Add component examples built from example core modules

Also, specify how to reproduce the wasi-component-adapter binaries.

.github/workflows/build.yml

@@ -63,6 +63,8 @@ jobs:
         key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
     - name: Install Wasm32-wasi target
       run: rustup target add wasm32-wasi
+    - name: Install wasm-tools
+      run: cargo install --locked [email protected]
     - name: Build Rust examples
       working-directory: ./examples
       run: make all

Cargo.toml

@@ -68,6 +68,7 @@ exclude = [
   "examples/rust-basic",
   "examples/rust-fetch",
   "examples/rust-kv",
+  "examples/rust-pdf-create",
   "examples/rust-params",
   "examples/rust-wasi-nn",
   "examples/rust-wasi-nn-preload",

examples/Makefile

@@ -1,38 +1,32 @@
-.PHONY: all rust-* pdf-create
+SUBDIRS = rust-basic rust-fetch rust-kv rust-wasi-nn rust-wasi-nn-preload rust-pdf-create
+COMPONENTS = $(addprefix components/, $(SUBDIRS))
+COMPONENT_TARGETS = components/rust-basic components/rust-kv components/rust-params
 
-rust-basic:
-	cd rust-basic && \
-	cargo build --target wasm32-wasi --release && \
-	cp target/wasm32-wasi/release/rust-basic.wasm ./basic.wasm
+all: $(SUBDIRS) rust-params $(COMPONENT_CURRENT_SUPPORTED_TARGETS) components/rust-params
 
-rust-fetch:
-	cd rust-fetch && \
-	cargo build --target wasm32-wasi --release && \
-	cp target/wasm32-wasi/release/rust-fetch.wasm ./index.wasm
+.PHONY: $(SUBDIRS) rust-params $(COMPONENT_CURRENT_SUPPORTED_TARGETS) components/rust-params
 
-rust-kv:
-	cd rust-kv && \
-	cargo build --target wasm32-wasi --release && \
-	mv target/wasm32-wasi/release/rust-kv.wasm ./kv.wasm
+$(SUBDIRS):
+	cd $@ && \
+		cargo build --target wasm32-wasi --release && \
+			cp target/wasm32-wasi/release/$@.wasm ./$@.wasm
 
 rust-params:
-	cd rust-params && \
-	cargo build --target wasm32-wasi --release && \
-	mv target/wasm32-wasi/release/rust-params.wasm "./[id].wasm"
-
-rust-wasi-nn:
-	cd rust-wasi-nn && \
-	cargo build --target wasm32-wasi --release && \
-	mv target/wasm32-wasi/release/rust-wasi-nn.wasm "./inference.wasm"
-
-rust-wasi-nn-preload:
-	cd rust-wasi-nn-preload && \
-	cargo build --target wasm32-wasi --release && \
-	mv target/wasm32-wasi/release/rust-wasi-nn-preload.wasm "./inference.wasm"
-
-rust-pdf-create:
-	cd rust-pdf-create && \
-	cargo build --target wasm32-wasi --release && \
-	mv target/wasm32-wasi/release/rust-pdf-create.wasm ./index.wasm
-
-all: rust-basic rust-fetch rust-kv rust-params rust-wasi-nn
+	cd $@ && \
+		cargo build --target wasm32-wasi --release && \
+			cp target/wasm32-wasi/release/$@.wasm "./[id].wasm"
+
+$(COMPONENTS):
+	mkdir -p $@
+	make $(@:components/%=%)
+	cp $(@:components/%=%)/*.toml $@/
+	wasm-tools component new $(@:components/%=%)/$(@:components/%=%).wasm \
+		--adapt wasi_snapshot_preview1=components/wasi-component-adapter/wasi_snapshot_preview1-command.wasm \
+		-o $@/$(@:components/%=%).wasm
+
+components/rust-params:
+	mkdir -p $@
+	make rust-params
+	wasm-tools component new rust-params/[id].wasm \
+		--adapt wasi_snapshot_preview1=components/wasi-component-adapter/wasi_snapshot_preview1-command.wasm \
+		-o $@/[id].wasm

examples/components/.gitignore

@@ -0,0 +1 @@
+/rust-*

examples/components/README.md

@@ -0,0 +1,6 @@
+# Component model examples
+
+This directory contains core module examples found in the parent
+directory, adapted with the
+[`wasi-component-adapter`](./wasi-component-adapter/README.md) so that they are
+converted to WebAssembly components.

examples/components/wasi-component-adapter/README.md

@@ -0,0 +1,58 @@
+# WASI component adapter
+
+The Bytecode Alliance provides a WASI component adapter that allows a
+WASI WebAssembly module to be compiled to a WebAssembly component.
+
+You can reproduce this WASI component adapter by running:
+
+```shell-session
+$ git clone [email protected]:bytecodealliance/wasmtime.git
+$ cd wasmtime
+$ cargo build -p wasi-preview1-component-adapter \
+    --target wasm32-unknown-unknown --release
+```
+
+You can find the WASI component adapter at
+`target/wasm32-unknown-unknown/release/wasi_snapshot_preview1.wasm`.
+
+This adapter is valid for a WASI reactor. If you want to build an
+adapter for a WASI command, you can run:
+
+```shell-session
+$ git clone [email protected]:bytecodealliance/wasmtime.git
+$ cd wasmtime
+$ cargo build -p wasi-preview1-component-adapter \
+    --features command \
+    --no-default-features \
+    --target wasm32-unknown-unknown --release
+```
+
+## Converting a WebAssembly module to a WebAssembly component
+
+In order to convert a WebAssemby module to a WebAssembly component,
+you can achieve this goal by using `wasm-tools`, along with the WASI
+component adapter you have just built.
+
+You can link to the reactor WASI adapter like so:
+
+```shell-session
+$ wasm-tools component new my-wasm-module.wasm \
+    --adapt wasi_snapshot_preview1=wasi_snapshot_preview1-reactor.wasm \
+    -o my-wasm-component.wasm
+```
+
+Or you can link to the command WASI adapter like the following:
+
+```shell-session
+$ wasm-tools component new my-wasm-module.wasm \
+    --adapt wasi_snapshot_preview1=wasi_snapshot_preview1-command.wasm \
+    -o my-wasm-component.wasm
+```
+
+In both cases, you can check that the component is valid, and output
+the WIT definition associated with it, like:
+
+```shell-session
+$ wasm-tools validate my-wasm-component.wasm --features component-model
+$ wasm-tools component wit component.wasm
+```