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

Managing stderr and stdout

Remember that Packer builds sources in parallel by forking a new process for each one and waiting for them to finish. This means the output for each build dumps its output into the same stdout stream at once. Unfortunately, as of this writing, there is no feature to specify one log file per process. Instead, each process output gets a random color by default. This is helpful for distinguishing build output with your eyes only if your display shows colored text. Also, note that redirecting output to a file or specifying an output file via the PACKER_LOG_FILE environment variable will technically preserve color highlighting, but not all text editors or tools show or preserve shell color escape sequences. In all honesty, Packer’s default output is not ideal for automation, and it may be important to break output up by the process. For this, the -machine-readable build flag is available. Specifying this flag prefixes every line in the shell output with...