Ansible is a Configuration Management System that is very simple to use, because of its straightforward and robust model for managing automation and it’s low barrier to entry for ease of use in both development and production. During OpenStack development, Ansible can be used in conjunction with Vagrant and Devstack to manage complex, multi-node development environments with relative ease. In this presentation, Juergen Brendel and David Lapsley review Ansible and provide some sample playbooks to get developers up and running quickly. They also describes how to use Ansible, Vagrant, Devstack, and OpenStack to accelerate OpenStack development cycles.

1. OpenStack Vancouver Summit
Learn you some Ansible for Great Good!
Juergen Brendel (@brendelconsult) , David Lapsley (@devlaps)
May 21, 2015

2. Unified test and deployment
environments

3. Dev, Test, Deploy

4. Dev, Test, Deploy
Why didn't we
catch this bug
in testing?

5. Dev, Test, Deploy
Why didn't we
catch this bug
in testing?
We can't
reproduce the
issues.

6. Dev, Test, Deploy
Why didn't we
catch this bug
in testing?
We can't
reproduce the
issues.
I don't have
access to our
test server.

7. Dev, Test, Deploy
Why didn't we
catch this bug
in testing?
How do I setup
my
development
environment?
We can't
reproduce the
issues.
I don't have
access to our
test server.

8. Dev, Test, Deploy
Why didn't we
catch this bug
in testing?
How do I setup
my
development
environment?
We can't
reproduce the
issues.
I don't have
access to our
test server.
“It works for me...”
(shrug)

9. Dev, Test, Deploy
Why didn't we
catch this bug
in testing?
How do I setup
my
development
environment?
We can't
reproduce the
issues.
I don't have
access to our
test server.
“It works for me...”
(shrug)Wouldn't this be nice instead?
Single command: Dev environment created
Single command: Test environment created

10. Summary

11. • Configuration management background
• Ansible introduction
• Rise of APIs
• Unified test and deployment environments
• Demonstration

12. Configuration Management
Tools
Overview

13. Configuring servers
How do you configure a server?

14. Arcane
magic
Configuring servers
How do you configure a server?

15. Arcane
magic
Configuring servers
How do you configure a server?
Manual
instructions

16. Arcane
magic
Configuring servers
How do you configure a server?
Manual
instructions
Scripts

17. Arcane
magic
Configuring servers
How do you configure a server?
Manual
instructions
Scripts
CM tools

18. Arcane
magic
Configuring servers
How do you configure a server?
Manual
instructions
Scripts
CM tools
Automation!

19. CM Tools
Describe the desired state

20. Ensure all
system packages
are updated.
CM Tools
Describe the desired state

21. Ensure all
system packages
are updated.
CM Tools
Describe the desired state
Ensure package
“apache” is
installed.

22. Ensure all
system packages
are updated.
CM Tools
Describe the desired state
Ensure that user
“xyz” exists.
Ensure package
“apache” is
installed.

23. Ensure all
system packages
are updated.
CM Tools
Describe the desired state
Ensure that user
“xyz” exists.
Ensure package
“apache” is
installed.
Have latest
sources: Clone
repo, update if it
exists already.

24. Ensure all
system packages
are updated.
CM Tools
Describe the desired state
Ensure that user
“xyz” exists.
Ensure package
“apache” is
installed.
Have latest
sources: Clone
repo, update if it
exists already.
Ensure package
“postgres” v9.1 is
installed.

25. Ensure all
system packages
are updated.
CM Tools
Describe the desired state
Ensure that user
“xyz” exists.
Ensure package
“apache” is
installed.
Have latest
sources: Clone
repo, update if it
exists already.
Ensure package
“postgres” v9.1 is
installed. Ensure DB
“app_data” exists
with password
“****”.

26. Configuration Management
Tools
Varieties

27. Puppet (2005)
“powerful, feature-rich, enterprise-y”
Chef (2009)
CM Tools variety

28. Puppet (2005)
“powerful, feature-rich, enterprise-y”
Chef (2009)
Salt (2011)
“simple, fast, good for most things”
Ansible (2012)
CM Tools variety

29. Puppet (2005)
“powerful, feature-rich, enterprise-y”
Chef (2009)
Salt (2011)
“simple, fast, good for most things”
Ansible (2012)
Fabric (2011)
“not really CMS tools”
Scripts
CM Tools variety

30. Ansible Overview

31. • “Orchestration engine” for CM and deployment
• Written in Python
• Uses YAML
• “Playbooks”
• Config specs or explicit commands
Ansible overview

32. • Key Points:
• No central configuration server
• No key management
• No agent to install on target machine
• Explicit order
Ansible simplicity

33. • Key Points:
• No central configuration server
• No key management
• No agent to install on target machine
• Explicit order
• Requirements:
• Need SSH access (with key or password)
• Need Python installed on target machine
Ansible simplicity

34. Ansible architecture
Server 1
Server 2
Server 3
Server 4
Server 5
Your laptop

35. Ansible Overview
Modules

36. Modules
Hundreds of them. They know how to do stuff…
Command
Shell
Script

37. Modules
Hundreds of them. They know how to do stuff…
Command
Shell
Script
Copy
Sync
Templates
Line ops

38. Modules
Hundreds of them. They know how to do stuff…
Command
Shell
Script
Copy
Sync
Templates
Line ops
Install packages
Users and groups
Networking
Services

39. Modules
Hundreds of them. They know how to do stuff…
Command
Shell
Script
Copy
Sync
Templates
Line ops
Install packages
Users and groups
Networking
Services
Repositories
Message queues
Monitoring
Notification

40. Modules
Hundreds of them. They know how to do stuff…
Command
Shell
Script
Copy
Sync
Templates
Line ops
Install packages
Users and groups
Networking
Services
Repositories
Message queues
Monitoring
Notification
Web servers
Database servers
Cloud infra

41. Ansible Overview
How does it
work?

42. How does it work?
Laptop

43. How does it work?
Python Module
“Install Apache”
Laptop
run playbook

44. How does it work?
Python Module
“Install Apache”
Run ModuleLaptop
ssh

45. How does it work?
Python Module
“Install Apache”
Run Module
(then delete)
Run ModuleLaptop
ssh

46. How does it work?
Python Module
“Install Apache”
Run Module
(then delete)
Run ModuleLaptop
return results

47. Ansible Overview
Details

48. Inventory and groups
Define hosts, organized in groups

49. Inventory and groups
Define hosts, organized in groups
 by function
 by location
 by hosting provider
 ...

50. [europe]
server1.somehoster.co.uk
server2.otherhoster.de
[north-america]
host-a.serverhost.com
host-b.serverhost.com
[frontend]
server1.somehoster.co.uk
host-b.serverhost.com
[backend]
server2.otherhoster.de
host-a.serverhost.com

51. Adhoc commands
Single commands, applied to groups

52. Adhoc commands
Single commands, applied to groups
$ ansible -i hosts europe –a “uname -a”
$ ansible -i hosts frontend -a “/sbin/reboot” -f 3

53. • Tell Ansible what to do
Playbooks

54. ---
- hosts: frontend
sudo: yes
tasks:
- name: Update the system
apt: pkg=nginx state=latest
- name: Create the user account
user: name=appuser shell=/bin/bash state=present
- name: Copy files to remote user's home
copy: >
src=files/names.txt dst=/home/appuser
owner=appuser mode=0644

55. • Provide input to Ansible templates
Variables

56. ---
- hosts: all
sudo: yes
vars:
username: appuser
tasks:
- name: Create the user account
user: >
name={{ username }}
shell=/bin/bash
state=present

57. • Simple layout for arranging Ansible playbooks, variables,
templates, metadata, etc.
Simple Project Layout

58. /
my_hosts
group_vars/
all
frontend
backend
europe
north-america
site.yml

59. • Best practices layout for arranging Ansible playbooks,
variables, templates, metadata, etc.
• Better suited for larger projects
• More extensible
Best Practice Project Layout

60. /
ansible.cfg
deploy_hosts
staging_hosts
group_vars/
all
frontend
backend
europe
north-america
host_vars/
server1.somehoster.co.uk
host-b.serverhost.com
site.yml
roles/
common/
tasks/
main.yml
handlers/
main.yml
templates/
sshd_config.j2
files/
my_script.sh
vars/
main.yml
web/
...
db/
...

61. Playbooks with roles
---
- hosts: frontend
sudo: yes
roles:
- common
- web

62. The rise and rise of APIs

63. The rise and rise of APIs
APIs

64. The rise and rise of APIs
APIs
Local

65. The rise and rise of APIs
APIs
Local Infrastructure

66. The rise and rise of APIs
APIs
Local Infrastructure Services

67. The rise and rise of APIs
APIs
Local Infrastructure Services

68. Ansible 'cloud' modules
Public cloud
 OpenStack
 Amazon AWS
 Google Compute
 Azure
 Digital Ocean
 Linode
Private cloud
• OpenStack
• Eucalyptus
• Vsphere
• Docker
• libvirt

69. Example: AWS Modules
EC2 / infrastructure
• Instances
• Images
• VPCs
• Load balancers
Services
• S3
• Route 53
• Databases
• Cache

70. • Create instances via AWS and OpenStack
Example: Create instances

71. - name: Booting EC2 guests
ec2:
key_name: my-key
group: my-security-group
instance_type: t2.micro
image: ami-120abc90
region: us-east-1
count: 1
register: ec2results

72. - name: Booting OpenStack guests
nova_compute:
state: present
login_username: "{{ openstack_username }}"
login_password: "{{ openstack_password }}"
login_tenant_name: "{{ openstack_tenantname }}"
name: "{{ cluster_id }}-{{ item }}"
image_id: "{{ openstack_image_id }}"
key_name: "{{ openstack_keyname }}"
wait_for: 60
flavor_id: "{{ openstack_flavor_id }}"
nics:
- net-id: "{{ openstack_internal_net_id }}”
register: openstack_guests

73. • Add hosts to inventory
Example: Create instances

74. - local_action:
module: ec2
key_name: my-key
group: my-security-group
instance_type: t2.micro
image: ami-120abc90
region: us-east-1
count: 3
register: ec2results
- local_action:
module: add_host
hostname: {{ item.public_ip }}
groupname: my-server-group
with_items: ec2results.instances

75. Unified test and deployment
environments
Vagrant

76.  Use Vagrant to spin-up VMs
 local (VirtualBox, VMware, etc.)
 cloud (EC2)
 Use Ansible as 'provisioner'
 Make an inventory file with just your VM
 Point at same playbook as before
Vagrant

77. • Tells vagrant which VMs to construct
• How to construct them:
• RAM
• Virtual CPUs
• Network interfaces (public, private, static, nat’d)
Vagrant config: Vagrantfile

78. Vagrant.configure(2) do |config|
config.vm.box = "saucy64"
config.vm.box_url = "http://cloud-
images.ubuntu.com/vagrant/..."
config.vm.host_name = "myapp-test"
config.vm.network "private_network", ip: "192.168.1.2”
config.vm.provision "ansible" do |ansible|
ansible.playbook = "site.yml"
#ansible.verbose = "vvvv"
ansible.inventory_path = "vagrant_hosts"
ansible.host_key_checking= false
end
end

79. • Specifies which VMs/Groups Ansible should run against
Inventory: Vagrant Hosts

80. [vagrant]
vagrant_host
ansible_ssh_host=192.168.1.2
[frontend-hosts]
vagrant_host
[applayer-hosts]
vagrant_host
[backend-hosts]
vagrant_host
[db-access:children]
applayer-hosts
backend-hosts
[appserver-access:children]
frontend-hosts
applayer-hosts

81. Vars: group_vars/vagrant
Variables that only apply to Vagrant instances
---
ansible_ssh_user: vagrant

82. Create and configure VMs
$ vagrant up
...
$ vagrant provision

83. Unified test and deployment
environments
Cattle, not
pets!

84. Desired development/deployment workflow
- Local unit tests
- Local provisioning with Vagrant + Ansible
- Integration tests
Local dev
and testing

85. Desired development/deployment workflow
- Create/update cloud
staging servers with
Ansible
- Provision servers with
Ansible
Local dev
and testing
Cloud
testing

86. Desired development/deployment workflow
- Create/update cloud production
servers with Ansible
- Provision servers with Ansible
Local dev
and testing
Cloud
testing
Cloud deployment

87. Demo

88. Dev Environment
Cacher (apt/pip)
MCP MHV1 MHV2
Ansible
Git cache

89. • Same Ansible playbooks can be used to provision
application locally or in the cloud
Key Takeaways

90. • Same Ansible playbooks can be used to provision
application locally or in the cloud
• With cloud APIs and Ansible modules (OpenStack, AWS,
Rackspace, …) playbooks can also be used to provision
infrastructure
Key Takeaways

91. References

92. • Questions: jbrendel@cisco.com, dlapsley@cisco.com
• Ansible playbooks: http://bit.ly/devstack-ansible
• Ansible docs: http://docs.ansible.com/
• Ansible source: https://github.com/ansible/ansible
• Vagrant: http://www.vagrantup.com/
• Example project: http://bit.ly/ansible-devstack

93. @brendelconsult, @devlaps
Thank You