Book Image

HashiCorp Packer in Production

By : John Boero
Book Image

HashiCorp Packer in Production

By: John Boero

Overview of this book

Creating machine images can be time-consuming and error-prone when done manually. HashiCorp Packer enables you to automate this process by defining the configuration in a simple, declarative syntax. This configuration is then used to create machine images for multiple environments and cloud providers. The book begins by showing you how to create your first manifest while helping you understand the available components. You’ll then configure the most common built-in builder options for Packer and use runtime provisioners to reconfigure a source image for desired tasks. You’ll also learn how to control logging for troubleshooting errors in complex builds and explore monitoring options for multiple logs at once. As you advance, you’ll build on your initial manifest for a local application that’ll easily migrate to another builder or cloud. The chapters also help you get to grips with basic container image options in different formats while scaling large builds in production. Finally, you’ll develop a life cycle and retention policy for images, automate packer builds, and protect your production environment from nefarious plugins. By the end of this book, you’ll be equipped to smoothen collaboration and reduce the risk of errors by creating machine images consistently and automatically based on your defined configuration.
Table of Contents (18 chapters)
1
Part 1: Packer’s Beginnings
7
Part 2: Managing Large Environments
11
Part 3: Advanced Customized Packer

Using the manifest post-processor

Collecting a lot of build data together can result in a mess of directories and artifacts without any way to index or organize them. Packer does provide a simple mechanism to index this data. The manifest post-processor can be used to generate a helpful JSON document listing what was generated during the build. The manifest isn’t enabled by default but can be enabled by simply adding a post-processor for the manifest in just one line:

post-processor "manifest" {}

If you simply enable the manifest post-processor, Packer will use default settings, which are pretty useful, without customizing anything. This means that a JSON document will be created or appended at the ./packer-manifest.json path. A list of all builds will be maintained within the manifest. It would be wise to either rotate this file or store it inside a JSON document database such as MongoDB if you wish to search for it later. Or, we can see in the next chapter...