Ansible - Activating virtual env with become_user - ansible

Question

I want to do create a user for my CKAN installation and then activate a virtual environment as the user and install something.
- name: Add a CKAN user
user:
name: ckan
comment: "CKAN User"
shell: /sbin/nologin
create_home: yes
home: /usr/lib/ckan
state: present
- name: chmod 755 /usr/lib/ckan
file:
path: /usr/lib/ckan
mode: u=rwX,g=rX,o=rX
recurse: yes
- name: Create Python virtual env
command: virtualenv --no-site-packages default
become: yes
become_user: ckan
- name: Activate env
command: . default/bin/activate
- name: Activate env
command: pip install setuptools==36.1
I know it's generally not the most 'Ansible' implementation but I'm just trying to get something to work.
The error is in 'Create Python virtual env'. I am getting an error in that line for
In a command line I would just run:
su -s /bin/bash - ckan
But how do I achieve this here? I thought become_user would do it?

Answer 1

If you already have the path to the user's folder and have set the appropriate permissions, then you can directly use the Ansible pip module to create a virtual environment in that folder and install packages. So, IIUC you do not require the following tasks
Create Python virtual env
instead of this task, you can just add the parameter virtualenv_command to the pip module in order to create the virtual environment (if it does not already exist)
Activate env (x2)
if you want to install packages into the virtual environment using the Ansible pip module, then these 2 tasks are not required
Also, you can use the parameter virtualenv_site_packages in order to exclude the global packages in your virtual environment. You do not need to use the parameter extra_args to do this.
If you want to install a single package into a virtual environment, then you can replace your last 3 tasks with the following task
tasks:
- name: Create Python virtual env and install one package inside the virtual env
pip:
name: setuptools==36.1
virtualenv: /path/to/ckan/user/home/folder # <--- path to user's home folder*
virtualenv_command: virtualenv
virtualenv_site_packages: no # <---- added this parameter to exclude site packages
virtualenv_python: python3.7
If you want to install many packages from requirements-docs.txt, then you could use this approach
tasks:
- name: Create Python virtual env and install multiple packages inside the virtual env
pip:
requirements: /path/to/ckan/user/home/folder/requirements-docs.txt
virtualenv: /path/to/ckan/user/home/folder # <--- path to user's home folder*
virtualenv_command: virtualenv
virtualenv_site_packages: no # <---- added this parameter to exclude site packages
virtualenv_python: python3.7
* the user's home folder must exist before executing this task

Answer 2

The following worked:
- name: Install setuptools into venv
pip:
name: Setuptools==36.1
virtualenv: '{{ path_to_virtualenv }}'
Become user was not needed.
Another example:
- name: Install ckan python modules
pip: name="requirements-docs.txt" virtualenv={{ ckan_virtualenv }} state=present extra_args="--ignore-installed -r"