Dynamically load environment variables from config file in Ansible

I have the following (simplified) play:

- hosts: testing

  roles:
     - nginx
  vars_files:
     - config.yml
  environment:
    http_proxy: http://proxy.example.com:8080

Now, when I run my code, I can read process.env.http_proxy. I would however like to be able to set other environment variables dynamically under environment. For example, in my config.yml I have the following:

application_variables:
  - key: "NODE_ENV"
    value: "production"
  - key: "PORT"
    value: "3000"

How would I get the values from application_variables to be dynamically created under environment? I've tried a few different solutions I found out there to no avail.

Solution

You can feed the environment parameter from a templated Jinja expression, in your case:

environment: "{{ application_variables | items2dict }}"

Then you have the choice to:

either add the HTTP proxy variable to your application_variables list:

application_variables:
  - key: http_proxy
    value: http://proxy.example.com:8080
  - key: NODE_ENV
    value: production
  - key: PORT
    value: 3000

or combine the dictionary created from the application_variables with a variable defined at the in your playbook:

- hosts: testing

  environment: >-
    {{ 
      default_env | combine(
        application_variables | items2dict
      )
    }}
  vars:
    default_env:
      http_proxy: http://proxy.example.com:8080

As an example, the playbook:

- hosts: localhost
  gather_facts: true

  environment: >-
    {{ 
      default_env | combine(
        application_variables | items2dict
      ) 
    }}
  vars_files: config.yml
  vars:
    default_env:
      http_proxy: http://proxy.example.com:8080

  tasks:
    - debug:
        msg:
          http_proxy: "{{ ansible_facts.env.http_proxy }}"
          NODE_ENV: "{{ ansible_facts.env.NODE_ENV }}"

Would give you:

ok: [localhost] => 
  msg:
    NODE_ENV: production
    http_proxy: http://proxy.example.com:8080