Modifying Builtin Plugins

Modifying Built-in Plugins

Built-in plugin sources are standalone Golem applications under plugins/. Their committed WASMs are embedded by BUILTIN_PLUGINS in golem-registry-service/src/services/builtin_plugin_provisioner.rs, making registry-service startup independent of filesystem paths and CLI launch mode.

Source and SDK Changes

Read the plugin's scoped AGENTS.md, manifests, and current source before editing. For the OTLP exporter, preserve the current async oplog processor API and imports:

use golem_rust::bindings::golem::api::oplog::{OplogEntry, OplogIndex};
use golem_rust::oplog_processor::exports::golem::api::oplog_processor::Guest as OplogProcessorGuest;
use golem_rust::schema::wit::wire::{AgentId, ComponentId};

Guest::process is async, metadata is golem_rust::oplog_processor::host::AgentMetadata, and the export macro uses with_types_in golem_rust::oplog_processor. Find dependency versions/features in current root, SDK, and plugin manifests with targeted rg; do not infer them from old examples or add compatibility aliases.

Build and Validate

Prefer the repository task:

cargo make build-plugins
wasm-tools validate --features all plugins/otlp-exporter.wasm

build-plugins uses cargo-make's CARGO_MAKE_CRATE_TARGET_DIRECTORY; do not replace it with target/... or cargo metadata. Every mutating golem build command must include --yes. Check that the copied WASM exists, is non-empty, validates, and changed when source/SDK inputs changed. Commit it: registry service uses include_bytes! at compile time.

Provisioning Changes

BuiltinPluginsConfig is only the tagged Enabled/Disabled switch. Plugin metadata and embedded bytes belong in BuiltinPluginDescriptor/BUILTIN_PLUGINS, not config, bootstrap, CLI, environment variables, or test-framework path plumbing.

When enabled, startup creates/finds the built-in owner's system app/environment, hash-updates descriptor components, deploys the environment once, then idempotently registers each descriptor. New environments transactionally receive grants for all plugins owned by the built-in-plugin owner; those grants cannot be deleted. Provisioning does not backfill by iterating existing environments.

Bump the descriptor version when publishing a distinct plugin version. If only provisioning changes, the WASM need not be rebuilt. Keep current behavior direct and remove superseded architecture rather than retaining backwards-compatible branches.

Verification

• Plugin-only Rust checks/tests from plugins/<plugin>/ as appropriate
• cargo make build-plugins and WASM validation after source, SDK, or manifest changes
• cargo check -p golem-registry-service after descriptor/provisioner changes
• cargo make integration-tests-group7 for authoritative built-in plugin tests

Tests that invoke Cargo, Golem, or a compiler as a subprocess belong specifically in the CLI integration test suite. Unit tests, worker-executor tests, and non-CLI integration tests must not spawn them.