Pass a parameter to Ansible's dynamic inventory

Question

I'm using Ansible to configure some virtual machines. I wrote a Python script which retrieves the hosts from a REST service.
My VMs are organized in "Environments". For example I have the "Test", "Red" and "Integration" environments, each with a subset of VMs.

This Python script requires the custom --environment <ENV> parameter to retrieve the hosts of the wanted environment.

The problem I'm having is passing the <ENV> to the ansible-playbook command. In fact the following command doesn't work

ansible-playbook thePlaybook.yml -i ./inventory/FromREST.py --environment Test

I get the error:

Usage: ansible-playbook playbook.yml

ansible-playbook: error: no such option: --environment

What is the right syntax to pass variables to a dynamic inventory script?

Update:

To better explain, the FromREST.py script accepts the following parameters:

• Either the --list parameter or the --host <HOST> parameter, as per the Dynamic Inventory guidelines
• The --environment <ENVIRONMENT> parameter, which I added to the ones required by Ansible to manage the different Environments

Answer 1

I had similar issue, I didn't find any solution, so I just modified my dynamic inventory to use OS Environment variable if the user does not pass --env

Capture env var in your inventory as below:

import os
print os.environ['ENV']

Pass env var to ansible

export ENV=dev
ansible -i my_custom_inv.py all --list-host

Answer 2

A workaround using $PPID to parse -e/--extra-vars from process snapshot.

ansible-playbook -i inventory.sh deploy.yml -e cluster=cl_01

inventory.sh file

#!/bin/bash
if [[ $1 != "--list" ]]; then exit 1; fi
extra_var=`ps -f -p $PPID | grep ansible-playbook | grep -oh "\w*=\w*" | grep cluster | cut -f2 -d=`
./inventory.py --cluster $extra_var

inventory.py returns JSON inventory for cluster cl_01.

Not pretty I know, but works.