Impact GO Work Heroku Buildpack

A Heroku buildpack that configures a GO project built on the new 1.18 workspace.

Detailed Description

This buildpack will setup Heroku GO build directives and the GO procfile based on environment variables. This environmental variable solution will allow a monorepo relying on a GO workspace to build multiple different dynos.

This buildpack will not compile GO code or complete a release. It is intended as a pre-processor for the standard GO work buildpack.

Environment Variables

2 environment variables are expected, both pointing to files within the GO project itself.

HEROKU_WORK_DIRECTIVES_FILE

This variable points to a file containing Heroku build directives that will be added to the go.work file.

For example:

HEROKU_WORK_DIRECTIVES_FILE=project/heroku-directives.txt

The project/heroku-directives.txt file contains the following content

// +heroku goVersion go1.18
// +heroku install ./cmd/...

The go.work file also has the placeholder //HEROKU_WORK_DIRECTIVES added.

The build will replace the placeholder variable //HEROKU_WORK_DIRECTIVES with the content of the project/heroku-directives.txt file.

HEROKU_WORK_PROCFILE

This variable points to a file containing the Heroku procfile contents.

For example:

HEROKU_WORK_PROCFILE=project/Project-Procfile

The project/Project-Procfile file contains the following content

web: server

The contents of this file are copied to the root of the project in a new file named Procfile.