remove wasi-vfs dependency

It turns out that wasi-vfs isn't needed after all -- our Wizer initialization
step is sufficient to allow CPython to load everything it needs from the host
filesystem.  As a bonus, skipping the wasi-vfs step ensures that the module size
is automatically minimized -- no need to use `rsync` for staging and excluding
files by hand.

One possible drawback is that an application might try to dynamically load
modules from the filesystem at runtime (either built-in Python modules or
otherwise).  In that case, we may need to either use wasi-vfs or give the
developer some other way to pull the needed modules in at Wizer time (e.g. via
an app-provided init function which is called from the Wizer init function).

Signed-off-by: Joel Dice <[email protected]>

Author: dicej

.gitmodules

@@ -1,6 +1,3 @@
 [submodule "cpython"]
         path = cpython
         url = https://github.com/python/cpython
-[submodule "wasi-vfs"]
-        path = wasi-vfs
-        url = https://github.com/dicej/wasi-vfs

Cargo.toml

@@ -13,5 +13,4 @@ http = "0.2"
 spin-sdk = { git = "https://github.com/fermyon/spin" }
 wit-bindgen-rust = { git = "https://github.com/bytecodealliance/wit-bindgen", rev = "dde4694aaa6acf9370206527a798ac4ba6a8c5b8" }
 pyo3 = { version = "0.17.3", features = [ "abi3-py310" ] }
-wasi-vfs = { path = "./wasi-vfs" }
 once_cell = "1.16.0"

Makefile

@@ -1,24 +1,22 @@
 WASI_SDK_PATH ?= /opt/wasi-sdk
 
 .PHONY: build
-build: target/config.txt target/lib
+build: target/config.txt
 	PYO3_CONFIG_FILE=$$(pwd)/target/config.txt cargo build --release --target=wasm32-wasi
-	env -i wasi-vfs/target/release/wasi-vfs pack target/wasm32-wasi/release/python_wasi.wasm \
-		--mapdir lib::$$(pwd)/target/lib \
-		-o target/wasm32-wasi/release/python-wasi-vfs.wasm
-	env -i PYTHONUNBUFFERED=1 PYTHONPATH=/py:/site-packages \
-		$$(which wizer) target/wasm32-wasi/release/python-wasi-vfs.wasm \
-		--inherit-env true --wasm-bulk-memory true --allow-wasi --dir py \
+	env -i PYTHONUNBUFFERED=1 \
+		PYTHONHOME=/python \
+		PYTHONPATH=/python:/py:/site-packages \
+		$$(which wizer) \
+		target/wasm32-wasi/release/python_wasi.wasm \
+		--inherit-env true \
+		--wasm-bulk-memory true \
+		--allow-wasi \
+		--dir py \
+		--mapdir python::$$(pwd)/cpython/builddir/wasi/install/lib/python3.11 \
 		--mapdir site-packages::$$(cd py && find $$(pipenv --venv)/lib -name site-packages | head -1) \
-		-o target/wasm32-wasi/release/python-wasi-vfs-wizer.wasm
+		-o target/wasm32-wasi/release/python-wasi-wizer.wasm
 
 target/config.txt:
 	mkdir -p target
 	cp config.txt target
 	echo "lib_dir=$$(pwd)/cpython/builddir/wasi" >> $@
-
-target/lib:
-	mkdir -p $@
-	rsync -a --exclude='*.a' --exclude='*.pyc' --exclude='*.whl' --exclude=Makefile \
-		--exclude=Changelog --exclude=NEWS.txt \
-		cpython/builddir/wasi/install/lib/python3.11 $@

README.md

@@ -1,15 +1,13 @@
 # spin-python-sdk
 
-This is an experiment to build a Spin Python SDK using CPython, wasi-vfs, and PyO3.
+This is an experiment to build a Spin Python SDK using CPython, Wizer, and PyO3.
 
 ## Prerequisites
 
 - [CPython](https://github.com/python/cpython) build prereqs (e.g. Make, Clang, etc.)
 - [Rust](https://rustup.rs/) (including `wasm32-wasi` target)
-- [wasi-sdk](https://github.com/WebAssembly/wasi-sdk) v16 or later
 - [Wizer](https://github.com/bytecodealliance/wizer) v1.6.0 or later
 - [Spin](https://github.com/fermyon/spin)
-- [rsync](https://rsync.samba.org/) -- used at build time for copying files around; we could replace this with something more portable, if desired
 - [pipenv](https://pypi.org/project/pipenv/) for installing Python project dependencies
 
 ## Building and Running
@@ -32,13 +30,7 @@ make install
 cd ../../..
 ```
 
-Then, build the wasi-vfs CLI:
-
-```
-(cd wasi-vfs && cargo build --release -p wasi-vfs-cli)
-```
-
-Finally, build and run this app:
+Then, build and run this app:
 
 ```
 (cd py && pipenv install)

py/app.py

@@ -19,7 +19,7 @@ def handle_request(request):
     print(f"And here's some TOML: {toml.loads(some_toml)}")
 
     my_file = open("/foo.txt", "r")
-    print(f"And here's the contents of foo.txt: {my_file.read()}")
+    print(f"And here's the content of foo.txt: {my_file.read()}")
 
     response = http_send(Request("GET", "https://some-random-api.ml/facts/dog", [], None))
     print(f"Got dog fact: {str(response.body, 'utf-8')}")

spin.toml

@@ -10,7 +10,7 @@ id = "spin-webrtc"
 environment = { hello = "teapot" }
 config = { redis_address = "redis://127.0.0.1:6379" }
 files = [{ source = "static-assets/", destination = "/" }]
-source = "target/wasm32-wasi/release/python-wasi-vfs-wizer.wasm"
+source = "target/wasm32-wasi/release/python-wasi-wizer.wasm"
 allowed_http_hosts = ["insecure:allow-all"]
 [component.trigger]
 route = "/..."

src/lib.rs

@@ -224,7 +224,6 @@ fn spin_redis_module(_py: Python<'_>, module: &PyModule) -> PyResult<()> {
     module.add_function(pyo3::wrap_pyfunction!(redis_set, module)?)?;
     module.add_function(pyo3::wrap_pyfunction!(redis_smembers, module)?)?;
     module.add_function(pyo3::wrap_pyfunction!(redis_srem, module)?)
-    
 }
 
 #[pyo3::pyfunction]
@@ -275,8 +274,6 @@ fn do_init() -> Result<()> {
 
 #[export_name = "wizer.initialize"]
 pub extern "C" fn init() {
-    std::hint::black_box(wasi_vfs::__internal_wasi_vfs_rt_init);
-
     do_init().unwrap();
 }