Ansible creating a virtualenv

Question

How do you create a virtualenv for a specific python version using ansible. Is there a command in the ansible standard library?

I would like something like:

- virtualenv: dest=venv python_version:/usr/bin/python3

Answer 1

I have at times experienced some erratic behaviour with specifying virtualenv_command (e.g.: getting a python 2.7 executable in my virtualenv even though I specified to run the command with virtualenv-3.4.

If you experience that problem, you can create the virtualenv manually with the command module:

- name: Manually create the initial virtualenv
  command:
    cmd: virtualenv /user/home/venvs/myenv -p python3.4
    creates: "/user/home/venvs/myenv"

(note: by specifying creates this command will only run in the case that a virtualenv does not exist at /user/home/venvs/myenv).

Then you can install your requirements as normal with the pip command:

- name: Install requirements
  pip: 
    requirements=/my_app/requirements.txt 
    virtualenv=/user/home/venvs/myenv

Update

I've found that specifying the virtualenv_python (available in Ansible 2.0+) also seems to work in the case stated above. For example:

- name: Install requirements
  pip: 
    requirements: /my_app/requirements.txt
    virtualenv: /user/home/venvs/myenv
    virtualenv_python: python3.4

(with this you shouldn't need to manually create the virtualenv first)