systemd-uwsgi-example

Example config files for running Flask application using uWSGI application server in emperor mode, with nginx as a frontend.

Installation:

Install apropriate packages:

• python
• python-pip
• python-virtualenv
• nginx
• gcc (for uwsgi compilation)

Copy nginx config Copy example_nginx.conf to /etc/nginx/conf.d

Copy systemd config Copy uwsgi-example to /usr/bin Copy uwsgi-example.service to /usr/lib/systemd/system

Create directories for application:

mkdir -p /opt/example/log
mkdir -p /opt/example/venv
mkdir -p /opt/example/run

Copy application files:

• app.py and requirements.txt to /opt/example
• example.ini to /opt/example/run

Install and configure application virtualenv:

virtualenv /opt/example/venv
/opt/example/venv/bin/pip install -r /opt/example/requirements.txt

Fix permissions:

chown -R nginx:nginx /opt/example

Enable service:

systemctl enable uwsgi-example.service

Run the service:

service uwsgi-example start

Navigate to http://127.0.0.1:8080

Horizontally scaling single application

If your application can be run simultaneously, by just invoking it multiple times from the same directory, you simply have to:

• add another copy of .ini file with different port
• add another entry in nginx upstream config with the new port number
• copy new .ini file to vassals dir (emperor will spawn new instance of your app.)
• reload nginx to pick-up new config