oTree Ubuntu Server Setup

This is a step-by-step guide for setting up oTree on an Ubuntu server. This is, of course, not the only way to install oTree on a server and it involves several personal choices but I believe it might be helpful to some people.

Components

  • oTree running on Django

  • Nginx (Web server for reverse proxy)

  • Postgresql (Database)

  • Redis (Data cache)

  • Supervisor (Manages oTree)

Step 0 - Install necessary packages

These include

  • Python and related packages(python3.8-dev, python3-pip)

    • Database (Postgresql) and related packages (libpq-dev, postgresql-contrib, redis-server). We will install them with a single command below but before that a note about python version.

  • You should install a supported python version
    When I am writing this, oTree was supporting Python3.7 or 3.8. You should take a look at the “Installation” chapter. Note that I found the information only on the “MacOS” installation section. So you might want to dig a little bit to find the right version: https://otree.readthedocs.io/en/latest/install-macos.html#install-macos

  • Update the package list

sudo apt update
  • Install necessary packages:

sudo apt-get install python3.8 python3.8-dev python3.8-venv libpq-dev postgresql postgresql-contrib redis-server python3-pip build-essential libssl-dev libffi-dev 

Step 1 - Set up postgresql

  • Switch to the postgres user

sudo su - postgres

You will see that the left side of your commmand line will be changed to postgres@yourcomputername

  • Start the Postgres shell

psql
  • You will see that you are switched to Postgresql shell as on the left of the cursor you will see postgres=#

Create the database and set a password and quit Postgresql shell and switch back to your user. (Do not forget the semicolons(;) at the end of first two commands. They are sql commands and they require those semicolons to indicate that the command has finished) Replace the `dbpasswordhere’ string with a password you create, keeping the quotation marks enclosing the password.

CREATE DATABASE django_db;
alter user postgres password 'dbpasswordhere';
\q
exit
  • Add DATABASE_URL and REDIS_URL enviroment variables on your ~/.bashrc. You can use nano or your favourite text editor. To use nano write

nano ~/.bashrc

and add these lines to the file (replacing dbpasswordhere and adminpasshere. You can select your own admin password.

export DATABASE_URL=postgres://postgres:dbpasswordhere@localhost/django_db
export REDIS_URL=redis://localhost:6379
export OTREE_ADMIN_PASSWORD="adminpasswordhere"
export OTREE_PRODUCTION="1" # can set to 1                $
export OTREE_AUTH_LEVEL="STUDY" # can set to STUDY or DEMO$

If you are new to nano, you should at the end of your file and paste the lines above (with the password in the designated area). Press Ctrl+O to save the file and Ctrl + X to exit nano.

When you are done, source the code .bashrc file so the changes you made will be loaded.

source ~/.bashrc

Step 2 - oTree Installation

  • Create a virtual environment

python3.8 -m venv venvotree
  • Activate the virtual environment

source ~/venvotree/bin/activate

Add this line to the ~/.bashrc file as well so each time terminal runs, also the virtual enviroment runs. After that source ~/.bashrc file.

source ~/.bashrc

We will need to do that before trying otree because the enviromental variables we defined there earlier are necessary for oTree to run.

You should be seeing (venv) on the left side of the screen.

  • Install wheel pip install wheel

  • Install oTree python package

pip install -U otree
  • Create oTree project folder

otree startproject oTree
  • Go to the folder and install requirements

cd oTree
pip install -r requirements.txt 
  • You can run the server with otree prodserver 8000 command. That’s where the oTree will run. however before that, to test it over http, you can run it like this:

sudo -E env "PATH=$PATH" otree prodserver 80

Then you should be able to reach oTree from your browser

You might(actuall should) get a “database not ready error”. in this case try

otree resetdb

and then run the server again.

Step 3 - Install nginx

  • Install nginx

sudo apt install nginx
  • Check the status

systemctl status nginx
  • Allow firewall to Nginx

sudo ufw allow 'Nginx Full' 
sudo ufw allow ssh
sudo ufw allow 'OpenSSH'
sudo ufw enable
  • You might not run oTree server on the port 80 when you run it from the browser after you enable ufw. This is alright as nginx will be the reverse proxy for that. Nevertheless you can stop nginx by sudo service nginx stop

Test the nginx invitation by going to http://your-host-name. Sometimes oTree’s redirection to /demo/ page stay in the cache of the browser. So you might be redirected to your-host-name/demo/. If this happens you can delete the cache or basically open a private browser and try there.

  • Unlink the default website

sudo unlink /etc/nginx/sites-enabled/default

Create the reverse proxy file:

sudo nano /etc/nginx/sites-available/reverse-proxy.conf

with the contents (do not forget to replace the server_name YOURHOSTNAMESHOULDBEHERE):

map $http_upgrade $connection_upgrade {
    default upgrade;
        '' close;
	} 


server {
        access_log /var/log/nginx/reverse-access.log;
        error_log /var/log/nginx/reverse-error.log;

	server_name YOURHOSTNAMESHOULDBEHERE;

	location ^~/_static/{
	root /home/cloud/oTree/;
	include /etc/nginx/mime.types;
	}

	location / {
	   proxy_buffering off;
	   proxy_pass http://localhost:8000;
	   proxy_http_version 1.1;
	   proxy_set_header Upgrade $http_upgrade;
	   proxy_set_header Connection $connection_upgrade; 
	   proxy_set_header HOST $host;
	   proxy_set_header X-Real-Ip $remote_addr;
	   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	   proxy_set_header X-Forwarded-Host $server_name;
	   proxy_set_header X-Forwarded-Proto $scheme;
	   proxy_set_header X-Forwarded-Port $server_port;
	   }

}


  • Create link to the enabled site

sudo ln -s /etc/nginx/sites-available/reverse-proxy.conf /etc/nginx/sites-enabled/reverse-proxy.conf
  • Check config test nginx

sudo service nginx configtest
  • Restart nginx

sudo service nginx restart
  • Run oTree server

sudo -E env "PATH=$PATH" otree prodserver 8000

and check if it worked by going to your server’s url from your browser. You should be seeing oTree admin panel. If everything seems okay, stop the server and we will automatize the process using supervisor.

Step 4 - Set up Supervisor

  • Install supervisor

sudo apt install supervisor
  • Start supervisor

sudo service supervisor start
  • Create supervisor config for otree

sudo nano /etc/supervisor/conf.d/otree.conf
[program:otree]
command=/home/cloud/venvotree/bin/otree runprodserver 8000
directory=/home/cloud/oTree
stdout_logfile=/home/cloud/otree-supervisor.log
stderr_logfile=/home/cloud/otree-supervisor-errors.log
autostart=true
autorestart=true
environment=
  PATH="/home/cloud/venvotree/bin/:%(ENV_PATH)s",
  DATABASE_URL="postgres://postgres:dbsappwordhere@localhost/django_db",
  REDIS_URL="redis://localhost:6379",
  OTREE_ADMIN_PASSWORD="adminpasswordhere",
  OTREE_PRODUCTION="1", # can set to 1                                                           
  OTREE_AUTH_LEVEL="STUDY", # can set to STUDY or DEMO 
  • Reread supervisor

sudo supervisorctl reread
  • Note: If you see such an error on supervisor reread

No such file or directory: file: /usr/lib/python2.7/socket.py line: 228

it means that supervisor is not running. Try to figure our what’s wrong and run again.

  • Restart supervisor

sudo service supervisor restart

Step 5 - Using secure connection (https) by installing ssh (optional)

We will use self signed Let’s encrypt

  • Add repo

sudo add-apt-repository ppa:certbot/certbot
  • install certbot for nginx

sudo apt install python-certbot-nginx
  • Create the certificate

sudo certbot --nginx -d yourhostnamehere

When it asks

Please choose whether or not to redirect HTTP traffic to HTTPS, removing HTTP access.

1: No redirect - Make no further changes to the webserver configuration.
2: Redirect - Make all requests redirect to secure HTTPS access. Choose this for
new sites, or if you're confident your site works on HTTPS. You can undo this
change by editing your web server's configuration.
- - - - - - - - - - - - - - 

Choose 2

  • Restart nginx

sudo service nginx restart

Your server is ready!