slapos_cloud: Include entry point to customise allocation decision

This helps to introduce some scripting for allocation algorithm for specialise certain nodes.

This change was originally introduce by Alain Takoudjou.

master/bt5/slapos_cloud/SkinTemplateItem/portal_skins/slapos_cloud/ComputerPartition_getCustomAllocationParameterDict.xml

+<?xml version="1.0"?>
+<ZopeData>
+  <record id="1" aka="AAAAAAAAAAE=">
+    <pickle>
+      <global name="PythonScript" module="Products.PythonScripts.PythonScript"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>Script_magic</string> </key>
+            <value> <int>3</int> </value>
+        </item>
+        <item>
+            <key> <string>_bind_names</string> </key>
+            <value>
+              <object>
+                <klass>
+                  <global name="NameAssignments" module="Shared.DC.Scripts.Bindings"/>
+                </klass>
+                <tuple/>
+                <state>
+                  <dictionary>
+                    <item>
+                        <key> <string>_asgns</string> </key>
+                        <value>
+                          <dictionary>
+                            <item>
+                                <key> <string>name_container</string> </key>
+                                <value> <string>container</string> </value>
+                            </item>
+                            <item>
+                                <key> <string>name_context</string> </key>
+                                <value> <string>context</string> </value>
+                            </item>
+                            <item>
+                                <key> <string>name_m_self</string> </key>
+                                <value> <string>script</string> </value>
+                            </item>
+                            <item>
+                                <key> <string>name_subpath</string> </key>
+                                <value> <string>traverse_subpath</string> </value>
+                            </item>
+                          </dictionary>
+                        </value>
+                    </item>
+                  </dictionary>
+                </state>
+              </object>
+            </value>
+        </item>
+        <item>
+            <key> <string>_body</string> </key>
+            <value> <string>query_kw = dict()\n
+\n
+return query_kw\n
+</string> </value>
+        </item>
+        <item>
+            <key> <string>_params</string> </key>
+            <value> <string>software_release_url, software_type, software_instance_portal_type, filter_kw, computer_network_query=None, test_mode=False</string> </value>
+        </item>
+        <item>
+            <key> <string>id</string> </key>
+            <value> <string>ComputerPartition_getCustomAllocationParameterDict</string> </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+</ZopeData>

master/bt5/slapos_cloud/SkinTemplateItem/portal_skins/slapos_cloud/Person_findPartition.xml

@@ -57,6 +57,7 @@ from Products.ZSQLCatalog.SQLCatalog import SimpleQuery, ComplexQuery\n
 person = context\n
 \n
 computer_partition = None\n
+filter_kw_copy = filter_kw.copy()\n
 query_kw = {\n
   \'software_release_url\': software_release_url,\n
   \'portal_type\': \'Computer Partition\',\n
@@ -128,6 +129,12 @@ query_kw["capacity_scope_uid"] = context.getPortalObject().portal_categories.cap
 #   # Only allocation on public computer\n
 #   query_kw["allocation_scope_uid"] = context.getPortalObject().portal_categories.allocation_scope.open.public.getUid()\n
 \n
+extra_query_kw = context.ComputerPartition_getCustomAllocationParameterDict(\n
+      software_release_url, software_type, software_instance_portal_type,\n
+      filter_kw_copy, computer_network_query, test_mode)\n
+if extra_query_kw:\n
+  query_kw.update(extra_query_kw)\n
+\n
 if filter_kw.keys():\n
   # XXX Drop all unexpected keys\n
   query_kw["uid"] = "-1"\n