ansible-nginx-uwsgi-supervisor

An Ansible role to setup and manage a UWSGI app via supervisor, and served up on a NGINX web server. The goal of this role is to make deployment of WSGI app as a simple and sane as possible. Additionally the role provides sane defaults for logging and folder structure setup.

Requirements

• aptitude or python-apt (required by apt tasks)
• python > 2.5 (required by ini_file tasks)

This role is designed to work against a modern Ubuntu system. (Tested on Ubuntu 13.10 and 14.04) It should theoretically work on older versions of Ubuntu or Debian based systems.

Role Variables

There are a few crucial variables that you need to configure for your particular WSGI powered app. They are broken up into sections and described below:

App Settings

• app_name:
  • The name of WSGI app to manage via this role.
  • Used as a prefix through out the role.
• app_root_path:
  • The path to the root folder of the app.
  • Default: {{ web_root_path }}/{{ app_name }}_webapp"

NGINX

• app_nginx_hostname:
  • The DNS hostname that the application serves.
  • Default: localhost
• app_nginx_app_static:
  • The path to the static elements of the site (templates, CSS, images, etc.)
  • Default: app_root_path/app_name/static/

UWSGI

• app_uwsgi_port:
  • The port number that the WSGI runs on and accepts requests forwarded from NGINX.
  • Default: 8001
• app_uwsgi_executable:
  • The method executed by UWSGI to create a WSGI running app. Usually a WSGI factory method or module in the app.
  • Default: app:make_wsgi_app()

General Web:

These variables are not as crucial to configure. They do give good defaults for configuring the system in a consistent, POSIX/LSB-friendly and user-friendly manner. See the section on Default File Structure for more details.

• web_root_path:
  • The root of the entire web app structure include configuration and logging.
  • Default: /srv/www
• web_server_group:
  • The user group responsible for starting, stopping and managing the web and app servers on the target machine.
  • Default: www-data

Main (Internal) Variables

The following variables are part of the internals of the role. However if you really want to, you can tweak them to work with your setup:

• web_user:
  • The non-root user who is allowed to control web + app servers on the target machine.
  • Default: current user
• virtualenv_root_path:
  • The common root directory of Python virtual environments associated with running the UWSGI app + server.
  • Default: /srv/www/virtualenvs/
• uwsgi_venv:
  • The virtual environment where UWSGI is installed.
  • Default: virtualenv_root/uwsgi
• app_venv:
  • The virtual environment where the dependencies of the WSGI app is installed.
  • Default: virtualenv_root/app_name
• nginx_app_conf:
  • The filename of the NGINX configuration for the app.
  • Default: app_name_uwsgi_nginx.conf
• supervisor_app_config:
  • The filename of the supervisor configuration for the app.
  • Default: app_name_supervisor.conf
• uwsgi_config_path:
  • The path to the UWSGI configurations.
  • Default: /srv/www/config/uwsgi
• uwsgi_app_ini:
  • The filename of the UWSGI INI configuration for the app.
  • Default: app_name_uwsgi.ini
• uwsgi_service_name:
  • The name of the UWSGI setup for the app according to supervisor.
  • Default: app_name_uwsgi

Example Playbook

The simplest way to include the role in your playbook is to copy the below configuration. Remember to modify the app_name, nginx_hostname and uwsgi_app_executable parameters especially.

- hosts: servers
  sudo: yes

  roles:
      - { role: ansible-nginx-uwsgi-supervisor, 
          app_name: app, 
          app_nginx_hostname: app.domain.net,
          app_uwsgi_port: 8080, 
          app_uwsgi_executable: "app.build:make_wsgi_app()" }

A comprehensive example can be found in the [ansible-rookeries role] (https://bitbucket.org/dorianpula/ansible-rookeries) that uses this role as a base to deploy a Flask-based webapp.

Default File Structure

By default the role will organize files in the following directory structure:

/srv/www
├── config
│   ├── nginx -> /etc/nginx
│   ├── supervisor -> /etc/supervisor
│   └── uwsgi
├── logs
│   ├── nginx -> /var/log/nginx
│   ├── supervisor -> /var/log/supervisor
│   └── uwsgi
├── app_webapp
│   ├── requirements.txt
│   └── app
└── virtualenvs
    ├── app
    └── uwsgi

License

BSD

Author Information

Dorian Pula

• twitter: @dorianpula
• email: dorian.pula at amber-penguin.software.ca
• www: http://amber-penguin-software.ca

This role is a spin-off of the technology developed for the [Rookeries project] (http://rookeri.es/)