Packer 係 Vagrant 作者 Mitchell Hashimoto 的另一套作品，幫助人們在不同平台上建置相同的 machine image 或 container，可視作是 Continuous Integration 乃至Continuous Delivery 的起始點，亦是 Infrastructure-as-Code 中靠近圓心的一環。 本次分享將介紹 Packer 的適用情境，使用方法，以及 SPN 整合 Packer 進 CI/CD 的哲學與理念。

1. Packer, where DevOps begins
Jeff Hung

2. @jeffhung
• github.com/jeffhung
• Works in Trend Micro
– Hadoop infrastructure
– Platform as-a Service
• Experience
– Runs agile/scrum 5 years
– Runs DevOps 2 years

3. What is DevOps?

4. DevOps 是一種 92 共識，
認真就輸了。(誤?!)

5. Dev ♥ Ops
Continuous
Integration / Delivery
Forever Stack
DevOps could be…

6. Release Early, Release Often
Fast Iteration

7. Forever Stack Tools
Jenkin
s New Relic
Gangli
a
Nagios
Cacti
Gradle
Ant
Solan
o
Chef
Ansible
Puppet
SaltStack
Logstash
Splunk
PaperTrial
NoSQL
Balsamiq
IaaS, PaaS
Docker
Selenium
Every software runs on
Operating System

9. Packer Workflow
Build Provision
Post-
Process
AWS EC2
VMware
VirtualBox
Docker
…
packer.jso
n

10. Packer Workflow
Build Provision
Post-
Process
AWS EC2
VMware
VirtualBox
Docker
…
packer.jso
n

11. packer.json
{
"variables": {
"aws_access_key": "{{env `AWS_ACCESS_KEY`}}",
"aws_secret_key”: "{{env `AWS_SECRET_KEY`}}"
},
"builders": [{
"type": "amazon-ebs",
"access_key": "{{user `aws_access_key`}}",
"secret_key": "{{user `aws_secret_key`}}",
"region”: "us-east-1",
"source_ami": "ami-9eaa1cf6",
"instance_type": "t2.micro",
"ssh_username": "ubuntu",
"ami_name": "packer-example {{timestamp}}"
}]
}
The variables
section
The builders
section

12. The variables section
{
"variables": {
"aws_access_key": "{{env `AWS_ACCESS_KEY`}}",
"aws_secret_key”: "{{env `AWS_SECRET_KEY`}}"
},
"builders": [{
"type": "amazon-ebs",
"access_key": "{{user `aws_access_key`}}",
"secret_key": "{{user `aws_secret_key`}}",
"region”: "us-east-1",
"source_ami": "ami-9eaa1cf6",
"instance_type": "t2.micro",
"ssh_username": "ubuntu",
"ami_name": "packer-example {{timestamp}}"
}]
}
User
Variables
Calls the user function to get
value
Calls the env function to get
value from environment
variables.
The env function is only
valid within the variables
section.

13. The builders section
{
"variables": {
"aws_access_key": "{{env `AWS_ACCESS_KEY`}}",
"aws_secret_key”: "{{env `AWS_SECRET_KEY`}}"
},
"builders": [{
"type": "amazon-ebs",
"access_key": "{{user `aws_access_key`}}",
"secret_key": "{{user `aws_secret_key`}}",
"region”: "us-east-1",
"source_ami": "ami-9eaa1cf6",
"instance_type": "t2.micro",
"ssh_username": "ubuntu",
"ami_name": "packer-example {{timestamp}}"
}]
}
Creates EBS-backed AMI by launching a source
AMI and re-packaging it into a new AMI after
provisioning.
The source
AMI
Use timestamp function to make it
unique
The resulting
AMI

14. $ packer build -var 'aws_access_key=YOUR ACCESS KEY'
-var 'aws_secret_key=YOUR SECRET KEY'
packer.json
==> amazon-ebs: amazon-ebs output will be in this color.
==> amazon-ebs: Creating temporary keypair for this instance...
==> amazon-ebs: Creating temporary security group for this instance...
==> amazon-ebs: Authorizing SSH access on the temporary security group...
==> amazon-ebs: Launching a secure AWS instance...
==> amazon-ebs: Waiting for instance to become ready...
==> amazon-ebs: Connecting to the instance via SSH...
==> amazon-ebs: Stopping the source instance...
==> amazon-ebs: Waiting for the instance to stop...
==> amazon-ebs: Creating the AMI: packer-example 1371856345
==> amazon-ebs: AMI: ami-19601070
==> amazon-ebs: Waiting for AMI to become ready...
==> amazon-ebs: Terminating the source AMI instance...
==> amazon-ebs: Deleting temporary security group...
==> amazon-ebs: Deleting temporary keypair...
==> amazon-ebs: Build finished.
==> Builds finished. The artifacts of successful builds are:
--> amazon-ebs: AMIs were created:
us-east-1: ami-19601070

15. Builders
• Amazon EC2 (AMI)
• DigitalOcean
• Docker
• Google Compute Engine
(GCE)
• OpenStack
• Parallels
• QEMU
• VirtualBox
• VMware
Builders are responsible for creating
machines and generating images from them
for various platforms.

16. Packer Workflow
Build Provision
Post-
Process
AWS EC2
VMware
VirtualBox
Docker
…
packer.jso
n

17. Customize with provisioners
{
"variables": {…},
"builders": […],
"provisioners": [{
"type": "shell",
"script": "./scripts/install-puppet.sh”
}, {
"type": ”puppet-masterless",
"manifest_file": "puppet/manifest/site.pp",
"module_paths": [ "puppet/modules" ],
"hiera_config_path": "puppet/hiera.yaml”
}]
}
Provisioners
are executed
one by one.
1
2

18. Install puppet agent
{
"variables": {…},
"builders": […],
"provisioners": [{
"type": "shell",
"script": "./scripts/install-puppet.sh”
}, {
"type": ”puppet-masterless",
"manifest_file": "puppet/manifest/site.pp",
"module_paths": [ "puppet/modules" ],
"hiera_config_path": "puppet/hiera.yaml”
}]
}
Provision machines using shell
scripts
Usually we will reuse these
scripts in different kinds of
machines.

19. Provision with puppet scripts
{
"variables": {…},
"builders": […],
"provisioners": [{
"type": "shell",
"script": "./scripts/install-puppet.sh”
}, {
"type": ”puppet-masterless",
"manifest_file": "puppet/manifest/site.pp",
"module_paths": [ "puppet/modules" ],
"hiera_config_path": "puppet/hiera.yaml”
}]
}
No need for a puppet
server
Manifests, modules, and hiera data can all be stored
in git.

20. Provisioners
Templates to install and configure software
within running machines prior to turning
them into machine images.
• Remote Shell
• Local Shell
• File Uploads
• PowerShell
• Windows Shell
• Ansible
• Chef Client/Solo
• Puppet Masterless/Server
• Salt
• Windows Restart

21. Packer Workflow
Build Provision
Post-
Process
AWS EC2
VMware
VirtualBox
Docker
…
packer.jso
n

22. Local Repository
Packaging and Publishing
After the machine is built, we would like to:
• Package as a zip-ball for local use
• Package as Vagrant Box and publish on Atlas
• Preserve Vagrant Box in Local
Machin
e Built
Compres
s
Package Publish Atlas
Foo.zip Foo.box

23. { …
"post-processors": [{
"type": "compress",
"output": "{{.BuildName}}-{{isotime "20060102"}}.zip"
}, [{
"type": "vagrant",
"output": "{{.BuildName}}-{{isotime "20060102"}}.box"
}, {
"type": "atlas",
"token": "{{user `atlas_token`}}",
"artifact": "trendmicro/centos62",
"artifact_type": "virtualbox",
"keep_input_artifact": true
}]]
}
Post-Processor Chains
Package as a zip-
ball for local use
Package as Vagrant
Box and publish on
Atlas

24. { …
"post-processors": [{
"type": "compress",
"output": "{{.BuildName}}-{{isotime "20060102"}}.zip"
}, [{
"type": "vagrant",
"output": "{{.BuildName}}-{{isotime "20060102"}}.box"
}, {
"type": "atlas",
"token": "{{user `atlas_token`}}",
"artifact": "trendmicro/centos62",
"artifact_type": "virtualbox",
"keep_input_artifact": true
}]]
}
Compress into Single Archive
Go-style date
format
Compression format auto-inferred from
extension

25. { …
"post-processors": [{
"type": "compress",
"output": "{{.BuildName}}-{{isotime "20060102"}}.zip"
}, [{
"type": "vagrant",
"output": "{{.BuildName}}-{{isotime "20060102"}}.box"
}, {
"type": "atlas",
"token": "{{user `atlas_token`}}",
"artifact": "trendmicro/centos62",
"artifact_type": "virtualbox",
"keep_input_artifact": true
}]]
}
Sequence
definition
Publish Vagrant Box
Preserve the vagrant
box packaged in
previous step
Preserve
Vagrant Box in
Local

26. Post-Processors
The post-processor section configures any
post-processing that will be done to image
built by the builders.
• compress
• vSphere
• Vagrant
• Vagrant Cloud
• Atlas
• docker-import
• docker-push
• docker-save
• docker-tag

27. What Else Do You Need?
• Kickstart
– Use kickstart file to install Linux from ISO
• chef/bento
– Vagrant Box Packer definitions by Chef
– Published on Atlas:
https://atlas.hashicorp.com/chef
• Windows
– Windows Automated Installation Kit (AIK)
– Unattended Windows Setup

28. Pets Cattles
Pets vs. Cattles
• Ticket-based
• Handcrafted
• Scale-up
• Smart
Hardware
• Self-Service
• Automated
• Scale-out
• Smart Apps

29. Jenkins
Cattles Workflow
Base.jso
n
Std.json
Win.json
Code
Dev
Dev.box
YUM repo
RPM
Web.jso
n
App.json
…
DB.json
Image repo
Web.box
App.box
…
DB.box
Win7.bo
x
…
Win8.bo
x
AWS
Build
RPM
Build
Imag
e
Deploy
App
Tower
Playbook

30. Jenkins
SPN (Pets) Flow
Base.jso
n
Std.json
Win.json
Code
Dev
Dev.box
YUM repo
RPM
Win7.bo
x
…
Win8.bo
x
DC /
AWS
Build
RPM
Deploy
App
Puppet
Manifest
To Docker
or not?

31. What is Your Flow?
• You need to define your DevOps flow
• No need to build Rome in one day
• Consider company culture
• Tool adoption

32. Summary
• DevOps  Fast Iteration
• Packer as the starting point
• Builders  Provisioners  Post-
Processors
• Pets or Cattle?
• Define Your DevOps Workflow

33. THANK YOU!

34. Alternative Format?
But we needs comments to add annotations
and disable entire experimental blocks...
It is one of the primary reason we choose
JSON as the configuration format: it is highly
convenient to write a script to generate the
configuration.
@mitchellh
.SUFFIXES: .json .yml
.yml.json:
ruby -ryaml -rjson
-e 'puts JSON.pretty_generate(YAML.load(ARGF))'
< $< > $@;
https://github.com/mitchellh/packer/issues/
887