CDB-2999 Required files for running migration

NEWS.md

@@ -1,9 +1,14 @@
 2.14.1 (XXXX-XX-XX)
 -------------------
 * New features
+    * Upgraded UPGRADE doc and required rakes to run
+    * Added new rake: populate_new_fields
+    * Added user_id to Visualization Model
 
 * Fixed bugs
 
+* Migration Type (see UPGRADE): Mandatory migration
+
 
 2.14.0 (2014-05-20)
 -------------------

UPGRADE

@@ -1,20 +1,26 @@
-There's no standard procedure to migrate from one version to another of
-the rails application, so version specific procedures are documented
-in the NEWS.md file.
 
-In absence of specific instructions, after upgrading the rails code to
-<version>, you must upgrade existing databases using these commands:
+NOTES:
+ - Redis server must be listening on the configured
+   port (see config/app_config.yml) for some of the
+   steps below to work
+ - Rails must be restarted after an upgrade
+
+
+Standard migration (default)
+----------------------------
+
+Unless stated otherwise, assume any new CartoDB release requires calling these commands:
 
  $ bundle exec rake db:migrate
- $ bundle exec rake cartodb:db:load_functions
- $ bundle exec rake cartodb:db:load_triggers
- $ bundle exec rake cartodb:db:create_schemas
- $ bundle exec rake cartodb:db:migrate_to[<version>]
 
-NOTE: redis server must be listening on the configured 
-      port (see config/app_config.yml) for some of the
-      steps above to work
 
-Rails must be restarted after an upgrade
+Mandatory migration
+-------------------
 
+Versions marked at the NEWS.md as requiring this migration must run all this commands:
 
+ $ bundle exec rake db:migrate
+ $ bundle exec rake cartodb:db:populate_new_fields
+ $ bundle exec rake cartodb:db:load_functions
+ $ bundle exec rake cartodb:db:load_triggers
+ $ bundle exec rake cartodb:db:create_schemas

db/migrate/20140516125339_add_user_id_to_visualizations.rb

@@ -0,0 +1,9 @@
+Sequel.migration do
+  up do
+    add_column :visualizations, :user_id, :uuid
+  end
+
+  down do
+    drop_column :visualizations, :user_id
+  end
+end

lib/tasks/db_maintenance.rake

@@ -412,5 +412,39 @@ namespace :cartodb do
       end
     end
 
+    # New UPGRADE step, whose purpose is populate fields added by Rails migrations.
+    # Motivation: some field populations can be error-prone, time consuming, etc.,
+    # so better to leave each the responsability of try-catching or not.
+    # Initially it'd be nice if all populations are done via pure SQL queries,
+    # so this rake can be called in a branch that still has no Model changes
+    # and doesn't breaks the application
+    desc 'populates db new fields after certain migrations'
+    task :populate_new_fields => :environment do
+      # 2.14.1
+      execute_on_users_with_index(:populate_new_fields.to_s, Proc.new { |user, i|
+        user.db.execute(%Q{
+          UPDATE visualizations
+          SET user_id = maps.user_id FROM maps
+          WHERE maps.user_id='#{user.id}'
+          AND visualizations.user_id IS NULL
+          AND visualizations.map_id = maps.id
+         })
+      })
+
+    end #populate_new_fields
+
+    # Executes a ruby code proc/block on all existing users, outputting some info
+    # @param task_name string
+    # @param block Proc
+    def execute_on_users_with_index(task_name, block)
+      count = User.count
+      puts "Running #{task_name} for #{count} users"
+      User.all.each_with_index do |user, i|
+        puts "#{user.id} #{i}"
+        block.call(user, i)
+      end
+      puts "Finished #{task_name}"
+    end #execute_on_users_with_index
+
   end
 end