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Welcome to the Autolab Docs

Autolab is a course management platform that enables instructors to offer autograded programming assignments to their students. The two key ideas in Autolab are autograding that is, programs evaluating other programs, and scoreboards that display the latest autograded scores for each student. Autolab also provides gradebooks, rosters, handins/handouts, lab writeups, code annotation, manual grading, late penalties, grace days, cheat checking, meetings, partners, and bulk emails.

You can install Autolab easily by using our recommended Docker Compose installation guide, or by following the steps from a manual install at Getting Started.

For information on how to use Autolab for your course see the Guide for Instructors. To learn how to write an autograded lab see the Guide for Lab Authors.

Demonstration Site

If you would like to check out Autolab prior to installation, go over to our Demo Site! Login through Developer Login with the email:

This is a demonstration website. It refreshes at 0,6,12,18 Hours (UTC) daily, and it is publicly accessible, so please only use it for your exploration. Do not use this site to store important information.

Try the following in order:

Create a new course

Click on Manage Autolab (top-right navigation bar) > Create New Course. Fill in the name and semester, and then create to see your course on the homepage.

(NOTE: the email doesn't need to be real here)

Create an Autograded Lab Assessment.

Go into the course you have just created, click on Install Assessment. You can install a simple autograded lab, called hello lab. Download hello.tar and install it using the Import from Tarball option.

In the hello lab, students are asked to write a file called hello.c. The autograder checks that the submitted hello.c program compiles and runs with an exit status of zero. If so, the submission gets 100 points. Otherwise it gets 0 points.

Try submitting to the autograded hello lab

  1. Create and submit a hello.c file.

    #include <stdio.h>
    int main()
            printf("Hello, World!");
            return 0;
  2. Refresh the submitted entries page to see the autograded score appear

  3. Click on a sub score, in this case the 100.0 under the Correctness heading, to see the output from the autograder.

For more information on hello lab, or how to create your own lab, go to Guide for Lab Authors!

Create a PDF homework assessment

Autolab can also handle pdf submissions as well!

Click on Install Assessment, then on Assessment Builder. Name your assessment, and give it a category and click Create Assessment!.

Because it defaults to accepting .c files, we would like to change it to *.pdf. Click on Edit Assessment > Handin and then change the Handin filename to handin.pdf instead of handin.c and save the changes

Try submitting to the pdf homework asssessment.

  1. Submit a .pdf file.
  2. Look at your submission using the magnifying glass icon

Grading submissions

Click on Grade Submissions, and then the arrow button to open up student submissions. For details on the relevant features for an Instructor, go to Guide for Instructor

Getting Started

Autolab consists of two services: (1) the Ruby on Rails frontend, and (2) Tango, the RESTful Python autograding server. Either service can run independently without the other. But in order to use all features of Autolab, we highly recommend installing both services.

Currently, we have support for installing Autolab on Ubuntu 18.04+, and Mac OSX.

The following instructions are for manual installation of Autolab. We strongly encourage you to try out the Docker Compose installation method which is much faster and easier. It is production ready and comes deployed with MySQL and TLS.

Mac OSX 10.11+

Follow the step-by-step instructions below:

  1. Install rbenv (use the Basic GitHub Checkout method)

  2. Install ruby-build as an rbenv plugin:

    git clone ~/.rbenv/plugins/ruby-build

    Restart your shell at this point in order to start using your newly installed rbenv

  3. Clone the Autolab repo into home directory and enter it:

    cd ~/
    git clone && cd Autolab
  4. Install the correct version of ruby:

    rbenv install $(cat .ruby-version)

    At this point, confirm that rbenv is working (you might need to restart your shell):

    $ which ruby
    $ which rake

    Note that Mac OSX comes with its own installation of ruby. You might need to switch your ruby from the system version to the rbenv installed version. One option is to add the following lines to ~/.bash_profile:

    export RBENV_ROOT=<rbenv folder path on your local machine>
    eval "$(rbenv init -)"
  5. Install bundler:

    gem install bundler
    rbenv rehash
  6. Install the required gems (run the following commands in the cloned Autolab repo):

    cd bin
    bundle install

    Refer to the FAQ for issues installing gems

  7. Install one of two database options

    • SQLite should only be used in development
    • MySQL can be used in development or production
  8. Configure your database:

    cp config/database.yml.template config/database.yml

    Edit database.yml with the correct credentials for your chosen database. Refer to the FAQ for any issues.

  9. Configure school/organization specific information (new feature):

    cp config/school.yml.template config/school.yml

    Edit school.yml with your school/organization specific names and emails

  10. Configure the Devise Auth System with a unique key (run these commands exactly - leave <YOUR-SECRET-KEY> as it is):

    cp config/initializers/devise.rb.template config/initializers/devise.rb
    sed -i "s/<YOUR-SECRET-KEY>/`bundle exec rails secret`/g" config/initializers/devise.rb

    Fill in <YOUR_WEBSITE> in the config/initializers/devise.rb file. To skip this step for now, fill with

  11. Create and initialize the database tables:

    bundle exec rails db:create
    bundle exec rails db:migrate

    Do not forget to use bundle exec in front of every rake/rails command.

  12. Populate dummy data (development only):

    bundle exec rails autolab:populate
  13. Start the rails server:

    bundle exec rails s -p 3000
  14. Go to localhost:3000 and login with Developer Login:

    Email: "".
  15. Install Tango, the backend autograding service.

  16. Now you are all set to start using Autolab! Visit the Guide for Instructors and Guide for Lab Authors pages for more info.

Ubuntu 18.04+

This set of instruction is meant to install of AutoLab v2.40 on Ubuntu 18.04 LTS.

  1. Upgrade system packages and installing prerequisites

    sudo apt-get update
    sudo apt-get upgrade
    sudo apt-get install build-essential git libffi-dev zlib1g-dev autoconf bison build-essential libssl-dev libyaml-dev libreadline6-dev libncurses5-dev libgdbm5 libgdbm-dev libmysqlclient-dev libjansson-dev ctags
  2. Cloning Autolab repo from Github to ~/Autolab

    cd ~/
    git clone
    cd Autolab
  3. Setting up rbenv and ruby-build plugin

    cd ~/
    git clone ~/.rbenv
    echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
    echo 'eval "$(rbenv init -)"' >> ~/.bashrc
    source ~/.bashrc
    ~/.rbenv/bin/rbenv init
    git clone ~/.rbenv/plugins/ruby-build
  4. Installing Ruby (Based on ruby version)

    cd Autolab
    rbenv install  `cat .ruby-version`
  5. Installing SQLite

    sudo apt-get install sqlite3 libsqlite3-dev
  6. Installing MySQL. (If you would just like to test Autolab, then you can skip this step by using SQLite) Following instructions from How to Install MySQL on Ubuntu.

    sudo apt install mysql-server
    sudo mysql_secure_installation
    > There will be a few questions asked during the MySQL setup.
    * Validate Password Plugin? N
    * Remove Annonymous Users? Y
    * Disallow Root Login Remotely? Y
    * Remove Test Database and Access to it? Y
    * Reload Privilege Tables Now? Y
  7. (If you are using MySQL) Create a new user with access to autolab_test and autolab_development databases. Because a password rather than auth_socket is needed, we need to ensure that user uses mysql_native_password

    sudo mysql
    mysql> CREATE USER 'user1'@'localhost' IDENTIFIED WITH mysql_native_password BY '<password>';
    mysql> exit;
  8. Installing Rails

    cd Autolab
    gem install bundler
    rbenv rehash
    bundle install
  9. Initializing Autolab Configs

    cd Autolab
    cp config/database.yml.template config/database.yml
    cp config/school.yml.template config/school.yml
    cp config/initializers/devise.rb.template config/initializers/devise.rb
    sed -i "s/<YOUR-SECRET-KEY>/`bundle exec rails secret`/g" config/initializers/devise.rb
    cp config/autogradeConfig.rb.template config/autogradeConfig.rb
  10. (Using MySQL) Editing Database YML. Change the and fields in config/database.yml to the username and password that has been set up for the mysql. For example if your username is user1, and your password is 123456, then your yml would be

        adapter: mysql2
        database: autolab_development
        pool: 5
        username: user1
        password: '123456'
        socket: /var/run/mysqld/mysqld.sock
        host: localhost
            sql_mode: NO_ENGINE_SUBSTITUTION
        adapter: mysql2
        database: autolab_test
        pool: 5
        username: user1
        password: '123456'
        socket: /var/run/mysqld/mysqld.sock
        host: localhost
            sql_mode: NO_ENGINE_SUBSTITUTION
  11. (Using SQLite) Editing Database YML. Comment out the configurations meant for MySQL in config/database.yml, and insert the following

        adapter: sqlite3
        database: db/autolab_development
        pool: 5
        timeout: 5000
        adapter: sqlite3
        database: db/autolab_test
        pool: 5
        timeout: 5000
  12. Granting permissions on the databases. Setting global sql mode is important to relax the rules of mysql when it comes to group by mode

    (access mysql using your root first to grant permissions)
    mysql> grant all privileges on autolab_development.* to '<username>'@localhost;
    mysql> grant all privileges on autolab_test.* to '<username>'@localhost;
    mysql> SET GLOBAL sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));
    mysql> exit
  13. Initializing Autolab Database

    cd Autolab
    bundle exec rails db:create
    bundle exec rails db:reset
    bundle exec rails db:migrate
  14. Populating sample course & students

    cd Autolab
    bundle exec rails autolab:populate
  15. Run Autolab!

    cd Autolab
    bundle exec rails s -p 3000 --binding=
  16. Visit localhost:3000 on your browser to view your local deployment of Autolab, and login with Developer Login

    Email: ""
  17. Install Tango, the backend autograding service.

  18. If you would like to deploy the server, you can try out Phusion Passenger

  19. Now you are all set to start using Autolab! Visit the Guide for Instructors and Guide for Lab Authors pages for more info.


This is a general list of questions that we get often. If you find a solution to an issue not mentioned here, please contact us at

Ubuntu Script Bugs

If you get the following error

Failed to fetch
Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)

then follow the solution in this post.

Where do I find the MySQL username and password?

If this is your first time logging into MySQL, your username is 'root'. You may also need to set the root password:

Start the server:

sudo /usr/local/mysql/support-files/mysql.server start

Set the password:

mysqladmin -u root password "[New_Password]"

If you lost your root password, refer to the MySQL wiki

Bundle Install Errors

This happens as gems get updated. These fixes are gem-specific, but two common ones are


bundle config build.eventmachine --with-cppflags=-I/usr/local/opt/openssl/include


bundle config build.libv8 --with-system-v8

Run bundle install again

If this does not work, another option would be

bundle update libv8

Because updating libv8 has dependency on other gems, it might fail due to a need to update other gems. Just do

bundle update <gem>

according to the error messages until all gems are up to date.

Run bundle install again

If neither of these works, try exploring this StackOverflow link

Can't connect to local MySQL server through socket

Make sure you've started the MySQL server and double-check the socket in config/database.yml

The default socket location is /tmp/mysql.sock.

I forgot my MySQL root password

You can reset it following the instructions on this Stack Overflow post

If mysql complains that the password is expired, follow the instructions on the second answer on this post

MySQL Syntax Error

If you get the following error

Mysql2::Error: You have an error in your SQL syntax

this may be an issue with using an incompatible version of MySQL. Try switching to MySQL 5.7 if you are currently using a different version.

Undefined method 'devise' for User

You most likely missed the step of copying 'config/initializers/devise.rb.template' to 'config/initializers/devise.rb' and setting your secret key in the setup instructions.