imgr

A Packer inspired tool written in Groovy

imgr is a tool to create Amazon EC2 AMIs (images) from a configuration file.

It is built with extensibility in mind, therefore it is easy to add new cloud providers.

Currently, it supports configuring a box via a Puppet manifest or a Shell script.

Requirements

• Java 6

Building

gradlew clean build

Tests are disabled by default. To enable the tests, use

gradlew clean build -Drun.tests=true

Installation

• Run gradlew distZip (or gradlew.bat distZip on Windows )
• An archive containing the application's runtime and script is generated in the 'build/distributions' folder
• Unzip the archive in any location

Usage

• Run bin/groovy-packer config.json to execute a configuration located in the config.json file.

Template configuration

groovy-packer configuration is based on a template written in in JSON. A template contains the various components required to build a machine image. A template has two sections:

• Builder
• Provisioner

Builders

A builder represent the description of how to start a Virtual Machine. Currently, groovy-packer only supports Amazon EC2. The Amazon builder is named amazon-ebs and has the following properties:

• type (string) the type of builder. At the moment only amazon-ebs is supported
• access_key (string) the access key used to communicate with AWS. If not specified, Packer will attempt to read this from the environmental variable AWS_ACCESS_KEY_ID
• secret_key (string) The secret key used to communicate with AWS. If not specified, Packer will attempt to read this from environmental variables AWS_SECRET_ACCESS_KEY
• region (string) The name of the region, such as "us-east-1", in which to launch the EC2 instance to create the AMI.
• source_ami (string) The AMI used to start the machine that will be configured.
• instance_type (string) The EC2 instance type used for starting the machine. For a list of valid instance types refer to the Amazon documentation.
• ssh_username (string) The username used by groovy-packer to communicate with the machine over SSH.
• ami_name (string) The name of the generated AMI. Please note that the name must be unique.
• keypair (string) The name of the key pair used to connect to your EC2 instance. This option will be removed soon
• keypair_location (string) The path to the key pair stored on the local machine This option will be removed soon
• security_group (string) The name of the security group to use for the instance This option will be removed soon

The amazon-ebs builder creates an instance which root device is backed by Amazon EBS (for more information about instance types read here.

Here is an example of a Builder:

"builders": [{
	"type": "amazon-ebs",
    "access_key": "AMAZON_1234556790",
    "secret_key": "AMAZON_SECRET_12345",
    "region": "eu-west-1",
    "source_ami": "ami-9bf6e0ef",
    "instance_type": "t1.micro",
    "ssh_username": "ec2-user",
    "ami_name": "groovy",
    "keypair": "mykeypair",
    "keypair_location":"/Users/John/.ec2/mykeypair.pem",
    "security_group": "default-security"
}]

Provisioners

The provisioners section of the template is an array of one or more objects that defines the provisioners that will be used to install and configure software for the machines created by each the builders.

At the moment there are two provisioners supported: a Shell provisioner and a Puppet provisioner.

Shell provisioner

A shell provisioner allows to configure a box either by sending an array of commands or a Shell script.

The configuration for a shell provisioner has 3 arguments:

• type (string) the provisioner type, in the case of the shell provisioner the value must be shell.
• inline (array of string) This is an array of commands to execute. The commands are concatenated by newlines and turned into a single file, so they are all executed within the same context. This allows you to change directories in one command and use something in the directory in the next and so on. Inline scripts are the easiest way to pull of simple tasks within the machine.
• script (string) The absolute path to a script to upload and execute in the machine

Here is an example of a shell provisioner:

"provisioners": [{
    "type": "shell",
    "inline": ["uname -a > uname.txt","touch test.txt"],
    "script":"/Users/john/provision/myscript.sh"
}]

Puppet provisioner

The Puppet provisioner installs and configures software on machines built by Packer using Puppet. A Puppet manifest is uploaded to the target machine and executed using puppet apply. The provisioner will even install Puppet onto your machine if it isn't already installed.

At the moment, it is possible to apply a single manifest. The configuration for the Puppet provisioner has only three fields:

• type (string) the provisioner type, in the case of the shell provisioner the value must be puppet-masterless.
• manifest_file (string) the absolute path of the Puppet manifest on the local filesystem.
• staging_directory (string) the location on the remote machine to where the manifest is uploaded. If empty, the manifest is uploaded in the user home.

Here is an example of a shell provisioner:

"provisioners": [{
    "type": "puppet-masterless",
    "manifest_file": "/Users/john/puppet/site.pp",
    "staging_directory" : "/tmp"
}]

Complete configuration example

{
    "builders": [{
        "type": "amazon-ebs",
        "access_key": "AMAZON_1234556790",
        "secret_key": "AMAZON_SECRET_12345",
        "region": "eu-west-1",
        "source_ami": "ami-9bf6e0ef",
        "instance_type": "t1.micro",
        "ssh_username": "ec2-user",
        "ami_name": "groovy",
        "keypair": "mykeypair",
        "keypair_location":"/Users/John/.ec2/mykeypair.pem",
        "security_group": "default-security"
    }],
    "provisioners": [{
        "type": "puppet-masterless",
        "manifest_file": "/Users/john/puppet/site.pp",
        "staging_directory" : "/tmp"
    }]
}