Publishing a Buf check plugin to the BSR

Publishing a plugin to the BSR allows you to share it with other developers. To publish a plugin, it must be compiled as a WASM binary.

The process varies depending on the language you're using — in this example, we'll use the rpc-suffix plugin built in Go from the quickstart.

Compiling the plugin

To compile your plugin to Wasm, you need to target the WebAssembly System Interface (WASI) syscall API. WASI provides a standard interface for Wasm modules to interact with the host system. The supported version is WASI 0.1.

For Go plugins, you can compile your plugin by setting the GOOS and GOARCH environment variables to wasip1 and wasm, respectively. This tells the Go compiler to target the WASI syscall API and compile the code to Wasm. For example, this command compiles the rpc-suffix plugin outputting a rpc-suffix.wasm file:

GOOS=wasip1 GOARCH=wasm go build -o rpc-suffix.wasm ./cmd/rpc-suffix

The output of this command is a Wasm binary file named rpc-suffix.wasm. The .wasm suffix is an important convention, as it tells the Buf CLI the plugin type. If the plugin doesn't have the .wasm suffix, the Buf CLI interprets it as a native plugin.

Pushing a plugin

To push a plugin to the BSR, you use the buf plugin push command. We'll use the rpc-suffix.wasm plugin built in Go from the quickstart and compiled to WASM to demonstrate how to push a plugin to the BSR.

buf plugin push buf.build/acme/rpc-suffix \
  --binary=rpc-suffix.wasm \
  --create \
  --create-type=check \
  --create-visibility=public

This command pushes the plugin rpc-suffix.wasm to the BSR organization acme at buf.build/acme/rpc-suffix.

Once pushed, the plugin is now available in the BSR and can be used by other developers.

Using the plugin

To use the plugin, you update your buf.yaml file to point to the remote plugin.

 version: v2
 modules:
   - path: proto
     name: buf.build/tutorials/lint-plugin
 lint:
   use:
     - STANDARD
    - RPC_SUFFIX
plugins:
  - plugin: buf.build/acme/rpc-suffix

Next, you need to update the buf.lock file to set the plugin version:

buf plugin update

When you run buf lint and buf breaking checks, they now use the plugin you just pushed to the BSR.

buf lint

proto/pet/v1/pet.proto:30:3:method name should not end with "Method" (buf.build/acme/rpc-suffix)