actual_reason is self.Reason.LevelWrong:
-                self.clVars.Set("update.cl_update_use_migration_host", Variable.On)
+                self.set_migration_mode()
                 #TODO add translation
                 raise UpdateError(_("Failed to find the server with appropriate level of updates"))
             else:
@@ -1650,13 +1650,6 @@ class Update(MethodsInterface):
             if not binhost.valid:
                 raise UpdateError(
                     _("Current binhost {} is not valid").format(binhost_url))
-            #TODO migr
-            elif not self.is_binhost_level_valid(binhost):
-                self.clVars.Set("update.cl_update_use_migration_host", Variable.On)
-                #TODO translate
-                raise UpdateError(
-                    _("Current binhost {} has a wrong update level. Current level: {} Binhost level: {}").\
-                            format(binhost_url, self.clVars.Get("update.cl_update_level"), binhost.level, ))
             elif binhost.outdated:
                 raise UpdateError(
                     _("Current binhost {} is outdated").format(binhost_url))
@@ -1664,6 +1657,14 @@ class Update(MethodsInterface):
                 raise UpdateError(
                     _("Binary packages on the current binhost {} "
                       "are older than local").format(binhost_url))
+            elif not self.is_binhost_level_valid(binhost):
+                self.stashBinhost(binhost_url)
+                self.set_migration_mode(True)
+                
+                #TODO translate
+                raise UpdateError(
+                    _("Current binhost {} has a wrong update level. Current level: {} Binhost level: {}").\
+                            format(binhost_url, self.clVars.Get("update.cl_update_level"), binhost.level, ))
             
         if self.binhosts_data.gpg:
             packages_fn = self.clVars.Get('update.cl_update_package_cache')
@@ -1711,15 +1712,46 @@ class Update(MethodsInterface):
 
         self.endTask()
         return True
+
+    def set_migration_mode(self, val=True):
+        val_to_write = Variable.On if val else Variable.Off
+        self.clVars.Write("update.cl_update_use_migration_host", val_to_write, location="system")
     
     def set_migration_host(self):
         #TODO translate
         self.startTask(_("Setting up migration host"))
-        retval = []
         dv = self.clVars
         last_ts = dv.Get('cl_update_last_timestamp')
         binhost_list = dv.Get('cl_update_binhost_migration_list')
         level = self.clVars.Get('update.cl_update_level')
+        migration_host = None
+        migr_binhost_data = []
+        while level < 20: #TODO set a const var?  or just while true? 
+        
+            migration_host_candidate = self._choose_migration_host(level, binhost_list, last_ts)
+            if not migration_host_candidate:
+                break
+            elif migration_host_candidate.downgraded:
+                self._update_increment_current_level()
+                level += 1
+            else:
+                migration_host = migration_host_candidate
+                break
+
+        if migration_host:
+            migr_binhost_data = [migration_host.host, migration_host.data,
+                    str(migration_host.timestamp),
+                    str(migration_host.duration)]
+        self.clVars.Set('update.cl_update_binhost_data',
+            migr_binhost_data or Variable.EmptyTable, force=True)
+        if not migr_binhost_data:
+            #TODO translate
+            raise UpdateError(_("Failed to find the working migration server with appropriate level"))
+        self.endTask()
+        return True
+
+    def _choose_migration_host(self, level, binhost_list, last_ts):
+        dv = self.clVars
         binhost_list = [self.get_migration_mirror_url(x, level) for x in binhost_list]
         binhosts_data = Binhosts(
             dv.GetInteger('cl_update_binhost_timeout'),
@@ -1728,15 +1760,9 @@ class Update(MethodsInterface):
             last_ts, binhost_list,
             self.get_arch_machine(),
             gpg=dv.Get('update.cl_update_gpg'))
-        migration_host = sorted(binhosts_data.get_binhosts(), reverse=True)[0]
-        retval.append([migration_host.host, migration_host.data,
-                            str(migration_host.timestamp),
-                            str(migration_host.duration)])
-        self.clVars.Set('update.cl_update_binhost_data',
-            retval or Variable.EmptyTable, force=True)
+        return sorted(binhosts_data.get_binhosts(), reverse=True)[0]
 
-        self.endTask()
-        return True
+                        
         
 
     def update_rep_list(self):
@@ -1828,11 +1854,28 @@ class Update(MethodsInterface):
     def update_increment_current_level(self):
         #TODO add translation
         self.startTask(_("Increasing update level"))
+        self._update_increment_current_level()
+        self.set_migration_mode(False)
+        self.delete_binhost()
+        self.endTask()
+        return True
+
+    def _update_increment_current_level(self):
         current_level = int(self.clVars.Get('cl_update_level'))
         self.clVars.Write('cl_update_level', 
                 str(current_level + 1), location="system")
-        self.clVars.Set("update.cl_update_use_migration_host",
-                Variable.Off)
-        self.delete_binhost()
-        self.endTask()
-        return True
+
+    def stashBinhost(self, binhost_url):
+        """
+        Бекап адреса бинхоста
+        """
+        self.clVars.Write("update.cl_update_binhost_stash", binhost_url, location="system")
+
+    def unstashBinhost(self):
+        """
+        Восстановление сохраненного бинхоста (если он есть)
+        """
+        val_to_write = self.clVars.Get("update.cl_update_binhost_stash")
+        if val_to_write:
+            self.clVars.Write('cl_update_binhost', val_to_write, location="system")
+    

pym/update/variables/update.py

@@ -1867,6 +1867,18 @@ class VariableClUpdateUseMigrationHost(Variable):
     type = "bool"
     value = "off"
 
+class VariableClUpdateMigrationHost(Variable):
+    """
+    Используемый хост миграции
+    """
+    value = ""
+
+class VariableClBinhostStash(Variable):
+    """
+    Бекап хоста обновления
+    """
+    value = ""
+
 class VariableClCheckUpdateLevel(Variable):
     """
     Проверять уровень обновления 

setup.py

@@ -18,7 +18,7 @@
 #  limitations under the License.
 
 __app__ = "calculate-update"
-__version__ = "3.2.2"
+__version__ = "3.2.2" #TODO bump version
 
 import os
 from glob import glob