Reload Ansible's dynamic inventory
I'm using Ansible to setup EC2 instances and deploy an app. There's a hosts script which gathers tags related servers and groups info. I'd like to run these actions as a single playbook, so
- New instances are created if needed
- Hosts script loads inventory (including servers' facts)
- Deployment playbook works
However, inventory loaded in advance so there is no servers/groups data if servers created/updated during the play. I can 1) separate provision and deployment playbooks 2) use add_host trick to emulate dynamic inventory when servers are updated, but there are drawbacks in those approaches.
Can I force Ansible to reload inventory? My test files are:
hosts
script:
#!/bin/sh
echo `date` >> log.log
echo "{\"standalone\":[\"localhost\"]}"
Sample playbook.yml
:
---
- hosts: all
tasks:
- name: show inventory_hostname
command: echo {{ inventory_hostname }}
I run it ansible-playbook -i hosts playbook.yml -v
and see two runs:
$> cat log.log
Thu Mar 12 09:43:16 SAMT 2015
Thu Mar 12 09:43:16 SAMT 2015
but I haven't found a command to double it.
With Ansible 2.0+, you can refresh your inventory mid-play by running the task:
- meta: refresh_inventory
I found the meta: refresh_inventory
to be insufficient.
I had to add an explicit call to ec2.py --refresh-cache
first.
- name: refresh inventory hosts: localhost connection: local gather_facts: False tasks: - name: Refresh EC2 cache command: /etc/ansible/ec2.py --refresh-cache - name: Refresh in-memory EC2 cache meta: refresh_inventory
Ansible currently doesn't support this. If you look at the source code of the ansible
or ansible-playbook
commands you'll see that the inventory is loaded first and then the inventory object is passed to the ansible command that runs the specified task or playbook. Moving the inventory processing so that it happens within the task/playbook handlers would probably be a pretty major undertaking for a number of reasons.
Your best bet when doing something like this is to simply break your playbook into two and wrap their calls in a shell script that you only have to invoke once.
You can also edit the ec2.ini file and set the option:
cache_max_age = 0
to prevent the need for reload by making sure that nothing is cached in the first place.