Ansible Dynamic Inventory fails to get the latest ec2 information - amazon-web-services

Question

I am using ec2.py dynamic inventory for provisioning with ansible.
I have placed the ec2.py in /etc/ansible/hosts file and marked it executable.
I also have the ec2.ini file in /etc/ansible/hosts.
[ec2]
regions = us-west-2
regions_exclude = us-gov-west-1,cn-north-1
destination_variable = public_dns_name
vpc_destination_variable = ip_address
route53 = False
all_instances = True
all_rds_instances = False
cache_path = ~/.ansible/tmp
cache_max_age = 0
nested_groups = False
group_by_instance_id = True
group_by_region = True
group_by_availability_zone = True
group_by_ami_id = True
group_by_instance_type = True
group_by_key_pair = True
group_by_vpc_id = True
group_by_security_group = True
group_by_tag_keys = True
group_by_tag_none = True
group_by_route53_names = True
group_by_rds_engine = True
group_by_rds_parameter_group = True
Above is my ec2.ini file
---
- hosts: localhost
connection: local
gather_facts: yes
vars_files:
- ../group_vars/dev_vpc
- ../group_vars/dev_sg
- ../hosts_vars/ec2_info
vars:
instance_type: t2.micro
tasks:
- name: Provisioning EC2 instance
local_action:
module: ec2
region: "{{ region }}"
key_name: "{{ key }}"
instance_type: "{{ instance_type }}"
image: "{{ ami_id }}"
wait: yes
group_id: ["{{ sg_npm }}", "{{sg_ssh}}"]
vpc_subnet_id: "{{ PublicSubnet }}"
source_dest_check: false
instance_tags: '{"Name": "EC2", "Environment": "Development"}'
register: ec2
- name: associate new EIP for the instance
local_action:
module: ec2_eip
region: "{{ region }}"
instance_id: "{{ item.id }}"
with_items: ec2.instances
- name: Waiting for NPM Server to come-up
local_action:
module: wait_for
host: "{{ ec2 }}"
state: started
delay: 5
timeout: 200
- include: ec2-configure.yml
Now the configuring script is as follows
- name: Configure EC2 server
hosts: tag_Name_EC2
user: ec2-user
sudo: True
gather_facts: True
tasks:
- name: Install nodejs related packages
yum: name={{ item }} enablerepo=epel state=present
with_items:
- nodejs
- npm
However when the configure script is called, the second script results into no hosts found.
If I execute the ec2-configure.yml just alone and if the EC2 server is up & running then it is able to find it and configure it.
I added the wait_for to make sure that the instance is in running state before the ec2-configure.yml is called.
Would appreciate if anyone can point my error. Thanks

Answer 1

After researching I came to know that the dynamic inventory doesnt refresh between playbook calls, it will only refresh if you are executing the playbook seprately.
However I was able to resolve the issue by using add_host command.
- name: Add Server to inventory
local_action: add_host hostname={{ item.public_ip }} groupname=webserver
with_items: webserver.instances

Answer 2

With ansible 2.0+, you refresh the dynamic inventory in the middle of the playbook as the task like this:
- meta: refresh_inventory
To extend this a bit, If you are getting problem with the cache in your playbook, then you can use it like this:
- name: Refresh the ec2.py cache
shell: "./inventory/ec2.py --refresh-cache"
changed_when: no
- name: Refresh inventory
meta: refresh_inventory
where ./inventory is the path to your dynamic inventory, please adjust it accordingly.
Hope this will help you.

Answer 3

Configure EC2 server play can't find any hosts from EC2 dynamic inventory because the new instance was added in the first play of the playbook - during the same execution. Group tag_Name_EC2 didn't exist in the inventory when the inventory was read and thus can't be found.
When you run the same playbook again Configure EC2 server should find the group.
We have used the following workaround to guide users in this kind of situations.
First, provision the instance:
tasks:
- name: Provisioning EC2 instance
local_action:
module: ec2
...
register: ec2
Then add a new play before ec2-configure.yml. The play uses ec2 variable that was registered in Provisioning EC2 instance and will fail and exit the playbook if any instances were launched:
- name: Stop and request a re-run if any instances were launched
hosts: localhost
gather_facts: no
tasks:
- name: Stop if instances were launched
fail: msg="Re-run the playbook to load group variables from EC2 dynamic inventory for the just launched instances!"
when: ec2.changed
- include: ec2-configure.yml

Answer 4

You can also refresh the cache:
ec2.py --refresh-cache
Or if your using as the Ansible host file:
/etc/ansible/hosts --refresh-cache