DevOps16 - Create Python Virtual Environment
- Home
- 1 - Ubuntu 16.04 user setup
- 2 - Install Nginx
- 3 - Install Phusion Passenger
- 4 - Install MongoDB
- 5 - Python venv
- 6 - Deploy via Git
- 7 - Migrate Mongodb
- Various commands
Ubuntu’s latest Long Term Support (LTS) operating system was released last month, in April 2016. The 16.04 update for Ubuntu is known as “Xenial Xerus” and it’s the first Ubuntu release to include Python 3 as the default Python installation. We can use this new Ubuntu release along with Python version 3.5 to start a new Flask web application project.
Install System Packages
We can see the python3 system version Ubuntu comes with and where its
executable is stored using these commands.
python3 --version
which python3
Install required system packages, using superuser login with sudo.
Enter y to let the system package installation process do its job.
sudo apt-get install virtualenv python-pip python3-dev
Create virtual environment
Where to store virtual environments?
Option 1: Place in APP’s root folder
If you want to create the Python virtual environment in the APP root directory, please follow the tutorial Deploy Flask App with Git to set up APP directory.
Create a new virtualenv. This example uses the apps root folder.
cd /var/www/APP_NAME
# specify the system python3 installation
virtualenv --python=/usr/bin/python3 venv
Activate the virtualenv.
source /var/www/APP_NAME/venv/bin/activate
Our prompt will change after we properly activate the virtualenv.
Our virtualenv is now activated with Python 3. We can install
dependencies. For example, from a requirements.txt file located in APP’s code file:
cd /var/www/APP_NAME/code
sudo pip install -r requirements.txt
Option 2: Place in common venvs folder
Create a common folder to store virtual environments.
For example, in user’s home directory.
cd ~
mkdir venvs
Create a new virtualenv, specifying version.
# specify the system python3 installation
virtualenv --python=/usr/bin/python3 venvs/APP_NAME
Activate the virtualenv.
source /venvs/APP_NAME/bin/activate
Our prompt will change after we properly activate the virtualenv.
Our virtualenv is now activated with Python 3. We can install
dependencies. For example, from a requirements.txt file located in APP’s code file:
cd /var/www/APP_NAME/code
sudo pip install -r requirements.txt
Point Phusion passenger to venv
Edit passenger config file to point to APP’s virtualenv.
Example from phusionpassenger.com
http {
passenger_root ...;
# Use Ruby 2.1 by default.
passenger_ruby /usr/bin/ruby2.1;
# Use Python 2.6 by default.
passenger_python /usr/bin/python2.6;
# Use /usr/bin/node by default.
passenger_nodejs /usr/bin/node;
server {
# This Rails web app will use Ruby 2.2.1, as installed by RVM
passenger_ruby /usr/local/rvm/wrappers/ruby-2.2.1/ruby;
listen 80;
server_name www.bar.com;
root /webapps/bar/public;
# If you have a web app deployed in a sub-URI, customize
# passenger_ruby/passenger_python inside a `location` block.
# The web app under www.bar.com/blog will use JRuby 1.7.1
location ~ ^/blog(/.*|$) {
alias /websites/blog/public$1;
passenger_base_uri /blog;
passenger_app_root /websites/blog;
passenger_document_root /websites/blog/public;
passenger_enabled on;
passenger_ruby /usr/local/rvm/wrappers/jruby-1.7.1/ruby;
}
}
server {
# This Flask web app will use Python 3.0
passenger_python /usr/bin/python3.0;
listen 80;
server_name www.baz.com;
root /webapps/baz/public;
}
}
