• Website: https://www.packer.io
• IRC: #packer-tool on Freenode
• Mailing list: Google Groups

Packer is a tool for building identical machine images for multiple platforms from a single source configuration.

Packer is lightweight, runs on every major operating system, and is highly performant, creating machine images for multiple platforms in parallel. Packer comes out of the box with support for creating AMIs (EC2), VMware images, and VirtualBox images. Support for more platforms can be added via plugins.

The images that Packer creates can easily be turned into Vagrant boxes.

Note: There is a great introduction and getting started guide for those with a bit more patience. Otherwise, the quick start below will get you up and running quickly, at the sacrifice of not explaining some key points.

First, download a pre-built Packer binary for your operating system or compile Packer yourself.

After Packer is installed, create your first template, which tells Packer what platforms to build images for and how you want to build them. In our case, we'll create a simple AMI that has Redis pre-installed. Save this file as quick-start.json. Be sure to replace any credentials with your own.

{
  "builders": [{
    "type": "amazon-ebs",
    "access_key": "YOUR KEY HERE",
    "secret_key": "YOUR SECRET KEY HERE",
    "region": "us-east-1",
    "source_ami": "ami-de0d9eb7",
    "instance_type": "t1.micro",
    "ssh_username": "ubuntu",
    "ami_name": "packer-example {{timestamp}}"
  }]
}

Next, tell Packer to build the image:

$ packer build quick-start.json
...

Packer will build an AMI according to the "quick-start" template. The AMI will be available in your AWS account. To delete the AMI, you must manually delete it using the AWS console. Packer builds your images, it does not manage their lifecycle. Where they go, how they're run, etc. is up to you.

Full, comprehensive documentation is viewable on the Packer website:

https://www.packer.io/docs

If you wish to work on Packer itself, you'll first need Go installed (version 1.2+ is required). Make sure you have Go properly installed, including setting up your GOPATH.

For some additional dependencies, Go needs Mercurial and Bazaar to be installed. Packer itself doesn't require these, but a dependency of a dependency does.

You'll also need gox to compile packer. You can install that with:

$ go get -u github.com/mitchellh/gox

Next, clone this repository into $GOPATH/src/github.com/mitchellh/packer and then just type make. In a few moments, you'll have a working packer executable:

$ make
...
$ bin/packer
...

You can run tests by typing make test.

This will run tests for Packer core along with all the core builders and commands and such that come with Packer.

If you make any changes to the code, run make format in order to automatically format the code according to Go standards.

When new dependencies are added to packer you can use make updatedeps to get the latest and subsequently use make to compile and generate the packer binary.