Using Ansible Dynamic Inventory with Amazon EC2

Brian Schott, CTO

Nimbis Services

brian.schott@nimbisservices.com

Using Ansible Dynamic Inventory for Amazon EC2 1

Something Borrowed…

Using Ansible Dynamic Inventory for Amazon EC2 2

http://www.slideshare.net/lorinh/vagrant-ansible-and-openstack-on-your-laptop

http://www.ansible.com/ansible-book

Shell scripts are painful, Puppet & Chef have steep learning curves

if [[ $EUID -eq 0 ]]; then

ROOTSLEEP=${ROOTSLEEP:-10}

echo "You are running this script as root."

echo "In $ROOTSLEEP seconds, we will create a user 'stack' and run as that user"

sleep $ROOTSLEEP

# since this script runs as a normal user, we need to give that user

# ability to run sudo

if [[ "$os_PACKAGE" = "deb" ]]; then

dpkg -l sudo || apt_get update && install_package sudo

else

rpm -qa | grep sudo || install_package sudo

fi

if ! getent passwd stack >/dev/null; then

echo "Creating a user called stack"

useradd -U -s /bin/bash -d $DEST -m stack

fi

Source: devstack/stack.shUsing Ansible Dynamic Inventory for Amazon EC2 3

Ansible big idea: very simple syntax, SSH for communication

• Open Sourcehttps://github.com/ansible/ansible

• Agentless

• Python

• YAML

• Jinja2

• SSH

Using Ansible Dynamic Inventory for Amazon EC2 4

http://ansible.com/ansible-resources

Example Ansible playbook: install ntp

---

- hosts: controller

tasks:

- name: ensure ntp packages is installed

action: apt pkg=ntp

- name: ensure ntp.conf file is present

action: copy src=files/ntp.conf dest=/etc/ntp.conf

owner=root group=root mode=0644

- name: ensure ntp service is restarted

action: service name=ntp state=restarted

Using Ansible Dynamic Inventory for Amazon EC2 5

Specify hosts in an inventory file

[controller]

192.168.206.130

[compute]

192.168.206.131

192.168.206.132

192.168.206.133

192.168.206.134

Using Ansible Dynamic Inventory for Amazon EC2 6

Run the playbook$ ansible-playbook ntp.yaml

PLAY [controller] *********************

GATHERING FACTS *********************

ok: [192.168.206.130]

TASK: [ensure ntp packages is installed] *********************

ok: [192.168.206.130]

TASK: [ensure ntp.conf file is present] *********************

ok: [192.168.206.130]

TASK: [ensure ntp service is restarted] *********************

ok: [192.168.206.130]

PLAY RECAP *********************

192.168.206.130 : ok=4 changed=3

unreachable=0 failed=0

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What did Ansible just do?

1. Made SSH connections to remote host(s)

2. Copied over Python modules and arguments parsed from playbook file

3. Executed modules on remote machine

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Can run a single action usingansible command

$ ansible controller –m apt –a "pkg=ntp"

192.168.206.130 | success >> {

"changed": false,

"item": "",

"module": "apt"

}

Using Ansible Dynamic Inventory for Amazon EC2 9

Ansible scripts are idempotent: can run multiple times safely

$ ansible-playbook ntp.yaml

PLAY [controller] *********************

GATHERING FACTS *********************

ok: [192.168.206.130]

TASK: [ensure ntp packages is installed] *********************

ok: [192.168.206.130]

TASK: [ensure ntp.conf file is present] *********************

ok: [192.168.206.130]

TASK: [ensure ntp service is restarted] *********************

ok: [192.168.206.130]

PLAY RECAP *********************

192.168.206.130 : ok=4 changed=1unreachable=0 failed=0

Using Ansible Dynamic Inventory for Amazon EC2 10

What does Ansible have to do with cloud?

Using Ansible Dynamic Inventory for Amazon EC2 11http://docs.ansible.com/list_of_cloud_modules.html

Ansible Dynamic Inventory Feature

Using Ansible Dynamic Inventory for Amazon EC2 12

http://docs.ansible.com/intro_dynamic_inventory.html

A Practical Example

Using Ansible Dynamic Inventory for Amazon EC2 13

https://github.com/electroniceagle/ansible-dc-ec2-tutorial

AWS Free Tier

Using Ansible Dynamic Inventory for Amazon EC2 14

Ansible Galaxy (https://galaxy.ansible.com)

Using Ansible Dynamic Inventory for Amazon EC2 15

Ansible Directory Structure

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ansible.cfg

Using Ansible Dynamic Inventory for Amazon EC2 17

provision_instances.yaml

Using Ansible Dynamic Inventory for Amazon EC2 18

keypair.yaml

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securitygroup.yaml

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instance.yaml

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Provision Playbook

Using Ansible Dynamic Inventory for Amazon EC2 22

setup_instances.yaml, part 1

Using Ansible Dynamic Inventory for Amazon EC2 23

setup_instances.yaml, part 2

Using Ansible Dynamic Inventory for Amazon EC2 24

setup_instances.yaml, part 3

Using Ansible Dynamic Inventory for Amazon EC2 25

Setup Playbook

Using Ansible Dynamic Inventory for Amazon EC2 26

terminate_instances.yaml

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Terminate Playbook

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Thank You

• Brian Schott, CTONimbis Servicesbrian.schott@nimbisservices.com

• https://github.com/electroniceagle/ansible-dc-ec2-tutorialhttps://slideshare.net/bfschott

Using Ansible Dynamic Inventory for Amazon EC2 29