How Packer Builds Run in Atlas

This briefly covers the internal process of running builds in Atlas. It's not necessary to know this information, but may be valuable to help understand implications of running in Atlas or debug failing builds.

Steps of Execution

  1. A Packer template and directory of files is uploaded via Packer Push or GitHub
  2. Atlas creates a version of the build configuration and waits for the upload to complete. At this point, the version will be visible in the UI even if the upload has not completed
  3. Once the upload finishes, Atlas queues the build. This is potentially split across multiple machines for faster processing
  4. In the build environment, the package including the files and Packer template are downloaded
  5. packer build is run against the template in the build environment
  6. Logs are streamed into the UI and stored
  7. Any artifacts as part of the build are then uploaded via the public Atlas artifact API, as they would be if Packer was executed locally
  8. The build completes, the environment is teared down and status updated within Atlas