# HG changeset patch
# User Nattee Niparnan <nattee@gmail.com>
# Date 2022-01-15 14:03:59
# Node ID f42556ce3209615c23f59335029dd6625bb98fd8
# Parent  7ceba92b053f3da1eadcfeef64f859c2f32d5558

update migration

diff --git a/Gemfile.lock b/Gemfile.lock
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -370,4 +370,4 @@
    ruby 3.1.0p0
 
 BUNDLED WITH
-   2.3.5
+   2.3.3
diff --git a/README.rdoc b/README.rdoc
--- a/README.rdoc
+++ b/README.rdoc
@@ -53,9 +53,19 @@
 1. You have to reboot since RVM change a lots of system.
 2. If you are using GUI version of Ubuntu, be sure to have Gnome Terminal (or any other terminal you are using) perform login every time. This can be done by mark the check box "Run command as a login shell" in Gnome terminal or by adding --login to bash. 
 
-=== 3. Install necessary package
+=== 3. Install necessary package and nodejs
+
+First, we install required package via apt.
+
+    cafe@grader:~$ sudo apt install libmysqlclient-dev default-jdk unzip php-cli apache2 dirmngr gnupg apache2-dev
 
-    cafe@grader:~$ sudo apt install libmysqlclient-dev default-jdk unzip nodejs php-cli apache2 dirmngr gnupg apache2-dev
+Since nodejs that comes with ubuntu 18.04 is very outdated, we need to install it manually. This follow the method outlined in https://www.digitalocean.com/community/tutorials/how-to-install-node-js-on-ubuntu-18-04 under *Installing Node.js with Apt Using a NodeSource PPA*
+
+    cd ~
+    curl -sL https://deb.nodesource.com/setup_17.x -o nodesource_setup.sh
+    sudo bash nodesource_setup.sh
+    sudo apt install nodejs
+
 
 === 4. Install cafe-grader
 
diff --git a/db/migrate/001_create_users.rb b/db/migrate/001_create_users.rb
--- a/db/migrate/001_create_users.rb
+++ b/db/migrate/001_create_users.rb
@@ -1,6 +1,6 @@
-class CreateUsers < ActiveRecord::Migration
+class CreateUsers < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :users do |t|
+    create_table :users, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :login, :string, :limit => 10
       t.column :full_name, :string
       t.column :hashed_password, :string
diff --git a/db/migrate/002_create_problems.rb b/db/migrate/002_create_problems.rb
--- a/db/migrate/002_create_problems.rb
+++ b/db/migrate/002_create_problems.rb
@@ -1,6 +1,6 @@
-class CreateProblems < ActiveRecord::Migration
+class CreateProblems < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :problems do |t|
+    create_table :problems, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :name, :string, :limit => 30
       t.column :full_name, :string
       t.column :full_score, :integer
diff --git a/db/migrate/003_create_submissions.rb b/db/migrate/003_create_submissions.rb
--- a/db/migrate/003_create_submissions.rb
+++ b/db/migrate/003_create_submissions.rb
@@ -1,6 +1,6 @@
-class CreateSubmissions < ActiveRecord::Migration
+class CreateSubmissions < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :submissions do |t|
+    create_table :submissions, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :user_id, :integer
       t.column :problem_id, :integer
       t.column :language_id, :integer
diff --git a/db/migrate/004_create_languages.rb b/db/migrate/004_create_languages.rb
--- a/db/migrate/004_create_languages.rb
+++ b/db/migrate/004_create_languages.rb
@@ -1,6 +1,6 @@
-class CreateLanguages < ActiveRecord::Migration
+class CreateLanguages < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :languages do |t|
+    create_table :languages, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :name, :string, :limit => 10
       t.column :pretty_name, :string
     end
diff --git a/db/migrate/005_add_index_to_submissions.rb b/db/migrate/005_add_index_to_submissions.rb
--- a/db/migrate/005_add_index_to_submissions.rb
+++ b/db/migrate/005_add_index_to_submissions.rb
@@ -1,4 +1,4 @@
-class AddIndexToSubmissions < ActiveRecord::Migration
+class AddIndexToSubmissions < ActiveRecord::Migration[4.2]
   def self.up
     add_index :submissions, [:user_id, :problem_id]
   end
diff --git a/db/migrate/006_create_roles.rb b/db/migrate/006_create_roles.rb
--- a/db/migrate/006_create_roles.rb
+++ b/db/migrate/006_create_roles.rb
@@ -1,10 +1,10 @@
-class CreateRoles < ActiveRecord::Migration
+class CreateRoles < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :roles do |t|
+    create_table :roles, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'name', :string
     end
 
-    create_table :roles_users, :id => false do |t|
+    create_table :roles_users, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'role_id', :integer
       t.column 'user_id', :integer
     end
diff --git a/db/migrate/007_create_rights.rb b/db/migrate/007_create_rights.rb
--- a/db/migrate/007_create_rights.rb
+++ b/db/migrate/007_create_rights.rb
@@ -1,12 +1,12 @@
-class CreateRights < ActiveRecord::Migration
+class CreateRights < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :rights do |t|
+    create_table :rights, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'name', :string
       t.column 'controller', :string
       t.column 'action', :string
     end
 
-    create_table :rights_roles, :id => false do |t|
+    create_table :rights_roles, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'right_id', :integer
       t.column 'role_id', :integer
     end
diff --git a/db/migrate/008_create_tasks.rb b/db/migrate/008_create_tasks.rb
--- a/db/migrate/008_create_tasks.rb
+++ b/db/migrate/008_create_tasks.rb
@@ -1,6 +1,6 @@
-class CreateTasks < ActiveRecord::Migration
+class CreateTasks < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :tasks do |t|
+    create_table :tasks, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'submission_id', :integer
       t.column 'created_at', :datetime
     end
diff --git a/db/migrate/009_add_sessions.rb b/db/migrate/009_add_sessions.rb
--- a/db/migrate/009_add_sessions.rb
+++ b/db/migrate/009_add_sessions.rb
@@ -1,6 +1,6 @@
-class AddSessions < ActiveRecord::Migration
+class AddSessions < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :sessions do |t|
+    create_table :sessions, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :session_id, :string
       t.column :data, :text
       t.column :updated_at, :datetime
diff --git a/db/migrate/011_add_language_ext.rb b/db/migrate/011_add_language_ext.rb
--- a/db/migrate/011_add_language_ext.rb
+++ b/db/migrate/011_add_language_ext.rb
@@ -1,4 +1,4 @@
-class AddLanguageExt < ActiveRecord::Migration
+class AddLanguageExt < ActiveRecord::Migration[4.2]
   def self.up
     add_column :languages, :ext, :string, :limit => 10
 
diff --git a/db/migrate/012_add_email_to_users.rb b/db/migrate/012_add_email_to_users.rb
--- a/db/migrate/012_add_email_to_users.rb
+++ b/db/migrate/012_add_email_to_users.rb
@@ -1,4 +1,4 @@
-class AddEmailToUsers < ActiveRecord::Migration
+class AddEmailToUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_column :users, :email, :string
   end
diff --git a/db/migrate/013_add_url_to_problem.rb b/db/migrate/013_add_url_to_problem.rb
--- a/db/migrate/013_add_url_to_problem.rb
+++ b/db/migrate/013_add_url_to_problem.rb
@@ -1,4 +1,4 @@
-class AddUrlToProblem < ActiveRecord::Migration
+class AddUrlToProblem < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :url, :string
   end
diff --git a/db/migrate/014_create_grader_processes.rb b/db/migrate/014_create_grader_processes.rb
--- a/db/migrate/014_create_grader_processes.rb
+++ b/db/migrate/014_create_grader_processes.rb
@@ -1,6 +1,6 @@
-class CreateGraderProcesses < ActiveRecord::Migration
+class CreateGraderProcesses < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :grader_processes do |t|
+    create_table :grader_processes, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :ip, :string, :limit => 20
       t.column :pid, :integer
       t.column :mode, :string
diff --git a/db/migrate/015_add_status_to_tasks.rb b/db/migrate/015_add_status_to_tasks.rb
--- a/db/migrate/015_add_status_to_tasks.rb
+++ b/db/migrate/015_add_status_to_tasks.rb
@@ -1,4 +1,4 @@
-class AddStatusToTasks < ActiveRecord::Migration
+class AddStatusToTasks < ActiveRecord::Migration[4.2]
   def self.up
     add_column :tasks, :status, :integer
     add_column :tasks, :updated_at, :datetime
diff --git a/db/migrate/016_add_task_to_grader_process.rb b/db/migrate/016_add_task_to_grader_process.rb
--- a/db/migrate/016_add_task_to_grader_process.rb
+++ b/db/migrate/016_add_task_to_grader_process.rb
@@ -1,4 +1,4 @@
-class AddTaskToGraderProcess < ActiveRecord::Migration
+class AddTaskToGraderProcess < ActiveRecord::Migration[4.2]
   def self.up
     add_column :grader_processes, :task_id, :integer
   end
diff --git a/db/migrate/017_rename_grader_process_column_ip_to_host.rb b/db/migrate/017_rename_grader_process_column_ip_to_host.rb
--- a/db/migrate/017_rename_grader_process_column_ip_to_host.rb
+++ b/db/migrate/017_rename_grader_process_column_ip_to_host.rb
@@ -1,4 +1,4 @@
-class RenameGraderProcessColumnIpToHost < ActiveRecord::Migration
+class RenameGraderProcessColumnIpToHost < ActiveRecord::Migration[4.2]
   def self.up
     rename_column :grader_processes, :ip, :host
   end
diff --git a/db/migrate/018_add_number_to_submissions.rb b/db/migrate/018_add_number_to_submissions.rb
--- a/db/migrate/018_add_number_to_submissions.rb
+++ b/db/migrate/018_add_number_to_submissions.rb
@@ -1,4 +1,4 @@
-class AddNumberToSubmissions < ActiveRecord::Migration
+class AddNumberToSubmissions < ActiveRecord::Migration[4.2]
   def self.up
     add_column :submissions, :number, :integer
 
diff --git a/db/migrate/019_create_test_requests.rb b/db/migrate/019_create_test_requests.rb
--- a/db/migrate/019_create_test_requests.rb
+++ b/db/migrate/019_create_test_requests.rb
@@ -1,6 +1,6 @@
-class CreateTestRequests < ActiveRecord::Migration
+class CreateTestRequests < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :test_requests do |t|
+    create_table :test_requests, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :user_id, :integer
       t.column :problem_id, :integer
       t.column :submission_id, :integer
@@ -10,7 +10,6 @@
 
       # these are similar to tasks
       t.column :status, :integer
-      t.column :updated_at, :datetime
 
       # these are intentionally similar to submissions
       t.column :submitted_at, :datetime
diff --git a/db/migrate/021_change_compiler_message_type_test_request.rb b/db/migrate/021_change_compiler_message_type_test_request.rb
--- a/db/migrate/021_change_compiler_message_type_test_request.rb
+++ b/db/migrate/021_change_compiler_message_type_test_request.rb
@@ -1,4 +1,4 @@
-class ChangeCompilerMessageTypeTestRequest < ActiveRecord::Migration
+class ChangeCompilerMessageTypeTestRequest < ActiveRecord::Migration[4.2]
   def self.up
     change_column :test_requests, :compiler_message, :text
   end
diff --git a/db/migrate/022_create_configurations.rb b/db/migrate/022_create_configurations.rb
--- a/db/migrate/022_create_configurations.rb
+++ b/db/migrate/022_create_configurations.rb
@@ -1,6 +1,6 @@
-class CreateConfigurations < ActiveRecord::Migration
+class CreateConfigurations < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :configurations do |t|
+    create_table :configurations, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :key, :string
       t.column :value_type, :string
       t.column :value, :string
diff --git a/db/migrate/023_add_runstat_columns_to_test_request.rb b/db/migrate/023_add_runstat_columns_to_test_request.rb
--- a/db/migrate/023_add_runstat_columns_to_test_request.rb
+++ b/db/migrate/023_add_runstat_columns_to_test_request.rb
@@ -1,4 +1,4 @@
-class AddRunstatColumnsToTestRequest < ActiveRecord::Migration
+class AddRunstatColumnsToTestRequest < ActiveRecord::Migration[4.2]
   def self.up
     add_column :test_requests, :running_time, :float
     add_column :test_requests, :exit_status, :string
diff --git a/db/migrate/024_create_sites.rb b/db/migrate/024_create_sites.rb
--- a/db/migrate/024_create_sites.rb
+++ b/db/migrate/024_create_sites.rb
@@ -1,6 +1,6 @@
-class CreateSites < ActiveRecord::Migration
+class CreateSites < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :sites do |t|
+    create_table :sites, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :name
       t.boolean :started
       t.datetime :start_time
diff --git a/db/migrate/025_add_site_to_user_and_add_default_site.rb b/db/migrate/025_add_site_to_user_and_add_default_site.rb
--- a/db/migrate/025_add_site_to_user_and_add_default_site.rb
+++ b/db/migrate/025_add_site_to_user_and_add_default_site.rb
@@ -1,4 +1,4 @@
-class AddSiteToUserAndAddDefaultSite < ActiveRecord::Migration
+class AddSiteToUserAndAddDefaultSite < ActiveRecord::Migration[4.2]
   def self.up
     default_site = Site.new({:name => 'default',
                               :started => false})
diff --git a/db/migrate/026_add_body_to_problems.rb b/db/migrate/026_add_body_to_problems.rb
--- a/db/migrate/026_add_body_to_problems.rb
+++ b/db/migrate/026_add_body_to_problems.rb
@@ -1,4 +1,4 @@
-class AddBodyToProblems < ActiveRecord::Migration
+class AddBodyToProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :body, :text
   end
diff --git a/db/migrate/027_create_descriptions.rb b/db/migrate/027_create_descriptions.rb
--- a/db/migrate/027_create_descriptions.rb
+++ b/db/migrate/027_create_descriptions.rb
@@ -1,6 +1,6 @@
-class CreateDescriptions < ActiveRecord::Migration
+class CreateDescriptions < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :descriptions do |t|
+    create_table :descriptions, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :body, :text
       t.column :markdowned, :boolean
       t.timestamps
diff --git a/db/migrate/028_refactor_problem_body_to_description.rb b/db/migrate/028_refactor_problem_body_to_description.rb
--- a/db/migrate/028_refactor_problem_body_to_description.rb
+++ b/db/migrate/028_refactor_problem_body_to_description.rb
@@ -1,4 +1,4 @@
-class RefactorProblemBodyToDescription < ActiveRecord::Migration
+class RefactorProblemBodyToDescription < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :description_id, :integer
     Problem.reset_column_information
diff --git a/db/migrate/029_add_test_allowed_to_problems.rb b/db/migrate/029_add_test_allowed_to_problems.rb
--- a/db/migrate/029_add_test_allowed_to_problems.rb
+++ b/db/migrate/029_add_test_allowed_to_problems.rb
@@ -1,4 +1,4 @@
-class AddTestAllowedToProblems < ActiveRecord::Migration
+class AddTestAllowedToProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :test_allowed, :boolean
     Problem.reset_column_information
diff --git a/db/migrate/030_create_announcements.rb b/db/migrate/030_create_announcements.rb
--- a/db/migrate/030_create_announcements.rb
+++ b/db/migrate/030_create_announcements.rb
@@ -1,6 +1,6 @@
-class CreateAnnouncements < ActiveRecord::Migration
+class CreateAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :announcements do |t|
+    create_table :announcements, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :author
       t.text :body
       t.boolean :published
diff --git a/db/migrate/031_add_supports_for_output_only_problems.rb b/db/migrate/031_add_supports_for_output_only_problems.rb
--- a/db/migrate/031_add_supports_for_output_only_problems.rb
+++ b/db/migrate/031_add_supports_for_output_only_problems.rb
@@ -1,4 +1,4 @@
-class AddSupportsForOutputOnlyProblems < ActiveRecord::Migration
+class AddSupportsForOutputOnlyProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :submissions, :source_filename, :string
     add_column :problems, :output_only, :boolean
diff --git a/db/migrate/032_create_messages.rb b/db/migrate/032_create_messages.rb
--- a/db/migrate/032_create_messages.rb
+++ b/db/migrate/032_create_messages.rb
@@ -1,6 +1,6 @@
-class CreateMessages < ActiveRecord::Migration
+class CreateMessages < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :messages do |t|
+    create_table :messages, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column "sender_id", :integer
       t.column "receiver_id", :integer
       t.column "replying_message_id", :integer
diff --git a/db/migrate/033_add_task_type_to_grader_processes.rb b/db/migrate/033_add_task_type_to_grader_processes.rb
--- a/db/migrate/033_add_task_type_to_grader_processes.rb
+++ b/db/migrate/033_add_task_type_to_grader_processes.rb
@@ -1,4 +1,4 @@
-class AddTaskTypeToGraderProcesses < ActiveRecord::Migration
+class AddTaskTypeToGraderProcesses < ActiveRecord::Migration[4.2]
   def self.up
     add_column 'grader_processes', 'task_type', :string
   end
diff --git a/db/migrate/034_create_countries.rb b/db/migrate/034_create_countries.rb
--- a/db/migrate/034_create_countries.rb
+++ b/db/migrate/034_create_countries.rb
@@ -1,6 +1,6 @@
-class CreateCountries < ActiveRecord::Migration
+class CreateCountries < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :countries do |t|
+    create_table :countries, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :name, :string
       t.timestamps
     end
diff --git a/db/migrate/035_add_country_to_sites_and_users.rb b/db/migrate/035_add_country_to_sites_and_users.rb
--- a/db/migrate/035_add_country_to_sites_and_users.rb
+++ b/db/migrate/035_add_country_to_sites_and_users.rb
@@ -1,4 +1,4 @@
-class AddCountryToSitesAndUsers < ActiveRecord::Migration
+class AddCountryToSitesAndUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_column 'sites', 'country_id', :integer
     add_column 'sites', 'password', :string
diff --git a/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb b/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb
--- a/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb
+++ b/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb
@@ -1,4 +1,4 @@
-class AddFrontpageFlagToAnnouncement < ActiveRecord::Migration
+class AddFrontpageFlagToAnnouncement < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, "frontpage", :boolean, :default => 0
   end
diff --git a/db/migrate/20081204122651_add_activated_to_users.rb b/db/migrate/20081204122651_add_activated_to_users.rb
--- a/db/migrate/20081204122651_add_activated_to_users.rb
+++ b/db/migrate/20081204122651_add_activated_to_users.rb
@@ -1,4 +1,4 @@
-class AddActivatedToUsers < ActiveRecord::Migration
+class AddActivatedToUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_column :users, :activated, :boolean, :default => 0
 
diff --git a/db/migrate/20081210021333_add_timestamps_to_users.rb b/db/migrate/20081210021333_add_timestamps_to_users.rb
--- a/db/migrate/20081210021333_add_timestamps_to_users.rb
+++ b/db/migrate/20081210021333_add_timestamps_to_users.rb
@@ -1,4 +1,4 @@
-class AddTimestampsToUsers < ActiveRecord::Migration
+class AddTimestampsToUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_timestamps :users
   end
diff --git a/db/migrate/20081215012843_change_user_login_string_limit.rb b/db/migrate/20081215012843_change_user_login_string_limit.rb
--- a/db/migrate/20081215012843_change_user_login_string_limit.rb
+++ b/db/migrate/20081215012843_change_user_login_string_limit.rb
@@ -1,4 +1,4 @@
-class ChangeUserLoginStringLimit < ActiveRecord::Migration
+class ChangeUserLoginStringLimit < ActiveRecord::Migration[4.2]
   def self.up
     execute "ALTER TABLE `users` CHANGE `login` `login` VARCHAR( 50 )"
   end
diff --git a/db/migrate/20090206145016_add_contest_flag_to_announcements.rb b/db/migrate/20090206145016_add_contest_flag_to_announcements.rb
--- a/db/migrate/20090206145016_add_contest_flag_to_announcements.rb
+++ b/db/migrate/20090206145016_add_contest_flag_to_announcements.rb
@@ -1,4 +1,4 @@
-class AddContestFlagToAnnouncements < ActiveRecord::Migration
+class AddContestFlagToAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, :contest_only, :boolean, :default => false
   end
diff --git a/db/migrate/20090416235658_add_common_ext_to_languages.rb b/db/migrate/20090416235658_add_common_ext_to_languages.rb
--- a/db/migrate/20090416235658_add_common_ext_to_languages.rb
+++ b/db/migrate/20090416235658_add_common_ext_to_languages.rb
@@ -1,4 +1,4 @@
-class AddCommonExtToLanguages < ActiveRecord::Migration
+class AddCommonExtToLanguages < ActiveRecord::Migration[4.2]
   def self.up
     # language.common_ext is a comma-separated list of common file
     # extensions.
diff --git a/db/migrate/20090426131044_add_terminated_to_grader_processes.rb b/db/migrate/20090426131044_add_terminated_to_grader_processes.rb
--- a/db/migrate/20090426131044_add_terminated_to_grader_processes.rb
+++ b/db/migrate/20090426131044_add_terminated_to_grader_processes.rb
@@ -1,4 +1,4 @@
-class AddTerminatedToGraderProcesses < ActiveRecord::Migration
+class AddTerminatedToGraderProcesses < ActiveRecord::Migration[4.2]
   def self.up
     add_column :grader_processes, :terminated, :boolean
   end
diff --git a/db/migrate/20090815171610_add_title_to_announcements.rb b/db/migrate/20090815171610_add_title_to_announcements.rb
--- a/db/migrate/20090815171610_add_title_to_announcements.rb
+++ b/db/migrate/20090815171610_add_title_to_announcements.rb
@@ -1,4 +1,4 @@
-class AddTitleToAnnouncements < ActiveRecord::Migration
+class AddTitleToAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, :title, :string
   end
diff --git a/db/migrate/20100113094740_create_test_pairs.rb b/db/migrate/20100113094740_create_test_pairs.rb
--- a/db/migrate/20100113094740_create_test_pairs.rb
+++ b/db/migrate/20100113094740_create_test_pairs.rb
@@ -1,6 +1,6 @@
-class CreateTestPairs < ActiveRecord::Migration
+class CreateTestPairs < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :test_pairs do |t|
+    create_table :test_pairs, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :problem_id
       t.text :input
       t.text :solution
diff --git a/db/migrate/20100124040107_add_description_to_config.rb b/db/migrate/20100124040107_add_description_to_config.rb
--- a/db/migrate/20100124040107_add_description_to_config.rb
+++ b/db/migrate/20100124040107_add_description_to_config.rb
@@ -1,4 +1,4 @@
-class AddDescriptionToConfig < ActiveRecord::Migration
+class AddDescriptionToConfig < ActiveRecord::Migration[4.2]
   def self.up
     add_column :configurations, :description, :text
   end
diff --git a/db/migrate/20100124054458_create_user_contest_stats.rb b/db/migrate/20100124054458_create_user_contest_stats.rb
--- a/db/migrate/20100124054458_create_user_contest_stats.rb
+++ b/db/migrate/20100124054458_create_user_contest_stats.rb
@@ -1,6 +1,6 @@
-class CreateUserContestStats < ActiveRecord::Migration
+class CreateUserContestStats < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :user_contest_stats do |t|
+    create_table :user_contest_stats, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :user_id
       t.timestamp :started_at
 
diff --git a/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb b/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb
--- a/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb
+++ b/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb
@@ -1,4 +1,4 @@
-class ChangeInputSolutionFieldLimitInTestPair < ActiveRecord::Migration
+class ChangeInputSolutionFieldLimitInTestPair < ActiveRecord::Migration[4.2]
   def self.up
     change_column :test_pairs, :input, :text, :limit => 1.megabytes
     change_column :test_pairs, :solution, :text, :limit => 1.megabytes
diff --git a/db/migrate/20100216105730_create_contests.rb b/db/migrate/20100216105730_create_contests.rb
--- a/db/migrate/20100216105730_create_contests.rb
+++ b/db/migrate/20100216105730_create_contests.rb
@@ -1,6 +1,6 @@
-class CreateContests < ActiveRecord::Migration
+class CreateContests < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :contests do |t|
+    create_table :contests, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :title
       t.boolean :enabled
 
diff --git a/db/migrate/20100216162324_create_contests_users_join_table.rb b/db/migrate/20100216162324_create_contests_users_join_table.rb
--- a/db/migrate/20100216162324_create_contests_users_join_table.rb
+++ b/db/migrate/20100216162324_create_contests_users_join_table.rb
@@ -1,6 +1,6 @@
-class CreateContestsUsersJoinTable < ActiveRecord::Migration
+class CreateContestsUsersJoinTable < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :contests_users, :id => false do |t|
+    create_table :contests_users, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :contest_id
       t.integer :user_id
     end
diff --git a/db/migrate/20100216162940_create_contests_problems_join_table.rb b/db/migrate/20100216162940_create_contests_problems_join_table.rb
--- a/db/migrate/20100216162940_create_contests_problems_join_table.rb
+++ b/db/migrate/20100216162940_create_contests_problems_join_table.rb
@@ -1,6 +1,6 @@
-class CreateContestsProblemsJoinTable < ActiveRecord::Migration
+class CreateContestsProblemsJoinTable < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :contests_problems, :id => false do |t|
+    create_table :contests_problems, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :contest_id
       t.integer :problem_id
     end
diff --git a/db/migrate/20100219014840_add_description_filename_to_problems.rb b/db/migrate/20100219014840_add_description_filename_to_problems.rb
--- a/db/migrate/20100219014840_add_description_filename_to_problems.rb
+++ b/db/migrate/20100219014840_add_description_filename_to_problems.rb
@@ -1,4 +1,4 @@
-class AddDescriptionFilenameToProblems < ActiveRecord::Migration
+class AddDescriptionFilenameToProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :description_filename, :string
   end
diff --git a/db/migrate/20100303095700_add_name_to_contests.rb b/db/migrate/20100303095700_add_name_to_contests.rb
--- a/db/migrate/20100303095700_add_name_to_contests.rb
+++ b/db/migrate/20100303095700_add_name_to_contests.rb
@@ -1,4 +1,4 @@
-class AddNameToContests < ActiveRecord::Migration
+class AddNameToContests < ActiveRecord::Migration[4.2]
   def self.up
     add_column :contests, :name, :string
   end    
diff --git a/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb b/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb
--- a/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb
+++ b/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb
@@ -1,4 +1,4 @@
-class AddForcedLogoutToUserContestStat < ActiveRecord::Migration
+class AddForcedLogoutToUserContestStat < ActiveRecord::Migration[4.2]
   def self.up
     add_column :user_contest_stats, :forced_logout, :boolean
   end
diff --git a/db/migrate/20100506163112_add_notes_to_announcements.rb b/db/migrate/20100506163112_add_notes_to_announcements.rb
--- a/db/migrate/20100506163112_add_notes_to_announcements.rb
+++ b/db/migrate/20100506163112_add_notes_to_announcements.rb
@@ -1,4 +1,4 @@
-class AddNotesToAnnouncements < ActiveRecord::Migration
+class AddNotesToAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, :notes, :string
   end
diff --git a/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb b/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb
--- a/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb
+++ b/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb
@@ -1,4 +1,4 @@
-class RenameConfigurationsToGraderConfigurations < ActiveRecord::Migration
+class RenameConfigurationsToGraderConfigurations < ActiveRecord::Migration[4.2]
   def change
     rename_table 'configurations', 'grader_configurations'
   end
diff --git a/db/migrate/20140823031747_add_more_detail_to_submission.rb b/db/migrate/20140823031747_add_more_detail_to_submission.rb
--- a/db/migrate/20140823031747_add_more_detail_to_submission.rb
+++ b/db/migrate/20140823031747_add_more_detail_to_submission.rb
@@ -1,4 +1,4 @@
-class AddMoreDetailToSubmission < ActiveRecord::Migration
+class AddMoreDetailToSubmission < ActiveRecord::Migration[4.2]
   def change
     add_column :submissions, :max_runtime, :float
     add_column :submissions, :peak_memory, :integer
diff --git a/db/migrate/20140826095949_create_logins.rb b/db/migrate/20140826095949_create_logins.rb
--- a/db/migrate/20140826095949_create_logins.rb
+++ b/db/migrate/20140826095949_create_logins.rb
@@ -1,6 +1,6 @@
-class CreateLogins < ActiveRecord::Migration
+class CreateLogins < ActiveRecord::Migration[4.2]
   def change
-    create_table :logins do |t|
+    create_table :logins, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :user_id
       t.string :ip_address
 
diff --git a/db/migrate/20140913060729_add_section_to_users.rb b/db/migrate/20140913060729_add_section_to_users.rb
--- a/db/migrate/20140913060729_add_section_to_users.rb
+++ b/db/migrate/20140913060729_add_section_to_users.rb
@@ -1,4 +1,4 @@
-class AddSectionToUsers < ActiveRecord::Migration
+class AddSectionToUsers < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :section, :string
   end
diff --git a/db/migrate/20140917150629_add_ip_to_submissions.rb b/db/migrate/20140917150629_add_ip_to_submissions.rb
--- a/db/migrate/20140917150629_add_ip_to_submissions.rb
+++ b/db/migrate/20140917150629_add_ip_to_submissions.rb
@@ -1,4 +1,4 @@
-class AddIpToSubmissions < ActiveRecord::Migration
+class AddIpToSubmissions < ActiveRecord::Migration[4.2]
   def change
     add_column :submissions, :ip_address, :string
   end
diff --git a/db/migrate/20150203153534_add_more_to_users.rb b/db/migrate/20150203153534_add_more_to_users.rb
--- a/db/migrate/20150203153534_add_more_to_users.rb
+++ b/db/migrate/20150203153534_add_more_to_users.rb
@@ -1,4 +1,4 @@
-class AddMoreToUsers < ActiveRecord::Migration
+class AddMoreToUsers < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :enabled, :boolean, default: 1
     add_column :users, :remark, :string
diff --git a/db/migrate/20150503164846_change_userid_on_login.rb b/db/migrate/20150503164846_change_userid_on_login.rb
--- a/db/migrate/20150503164846_change_userid_on_login.rb
+++ b/db/migrate/20150503164846_change_userid_on_login.rb
@@ -1,4 +1,4 @@
-class ChangeUseridOnLogin < ActiveRecord::Migration
+class ChangeUseridOnLogin < ActiveRecord::Migration[4.2]
   def up
     change_column :logins, :user_id, :integer
   end
diff --git a/db/migrate/20150827131927_create_submission_view_logs.rb b/db/migrate/20150827131927_create_submission_view_logs.rb
--- a/db/migrate/20150827131927_create_submission_view_logs.rb
+++ b/db/migrate/20150827131927_create_submission_view_logs.rb
@@ -1,6 +1,6 @@
-class CreateSubmissionViewLogs < ActiveRecord::Migration
+class CreateSubmissionViewLogs < ActiveRecord::Migration[4.2]
   def change
-    create_table :submission_view_logs do |t|
+    create_table :submission_view_logs, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :user_id
       t.integer :submission_id
 
diff --git a/db/migrate/20150827133841_add_last_ip_to_user.rb b/db/migrate/20150827133841_add_last_ip_to_user.rb
--- a/db/migrate/20150827133841_add_last_ip_to_user.rb
+++ b/db/migrate/20150827133841_add_last_ip_to_user.rb
@@ -1,4 +1,4 @@
-class AddLastIpToUser < ActiveRecord::Migration
+class AddLastIpToUser < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :last_ip, :string
   end
diff --git a/db/migrate/20150914090545_create_heart_beats.rb b/db/migrate/20150914090545_create_heart_beats.rb
--- a/db/migrate/20150914090545_create_heart_beats.rb
+++ b/db/migrate/20150914090545_create_heart_beats.rb
@@ -1,6 +1,6 @@
-class CreateHeartBeats < ActiveRecord::Migration
+class CreateHeartBeats < ActiveRecord::Migration[4.2]
   def change
-    create_table :heart_beats do |t|
+    create_table :heart_beats, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'user_id',:integer
       t.column 'ip_address',:string
 
diff --git a/db/migrate/20150914155101_add_status_to_heart_beat.rb b/db/migrate/20150914155101_add_status_to_heart_beat.rb
--- a/db/migrate/20150914155101_add_status_to_heart_beat.rb
+++ b/db/migrate/20150914155101_add_status_to_heart_beat.rb
@@ -1,4 +1,4 @@
-class AddStatusToHeartBeat < ActiveRecord::Migration
+class AddStatusToHeartBeat < ActiveRecord::Migration[4.2]
   def change
     add_column :heart_beats, :status, :string
   end
diff --git a/db/migrate/20150914223258_add_more_config.rb b/db/migrate/20150914223258_add_more_config.rb
--- a/db/migrate/20150914223258_add_more_config.rb
+++ b/db/migrate/20150914223258_add_more_config.rb
@@ -1,4 +1,4 @@
-class AddMoreConfig < ActiveRecord::Migration
+class AddMoreConfig < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.bypass_agreement', value_type: 'boolean', value:'true', description:'When false, a check box to accept license agreement appear at login and the user must click accept'
   end
diff --git a/db/migrate/20150916054105_update_heart_beat.rb b/db/migrate/20150916054105_update_heart_beat.rb
--- a/db/migrate/20150916054105_update_heart_beat.rb
+++ b/db/migrate/20150916054105_update_heart_beat.rb
@@ -1,4 +1,4 @@
-class UpdateHeartBeat < ActiveRecord::Migration
+class UpdateHeartBeat < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.heartbeat_response', value_type: 'string', value:'OK', description:'Heart beat response text'
     add_index :heart_beats, :updated_at
diff --git a/db/migrate/20161008050135_modify_grader_process.rb b/db/migrate/20161008050135_modify_grader_process.rb
--- a/db/migrate/20161008050135_modify_grader_process.rb
+++ b/db/migrate/20161008050135_modify_grader_process.rb
@@ -1,4 +1,4 @@
-class ModifyGraderProcess < ActiveRecord::Migration
+class ModifyGraderProcess < ActiveRecord::Migration[4.2]
   def up
     change_column :grader_processes, :host, :string
   end
diff --git a/db/migrate/20161014091417_create_testcases.rb b/db/migrate/20161014091417_create_testcases.rb
--- a/db/migrate/20161014091417_create_testcases.rb
+++ b/db/migrate/20161014091417_create_testcases.rb
@@ -1,6 +1,6 @@
-class CreateTestcases < ActiveRecord::Migration
+class CreateTestcases < ActiveRecord::Migration[4.2]
   def change
-    create_table :testcases do |t|
+    create_table :testcases, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.references :problem
       t.integer :num
       t.integer :group
diff --git a/db/migrate/20161031063337_add_config_view_test.rb b/db/migrate/20161031063337_add_config_view_test.rb
--- a/db/migrate/20161031063337_add_config_view_test.rb
+++ b/db/migrate/20161031063337_add_config_view_test.rb
@@ -1,4 +1,4 @@
-class AddConfigViewTest < ActiveRecord::Migration
+class AddConfigViewTest < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.view_testcase', value_type: 'boolean', value:'true', description:'When true, any user can view/download test data'
     #uglily and dirtily and shamelessly check other config and inifialize
diff --git a/db/migrate/20170123162543_change_testcase_size.rb b/db/migrate/20170123162543_change_testcase_size.rb
--- a/db/migrate/20170123162543_change_testcase_size.rb
+++ b/db/migrate/20170123162543_change_testcase_size.rb
@@ -1,4 +1,4 @@
-class ChangeTestcaseSize < ActiveRecord::Migration
+class ChangeTestcaseSize < ActiveRecord::Migration[4.2]
   def change
     change_column :testcases, :input, :text, :limit => 4294967295
     change_column :testcases, :sol, :text, :limit => 4294967295
diff --git a/db/migrate/20170124024527_add_view_testcase_to_problem.rb b/db/migrate/20170124024527_add_view_testcase_to_problem.rb
--- a/db/migrate/20170124024527_add_view_testcase_to_problem.rb
+++ b/db/migrate/20170124024527_add_view_testcase_to_problem.rb
@@ -1,4 +1,4 @@
-class AddViewTestcaseToProblem < ActiveRecord::Migration
+class AddViewTestcaseToProblem < ActiveRecord::Migration[4.2]
   def change
     add_column :problems, :view_testcase, :bool
   end
diff --git a/db/migrate/20170310110146_add_index_to_task.rb b/db/migrate/20170310110146_add_index_to_task.rb
--- a/db/migrate/20170310110146_add_index_to_task.rb
+++ b/db/migrate/20170310110146_add_index_to_task.rb
@@ -1,4 +1,4 @@
-class AddIndexToTask < ActiveRecord::Migration
+class AddIndexToTask < ActiveRecord::Migration[4.2]
   def change
     add_index :tasks, :submission_id
   end
diff --git a/db/migrate/20170427070345_add_heart_beat_full.rb b/db/migrate/20170427070345_add_heart_beat_full.rb
--- a/db/migrate/20170427070345_add_heart_beat_full.rb
+++ b/db/migrate/20170427070345_add_heart_beat_full.rb
@@ -1,4 +1,4 @@
-class AddHeartBeatFull < ActiveRecord::Migration
+class AddHeartBeatFull < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.heartbeat_response_full', value_type: 'string', value:'RESTART', description:'Heart beat response text when user got full score (set this value to the empty string to disable this feature)'
   end
diff --git a/db/migrate/20170911091143_create_groups.rb b/db/migrate/20170911091143_create_groups.rb
--- a/db/migrate/20170911091143_create_groups.rb
+++ b/db/migrate/20170911091143_create_groups.rb
@@ -1,17 +1,17 @@
-class CreateGroups < ActiveRecord::Migration
+class CreateGroups < ActiveRecord::Migration[4.2]
 
   def change
-    create_table :groups do |t|
+    create_table :groups, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :name
       t.string :description
     end
 
-    create_join_table :groups, :users do |t|
+    create_join_table :groups, :users, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       # t.index [:group_id, :user_id]
       t.index [:user_id, :group_id]
     end
 
-    create_join_table :problems, :groups do |t|
+    create_join_table :problems, :groups, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       # t.index [:problem_id, :group_id]
       t.index [:group_id, :problem_id]
     end
diff --git a/db/migrate/20170914150545_create_tags.rb b/db/migrate/20170914150545_create_tags.rb
--- a/db/migrate/20170914150545_create_tags.rb
+++ b/db/migrate/20170914150545_create_tags.rb
@@ -1,6 +1,6 @@
-class CreateTags < ActiveRecord::Migration
+class CreateTags < ActiveRecord::Migration[4.2]
   def change
-    create_table :tags do |t|
+    create_table :tags, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :name, null: false
       t.text :description
       t.boolean :public
diff --git a/db/migrate/20170914150742_create_problem_tags.rb b/db/migrate/20170914150742_create_problem_tags.rb
--- a/db/migrate/20170914150742_create_problem_tags.rb
+++ b/db/migrate/20170914150742_create_problem_tags.rb
@@ -1,6 +1,6 @@
-class CreateProblemTags < ActiveRecord::Migration
+class CreateProblemTags < ActiveRecord::Migration[4.2]
   def change
-    create_table :problems_tags do |t|
+    create_table :problems_tags, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.references :problem, index: true, foreign_key: true
       t.references :tag, index: true, foreign_key: true