48 lines
2.4 KiB
Markdown
48 lines
2.4 KiB
Markdown
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---
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layout: "docs"
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---
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# What is Packer?
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Packer is a tool for creating identical machine images for multiple platforms
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from a single source configuration. Packer is lightweight, runs on every major
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operating system, and is highly performant, creating machine images for
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multiple platforms in parallel.
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A _machine image_ is a single static unit that contains a pre-configured operating
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system and installed software which is used to quickly create new running machines.
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Machine image formats change for each platform. Some examples include
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[AMIs](http://en.wikipedia.org/wiki/Amazon_Machine_Image) for EC2,
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VMDK/VMX files for VMware, OVF exports for VirtualBox, etc.
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Historically, creating
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these images has been a predominantly manual process. Any existing automated tools were able to
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create only one type of image. Packer, on the other hand, is able to automatically
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create any type of image, all from a single source configuration.
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Pre-baked machine images have a lot of advantages, but we've been unable to
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benefit from them because they have been too tedious to create and manage.
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Packer tears down this barrier, allowing the benefits of pre-baked machine
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images to become available to everyone. Some benefits include:
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* Super fast infrastructure deployment. Packer images allow you to launch
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completely provisioned and configured machines in seconds, rather than
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several minutes or hours. This benefits not only production, but development as well,
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since development virtual machines can also be launched in seconds, without waiting
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for a typically much longer provisioning time.
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* Multi-provider portability. Because Packer creates identical images for
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multiple platforms, you can run production in AWS, staging/QA in a private
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cloud like OpenStack, and development in desktop virtualization solutions
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such as VMware or VirtualBox. Each environment is running an identical
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machine image, giving ultimate portability.
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* Improved stability. Packer installs and configures all the software for
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a machine at the time the image is built. If there are bugs in these scripts,
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they'll be caught early, rather than several minutes after a machine is launched.
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* Improved testability. After a machine image is built, that machine image
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can be quickly launched and smoke tested to verify that things appear to be
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working. If they are, you can be confident that any other machines launched
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from that image will function properly.
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