README

README.md

@@ -7,6 +7,69 @@ machine images to launch into any environment, such as VirtualBox, VMware,
 Amazon EC2, etc. Because this build process is automated, you can develop in
 VirtualBox, then deploy to EC2 with an identical image.
 
+## Quick Start
+
+First, get Packer by either downloading a pre-built Packer binary for
+your operating system or [downloading and compiling Packer yourself](#developing-packer).
+
+After Packer is installed, build your first machine image.
+
+```
+$ packer build quick-start.toml
+...
+```
+
+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](https://console.aws.amazon.com/). Packer
+builds your images, it does not manage their lifecycle. Where they go, how
+they're run, etc. is up to you.
+
+## Templates
+
+Templates are static configurations that describe what machine images
+you want to create, how to create them, and what format you finally want
+them to be in.
+
+Packer reads a template and builds all the requested machine images
+in parallel.
+
+Templates are written in [TOML](https://github.com/mojombo/toml). TOML is
+a fantastic configuration language that you can learn in minutes, and is
+very human-readable as well.
+
+First, a complete template is shown below. Then, the details and
+structure of a template are discussed:
+
+```toml
+name = "my-custom-image"
+
+[builder.amazon-ebs]
+source = "ami-de0d9eb7"
+
+[provision]
+
+  [provison.shell]
+  type = "shell"
+  path = "script.sh"
+
+[output]
+
+  [output.vagrant]
+```
+
+Templates are comprised of three parts:
+
+* **builders** (1 or more) specify how the initial running system is
+  built.
+
+* **provisioners** (0 or more) specify how to install and configure
+  software from within the base running system.
+
+* **outputs** (0 or more) specify what to do with the completed system.
+  For example, these can output [Vagrant](http://www.vagrantup.com)-compatible
+  boxes, gzipped files, etc.
+
 ## Developing Packer
 
 If you wish to work on Packer itself, you'll first need [Go](http://golang.org)

packer.go

@@ -1,8 +1,31 @@
 // This is the main package for the `packer` application.
 package main
 
-import (
+// A command is a runnable sub-command of the `packer` application.
-)
+// When `packer` is called with the proper subcommand, this will be
+// called.
+//
+// The mapping of command names to command interfaces is in the
+// Environment struct.
+type Command interface {
+	Run(args []string)
+}
+
+// The environment struct contains all the state necessary for a single
+// instance of Packer.
+//
+// It is *not* a singleton, but generally a single environment is created
+// when Packer starts running to represent that Packer run. Technically,
+// if you're building a custom Packer binary, you could instantiate multiple
+// environments and run them in parallel.
+type Environment struct {
+	commands map[string]Command
+}
 
 func main() {
+	env := Environment {
+		commands: map[string]Command {
+			""
+		},
+	}
 }