Architecture

gödel consists of the godelw wrapper script, the project configuration files in godel/config and the godel Go executable.

Overview

At a high level, the godel executable is a task dispatcher: it determines the task that should be run based on the flags and arguments provided by the user and runs the task. The tasks that can be run are a combination of the built-in godel tasks (which are executed in-process) and plugin tasks, which are tasks that are supplied by plugins defined in the project configuration.

The godelw script ensures that the godel executable is available locally (and downloads it if it is not) and provides the wrapper script path as an argument to the invocation. The godel executable ensures that the plugin executables and assets defined in project configuration are available locally (and resolves them if they are not).

godelw

godelw is a bash script that is used as the entry point for gödel. The purpose of the script is to locate and invoke the godel executable and to provide it with the configuration specified in the current project. A typical invocation takes the form ./godelw [args]. The godelw wrapper script ensures that the godel executable of the proper version is available locally, downloading it if it does not exist. The script then invokes the godel executable with the --wrapper flag and provides the absolute path to the godelw script being invoked as the value of the flag. The script also passes along all of the user-specified arguments. This setup is used so that the godel executable itself does not need to be checked in as part of a project.

godel

godel is a Go executable. The godel executable runs the task specified by the flags/arguments provided by the user. If the --wrapper flag is provided, then the directory of the value is used as the project directory for the invocation and the configuration is read from the godel/config directory of the project. If the godel.yml configuration file specifies plugins and/or assets for the project, the godel executable ensures that they are available locally, resolving them if they are not. The tasks provided by the plugins are then added to the task list for the executable.

After this point, the godel executable determines the task that should be run based on the flags and arguments provided by the user and invokes the task. Tasks are either built-in tasks or plugin tasks. If a task is a built-in task, it is defined as part of the godel executable and run in-process. If the task is a plugin task, godel invokes the plugin executable with the appropriate arguments (as defined by the plugin API) and the plugin executable handles the rest of the execution.

Plugins

gödel provides a mechanism to define plugins for a project. Plugins are executables that provide tasks that can be run for gödel. Because Go does not have first-class cross-platform support for native plugins, plugins are fully independent executables (and can be written in any language). An executable becomes a gödel plugin by satisfying a particular API, which consists of returning known structured output in response to specific arguments and by supporting a specific set of flags and values defined by gödel's plugin API. When a plugin task is executed, the plugin executable is invoked as a separate process.

See Plugins for more information.