This folder contains some of the configuration of the buildbots managed at Google. The workers are deployed on Google Cloud.
To deploy build bots workers, we need to create a bunch of virtual machines on Google Cloud. There are multiple ways to do this. Terraform is convenient as it offers to declare the required machines in config files and then create/update the machines in the cloud.
This way we have version control over the infrastructure and we can review changes before applying them. In case something goes wrong, we can easily revert changes. It also allows us to copy & paste parts of the infrastructure for additional machines.
Internally, Terraform is using Kubernetes to manage the deployment of software to machines. The software installed on the build machines is defined in Docker images. An image is a (layered) file system with all the tools and settings required for the worker.
The images are stored in a “registry” (gcr.io in this case) and are then pulled from the machines where they are executed. The images can be versioned so that we can pick exactly which version of the image we want to run.
The contents of a Docker image is again defined in a config file called Dockerfile. A Dockerfile is a sort of script defining on how to install and configure the software for a machine. We keep those files in this repository as well so we can review changes and revert changes if something breaks.
The docker images also allow contributors to reproduce a failing test locally, as they will get the same machine configuration as used on the server.
docker - Dockerfiles for the workers and some scriptingterraform - cluster configuration and deploymentconfig.sh - variables used in other scriptsgcloud_config.sh - configure cloud tooling