Autopilot SDK Structure

The source code for the Autopilot SDK is composed of 3 core directories:

• cli: contains source code for the ap CLI.
• codegen: contains the source code for generating code, Kubernetes manifests, and other project files necessary to build and deploy the operator. codegen is invoked by the ap generate command, but can be invoked manually (see debuggable_generate.go for an example).
• pkg: libraries used for running Autopilot Operators.

CLI Design

The ap CLI is designed to manage the full lifecycle of the Operator, from code generation, build, and deployment.

Autopilot Operators can be built and deployed via standard means (e.g. go build, docker, kubectl apply). The ap CLI is designed to simplify this process, without being a required component.

Codegen Design

The codegen package contains the root Run, Load and Generate functions which are used to generate code and other project files from the autopilot.yaml file.

It contains subpackages model, templates, and util.

• model - contains the internal model of project data parsed from the autopilot.yaml as well as utility functions which are used to render templates for generated files.

• templates - contains the templates used to render generated code, deployment, and project files. Templates are organized by type, with code containing all templates for generated .go files, and deploy containing templates for generated Kubernetes manifests.

For the full list of files generated by Autopilot, see generate.go#projectFiles and generate.go#phaseFiles.

Pkg Design

pkg contains the core libraries for running Autopilot Operators. It is broken up into the following subpackages:

• config: defaults and helper functions for loading the Autopilot Operator config. Read more about the Autopilot Operator config in the reference documentation.
• defaults: defaults core to the system. Default file location of autopilot.yaml as well as other variables (which can be overridden in init() functions).
• ezkube: ezkube contains a client which is a convenience wrapper for the dynamic client.Client of the controller-runtime library. It adds convenience functions for operators such as the Ensure function which applies resources to Kubernetes, setting owner references and retrying on resource conflicts.
• metrics: defines the base metrics.Client on which generated metrics code is based. The implemented metrics client is designed primarily for querying Prometheus.
• run: contains the main entrypoint for Autopilot Operators. The Operator’s generated main.go calls the run.Run function which runs the user’s scheduler Scheduler.
• scheduler: contains utilities and shared code for the generated scheduler.go, which is responsible for calling the user-defined workers.
• utils: utilities used in various places in generated code.
• version: small package containing the current version of Autopilot itself. This version is stored as a variable which is set at compile-time by Autopilot’s Makefile.