Unable to install more than one Airflow Extra Package

[AdriMarteau]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Checked that your issue isn't already filled: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aidealista
  • Checked that there is not already provided the described functionality

Description

When specifying more than 1 airflow extra package, the task Airflow | Installing Airflow Extra Packages fails with error:

(item=['apache-airflow[celery]', 'apache-airflow[postgres]']) => {"changed": false, "item": ["apache-airflow[celery]", "apache-airflow[postgres]"], "msg": "'version' argument is ambiguous when installing multiple package distributions. Please specify version restrictions next to each package in 'name' argument."}

Steps to Reproduce

1. Set in a vars file

airflow_version: 1.10.0
airflow_extra_packages: [celery,postgres]

2. Deploy Airflow using the role

Expected behavior: deployment to work

Actual behavior: deployment fails

Reproduces how often: Everytime

Versions

1.7.2

Additional Information

This also generate a warning:

[DEPRECATION WARNING]: Invoking "pip" only once while using a loop via squash_actions is deprecated. Instead of using a loop to supply multiple items and specifying `name: "apache-airflow[{{ item }}]"`, please use `name: '{{
airflow_extra_packages }}'` and remove the loop. This feature will be removed in version 2.11.

[AdriMarteau]

Not sure that it was intended but setting (without brackets): airflow_extra_packages: celery,postgres seems to work but the warning remains

[jnogol]

Hi @AdriMarteau

Which Ansible version are you using?

[AdriMarteau]

I am on ansible 2.7.6

[jnogol]

Thing is more delicate than I expected. Technically, all members of a list are lines beginning at the same indentation level starting with a "- " (a dash and a space): so we will specify the format in the defaults file and make a comma-separated list for Ansible versions greater than 2.7:

"apache-airflow[{{ airflow_extra_packages | join(', ') }}]"

This way, the role will have a backwards compatibility and will be able to use with Ansible 2.11