Begin writing migration from mongo to mysql

lib/mongo_to_mysql.rb

+#   Copyright (c) 2010, Diaspora Inc.  This file is
+#   licensed under the Affero General Public License version 3 or later.  See
+#   the COPYRIGHT file.
+
+class MongoToMysql
+  def id_sed
+    @id_sed = sed_replace('{\ \"$oid\"\ :\ \(\"[^"]*\"\)\ }')
+  end
+  def date_sed
+    @date_sed = sed_replace('{\ \"$date\"\ :\ \([0-9]*\)\ }')
+  end
+  def sed_replace(regex)
+    "sed 's/#{regex}/\\1/g'"
+  end
+end

lib/tasks/migrations.rake

+#   Copyright (c) 2010, Diaspora Inc.  This file is
+#   licensed under the Affero General Public License version 3 or later.  See
+#   the COPYRIGHT file.
+
+require File.join(Rails.root, 'lib/rake_helpers')
+include RakeHelpers
+
+namespace :migrations do
+  desc 'export data for mysql import'
+  task :export_for_mysql do
+    require 'lib/mongo_to_mysql'
+    migrator = MongoToMysql.new
+    db_name = "diaspora-development"
+    models = [
+      :aspects,
+      :comments,
+      :contacts,
+      :invitations,
+      :notifications,
+      :people,
+      :posts,
+      :requests,
+      :users,
+    ]
+    `mkdir -p #{Rails.root}/tmp/export-for-mysql`
+    models.each do |model|
+      filename = "#{Rails.root}/tmp/export-for-mysql/#{model}.json"
+      `mongoexport -d #{db_name} -c #{model} | #{migrator.id_sed} | #{migrator.date_sed} > #{filename}`
+      puts "#{model} exported to #{filename}"
+      #`mongoexport -d #{db_name} -c #{model} -jsonArray | sed 's/\"[^"]*\"/"IAMID"/g' > #{filename}`
+    end
+  end
+end