Get Python apps working again after Viceroy WIT updates etc.

.github/workflows/python-ci.yml

@@ -10,13 +10,24 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: forge-amd64-medium
     steps:
     - uses: actions/checkout@v4
-    - name: Set Up Rust Toolchain
+    - name: Get wasiless submodule
+      # Org-internal submodules are very tricky to check out.
+      env:
+        SSHK: ${{ secrets.WASILESS_REPO_READ_KEY }}
+      run: |
+        mkdir -p $HOME/.ssh
+        echo "$SSHK" > $HOME/.ssh/ssh.key
+        chmod 600 $HOME/.ssh/ssh.key
+        export GIT_SSH_COMMAND="ssh -i $HOME/.ssh/ssh.key"
+        git submodule update --init --recursive
+    - name: Set up Rust toolchain
       uses: actions-rust-lang/setup-rust-toolchain@v1
       with:
         toolchain: '1.86.0'
+        target: wasm32-unknown-unknown
     - name: Set up Python
       uses: actions/setup-python@v5
       with:
@@ -25,8 +36,20 @@ jobs:
       run: pip install uv
     - name: Install dependencies
       run: uv sync
+    - name: Cache viceroy, wasm-tools, etc.
+      id: cache-cargo
+      uses: actions/cache@v4
+      with:
+        key: python-sdk-compatible-1
+        path: |
+            ~/.cargo/bin/
+    - name: Install wasm-tools and wac
+      if: steps.cache-cargo.outputs.cache-hit != 'true'
+      run: cargo install wasm-tools wac-cli
     - name: Install viceroy
-      run: cargo install --git https://github.com/fastly/Viceroy.git --branch sunfishcode/sync-wit viceroy
+      if: steps.cache-cargo.outputs.cache-hit != 'true'
+      # When you switch tags, update the cache key in the cache-cargo step.
+      run: cargo install --git https://github.com/fastly/Viceroy.git --tag erik/python-sdk-compatible-1 viceroy
     - name: Install dependencies
       run: uv sync --extra dev --extra test
     - name: Check formatting

.gitignore

@@ -8,4 +8,3 @@ __pycache__
 
 # Build artifacts
 /build/
-*.wasm

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "vendor/wasiless"]
+	path = vendor/wasiless
+	url = git@github.com:fastly/wasiless.git

Makefile

@@ -1,5 +1,8 @@
 # Fastly Compute Python SDK
 
+# Default Viceroy location. Set VICEROY env var to change.
+VICEROY ?= viceroy
+
 # Configuration
 STUBS_DIR := stubs
 BUILD_DIR := build
@@ -10,20 +13,35 @@ EXAMPLES := wit-bottle flask-app
 
 # Default example for serve target
 EXAMPLE ?= wit-bottle
-WASM_FILE := $(BUILD_DIR)/$(EXAMPLE).wasm
+WASM_FILE := $(BUILD_DIR)/$(EXAMPLE).composed.wasm
+
+TARGET_WORLD := fastly:compute/service
 
 # Generate WASM file paths for all examples
 EXAMPLE_WASMS := $(foreach example,$(EXAMPLES),$(BUILD_DIR)/$(example).wasm)
 
+# Composed wasm for each example
+COMPOSED_WASMS := $(foreach example,$(EXAMPLES),$(BUILD_DIR)/$(example).composed.wasm)
+
+WASILESS_ROOT := vendor/wasiless
+WASILESS_WASM := $(WASILESS_ROOT)/wasiless.wasm
+
 # Default target builds all examples
-all: $(EXAMPLE_WASMS)
+all: $(COMPOSED_WASMS)
+
+$(BUILD_DIR)/%.composed.wasm: $(BUILD_DIR)/%.wasm $(WASILESS_WASM)
+	@echo "Composing $* example"
+	wac compose --dep fastly:wasiless=$(WASILESS_WASM) --dep app:component=$< -o $@ wrap_app_in_wasiless.wac
 
 # Pattern rule for building any example
-$(BUILD_DIR)/%.wasm: $(EXAMPLES_DIR)/%.py wit/viceroy.wit wit/deps/fastly/compute.wit | $(BUILD_DIR)
+$(BUILD_DIR)/%.wasm: $(EXAMPLES_DIR)/%.py wit/viceroy.wit wit/deps/fastly/compute.wit fastly_compute/wsgi.py | $(BUILD_DIR)
 	@echo "Building $* example..."
 	rm -rf $(STUBS_DIR)
-	uv run componentize-py -d wit -w viceroy bindings $(STUBS_DIR)
-	uv run componentize-py -d wit -w viceroy componentize $* -p $(EXAMPLES_DIR) -p . -o $@
+	uv run componentize-py -d wit -w $(TARGET_WORLD) bindings $(STUBS_DIR)
+	uv run componentize-py -d wit -w $(TARGET_WORLD) componentize $* -p $(EXAMPLES_DIR) -p . -o $@
+
+$(WASILESS_WASM):
+	 $(MAKE) -C $(WASILESS_ROOT) wasiless.wasm
 
 # Create build directory
 $(BUILD_DIR):
@@ -32,10 +50,10 @@ $(BUILD_DIR):
 # Serve the specified example (default: wit-bottle)
 serve: $(WASM_FILE)
 	@echo "Serving $(EXAMPLE) example on http://127.0.0.1:7676"
-	viceroy serve $(WASM_FILE)
+	$(VICEROY) serve $(WASM_FILE)
 
 # Test all examples (requires all WASM files to be built)
-test: $(EXAMPLE_WASMS)
+test: $(COMPOSED_WASMS)
 	uv run --extra test pytest
 
 # List available examples
@@ -87,5 +105,4 @@ help:
 	@echo ""
 	@echo "Available examples: $(EXAMPLES)"
 
-.PHONY: all serve test list-examples build-all clean lint lint-fix format format-check help
-
+.PHONY: all serve test list-examples build-all clean lint lint-fix format format-check help $(WASILESS_WASM)

fastly_compute/testing.py

@@ -50,7 +50,7 @@ def test_my_endpoint(self):
     """
 
     REQUEST_TIMEOUT = 10
-    WASM_FILE = "build/wit-bottle.wasm"  # Default to the main example
+    WASM_FILE = "build/wit-bottle.composed.wasm"  # Default to the main example
     server: ViceroyServer = None  # Will be set by the fixture
 
     @staticmethod

fastly_compute/wsgi.py

@@ -40,7 +40,7 @@ def serve_wsgi_request(
 
     def write(body_data: bytes) -> None:
         """Write response body data (deprecated WSGI mechanism)."""
-        http_body.write(response_body, body_data, http_body.WriteEnd.BACK)
+        http_body.write(response_body, body_data)
 
     def start_response(
         status: str, headers: list[tuple[str, str]], exc_info: Any | None = None

tests/test_flask_example.py

@@ -1,14 +1,12 @@
 """Tests for the Flask example application."""
 
-import pytest
-
 from fastly_compute.testing import ViceroyTestBase
 
 
 class TestFlaskApp(ViceroyTestBase):
     """Integration tests for the Flask example application."""
 
-    WASM_FILE = "build/flask-app.wasm"
+    WASM_FILE = "build/flask-app.composed.wasm"
 
     def test_hello_endpoint(self):
         """Test the hello endpoint returns expected content."""