experimental

Documentation

Overview

Package experimental provides experimental APIs for intercepting func-e's Run lifecycle.

Experimental

This package is experimental and may change or be removed in future versions.

Usage Constraints

This package should ONLY be used by CLI entry points (main.go level).

DO NOT use this package in library code because:

1. Experimental packages in dependencies cause rev lock
2. CLI entry points would overwrite library hooks.

Example Usage

This is intended for CLI entry points that need to intercept enforce runtime aspects such as the home directory or Envoy version without requiring library dependencies to expose api.RunOption directly.

func main() {
    ctx := context.Background()

    // Define a middleware that re-uses the CLI home dir for Envoy runs.
    homeDirMiddleware := func(next api.RunFunc) api.RunFunc {
        return func(ctx context.Context, args []string, options ...api.RunOption) error {
            options = append(options, api.HomeDir(cliHome))
            return next(ctx, args, options...)
        }
    }

    // Set the middleware in context, so that it will be used downstream.
    ctx = middleware.WithRunMiddleware(ctx, homeDirMiddleware)

    // Use that context when calling a library function that uses func-e.
    if err := library.Main(ctx, os.Args[1:]); err != nil {
        log.Fatal(err)
    }
}