packer-docker-chef-ubuntu

Example repository showing how to make a packer template which builds ubuntu images with chef and docker installed. The goal of this repository is to capture all the learnings about the best way to perform basic infrastructure builds, so pull requests are most welcome.

Details

In order to build instance store backed images you will need the your AWS credentials. Also, because packer is still using the old AWS command line utilities you will need to generate and use X.509 keys. This is tracked and will hopefully be fixed soon.

There are a number of ways you can shoot yourself in the foot while making images and this repository avoids all the ones I know about. Since there is no good way to put comments in a json file, I feel compelled to point out the inclusion of the shutdown_command for the vagrant builder. Packer does not currently warn if you do not have a command there, but without it you will not be able to make an image.

There is a known bug with vagrant post-processors for instance images which prevents them from being run, which is why they are disabled.

Since image names need to be unique, I use a timestamp suffix. You may want to use something more meaningful.

The traditional EC2 command line tools have a number of very sharp edges around building instance store images, the most notable of which is that by default they remove all .pem and .gpg files from the image being built, which effectively causes the images to be unable to authenticate a secure SSL connection. This is the reason for the custom bundle_vol_command which uses --no-filter and excludes /tmp, where keys are uploaded, directly.

As you experiment in building images, you will probably find it helpful to set the PACKER_CACHE environment variable so that you can avoid downloading the same large ISO images multiple times.

Configuration

The packer template needs the following variables to be specified

• aws_region The region to launch and store the image in. Defaults to us-west-1 because that is what I use.

• aws_s3_bucket The name of the S3 bucket into which your image is stored cannot contain periods or be DNS like.

• aws_access_key The AWS access key for provisioning. You probably want to keep this out of your git history.

• aws_secret_key The AWS secret key for provisioning. You probably want to keep this out of your git history.

• aws_account_id The AWS account ID for provisioning.

• aws_x509_cert_path Path to an X.509 signing cert

• aws_x509_key_path Path to an X.509 private key

Building

When you are building the images you need to supply the aws_* variables. You can do this individually on the command line, or put them all in a file, which is what I do to make my life easier.

Caveats

The image created here has not been security hardened or audited in any way. If you are using this for anything other than an example you almost certainly want to lock the system down. There are a number of good starting points for securing a sever.