Best way to launch aws ec2 instances with ansible - amazon-web-services

Question

I'm trying to create an small webapp infrastructure with ansible on Amazon AWS and I want to do all the process: launch instance, configure services, etc. but I can't find a proper tool or module to deal with that from ansible. Mainly EC2 Launch.
Thanks a lot.

Answer 1

This is the short answer of your question, if you want detail and fully automated role, please let me know. Thanks
Prerequisite:
Ansible
Python boto library
Set up the AWS access and secret keys in the environment settings
(best is inside the ~./boto)
To Create the EC2 Instance(s):
In order to create the EC2 Instance, please modified these parameters that you can find inside the "ec2_launch.yml" file under "vars":
region # where is want to launch the instance(s), USA, Australia, Ireland etc
count # Number of instance(s), you want to create
Once, you have mentioned these parameter, please run the following command:
ansible-playbook -i hosts ec2_launch.yml
Contents of hosts file:
[local]
localhost
[webserver]
Contents of ec2_launch.yml file:
---
- name: Provision an EC2 Instance
hosts: local
connection: local
gather_facts: False
tags: provisioning
# Necessary Variables for creating/provisioning the EC2 Instance
vars:
instance_type: t1.micro
security_group: webserver # Change the security group name here
image: ami-98aa1cf0 # Change the AMI, from which you want to launch the server
region: us-east-1 # Change the Region
keypair: ansible # Change the keypair name
count: 1
# Task that will be used to Launch/Create an EC2 Instance
tasks:
- name: Create a security group
local_action:
module: ec2_group
name: "{{ security_group }}"
description: Security Group for webserver Servers
region: "{{ region }}"
rules:
- proto: tcp
type: ssh
from_port: 22
to_port: 22
cidr_ip: 0.0.0.0/0
- proto: tcp
from_port: 80
to_port: 80
cidr_ip: 0.0.0.0/0
rules_egress:
- proto: all
type: all
cidr_ip: 0.0.0.0/0
- name: Launch the new EC2 Instance
local_action: ec2
group={{ security_group }}
instance_type={{ instance_type}}
image={{ image }}
wait=true
region={{ region }}
keypair={{ keypair }}
count={{count}}
register: ec2
- name: Add the newly created EC2 instance(s) to the local host group (located inside the directory)
local_action: lineinfile
dest="./hosts"
regexp={{ item.public_ip }}
insertafter="[webserver]" line={{ item.public_ip }}
with_items: "{{ ec2.instances }}"
- name: Wait for SSH to come up
local_action: wait_for
host={{ item.public_ip }}
port=22
state=started
with_items: "{{ ec2.instances }}"
- name: Add tag to Instance(s)
local_action: ec2_tag resource={{ item.id }} region={{ region }} state=present
with_items: "{{ ec2.instances }}"
args:
tags:
Name: webserver

Answer 2

As others have said, the cloud module contains just about all the AWS provisioning support you'd need. That said, Ansible's paradigm makes most sense once there's an existing SSH:able machine to target and connect to. The instantiation phase, by comparison, essentially asks you to target your local machine and calls AWS API endpoints from there.
Like you, I wanted a single-shot command with a graceful transition from EC2 instantiation into its configuration. There's suggestions on how to accomplish something like this in the documentation, but it relies on the the add_host module to tweak Ansible's idea of current host inventory, and even then I couldn't find a solution that didn't feel like i was working against rather than with the system.
In the end I opted for two distinct playbooks: a provision.yml that uses the ec2, ec2_group, ec2_vol, ec2_eip and route53 modules to ensure I have the "hardware" in place, and then configure.yml, more like a traditional Ansible site.yml, which is able to treat host inventory (static in my case, but dynamic will work well) as a given and do all that good declarative state transitioning.
Both playbooks are idempotent, but it's configure.yml that's meant to be rerun over and over in the long run.

Answer 3

The EC2 module was designed precisely for creating and destroying instances.
If you want the "best" way, it's hard to beat CloudFormation, which can be launched from Ansible.