Render locally

This page is for a module author with a scaffolded guest project who wants to see what their Composition produces before publishing anything. It runs the runtime built from a checkout of this repository against a Path module on your machine. Installing the runtime in a cluster is out of scope.

You need the crossplane CLI, Docker (the render engine runs in it) and a Rust toolchain to build the runtime from the checkout.

Use two terminals. In the checkout, start the runtime with --module-dir set to your project directory (an absolute path is simplest):

cargo run --release -p function-wasm -- --insecure --debug --module-dir=<your project directory>

In your project directory, build the module and render with the Development runtime that the scaffold’s example/functions.yaml declares:

guestfn build
crossplane render example/xr.yaml example/composition.yaml example/functions.yaml

The example Composition uses module.type: Path with path: fn.wasm. For a cluster, use type: OCI with an oci reference, as the Input reference describes.

Rendering asserts nothing. To run this loop on the examples in this repository, see the development guide.