wasmtime: update to v0.32.0

[kfaseela]

attempting to update wasmtime in Envoy main

Signed-off-by: Faseela K [email protected]

[kfaseela]

cc @phlax

[kfaseela]

@PiotrSikora : Any idea how to fix the current build error?

ERROR: /home/runner/.cache/bazel/_bazel_runner/ae21fb6b2e26a9267f16b46bb90ea321/external/proxy_wasm_cpp_host__cpufeatures__0_2_1/BUILD.bazel:33:13: Label '@proxy_wasm_cpp_host__libc__0_2_112//:libc' is duplicated in the 'deps' attribute of rule 'cpufeatures'

how do i fix this duplicate?
https://github.com/proxy-wasm/proxy-wasm-cpp-host/pull/205/files#diff-1f31b98481a005cda423a6abf0bf64bcbe3bac116b937a92451df216b02e1f7aR67

[PiotrSikora]

@kfaseela thanks for working on this! Unfortunately, you need to fix bazel/cargo/remote/BUILD.errno-0.2.8.bazel file manually (just undo the selects change), see comments in #196.

[PiotrSikora]

@kfaseela oops, it looks that you need to manually collapse them in bazel/cargo/remote/BUILD.cpufeatures-0.2.1.bazel as well, and exclude that file from format check in .github/workflows/cargo.yml.

[PiotrSikora]

This is a bit more complex than a simple update, but we're getting close. You need to:

1. Add this to bazel/cargo/Cargo.toml:

[package.metadata.raze.crates.rustix.'*'.buildrs_additional_environment_variables]
CARGO_CFG_RUSTIX_USE_LIBC="1"

2. Regenerate everything using cargo raze --generate-lockfile (it looks that some crates are outdated in current PR).
3. Update bazel/cargo/remote/BUILD.rustix-0.26.2.bazel so that the first select is merged into the second one, so that all targets depend on libc and errno, and not on linux_raw_sys.
4. Exclude bazel/cargo/remote/BUILD.rustix-0.26.2.bazel from format check.

[kfaseela]

This is a bit more complex than a simple update, but we're getting close. You need to:

1. Add this to bazel/cargo/Cargo.toml:

[package.metadata.raze.crates.rustix.'*'.buildrs_additional_environment_variables]
CARGO_CFG_RUSTIX_USE_LIBC="1"

2. Regenerate everything using cargo raze --generate-lockfile (it looks that some crates are outdated in current PR).
3. Update bazel/cargo/remote/BUILD.rustix-0.26.2.bazel so that the first select is merged into the second one, so that all targets depend on libc and errno, and not on linux_raw_sys.
4. Exclude bazel/cargo/remote/BUILD.rustix-0.26.2.bazel from format check.

Done. And thanks a lot for all the detailed feedback!

[PiotrSikora]

@kfaseela thanks for all the work, this looks good now! Would you mind updating proxy-wasm-cpp-host in your Envoy PR to your latest commit to verify that it works end-to-end before I merge this? Thanks!

[kfaseela]

@PiotrSikora It still failed : envoyproxy/envoy#19285

ERROR: /build/tmp/_bazel_envoybuild/400406edc57d332f0b9b805d2b8e33a1/external/envoy/test/extensions/common/wasm/BUILD:18:14: Linking external/envoy/test/extensions/common/wasm/wasm_vm_test failed: (Exit 1): clang failed: error executing command
(cd /build/tmp/_bazel_envoybuild/400406edc57d332f0b9b805d2b8e33a1/execroot/envoy_filter_example &&
exec env -
BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1
BAZEL_LINKLIBS=-l%:libstdc++.a
BAZEL_LINKOPTS=-lm
CC=clang
CXX=clang++
PATH=/usr/sbin:/usr/bin:/sbin:/bin:/opt/llvm/bin
PWD=/proc/self/cwd
/opt/llvm/bin/clang @bazel-out/k8-dbg/bin/external/envoy/test/extensions/common/wasm/wasm_vm_test-2.params)
Execution platform: @envoy_build_tools//toolchains:rbe_linux_clang_platform
ld.lld: error: undefined symbol: renameat2

referenced by syscalls.rs:189 (external/proxy_wasm_cpp_host__rustix__0_26_2/src/imp/libc/fs/syscalls.rs:189)
rustix-2123923521.rustix.d78db92e-cgu.5.rcgu.o:(rustix::imp::libc::fs::syscalls::renameat2::h9a4de3c870cc34f4) in archive bazel-out/k8-dbg/bin/external/com_github_wasmtime/librust_c_api-220117231.a
did you mean: renameat
defined in: /lib/x86_64-linux-gnu/libc.so.6
clang-12: error: linker command failed with exit code 1 (use -v to see invocation)

[PiotrSikora]

The build rules are fine, and I was able to sucessfully build envoyproxy/envoy#19285 locally. The issue is with the build image used in Envoy's CI (Ubuntu 18.04 with glibc 2.27), because rustix requires glibc 2.28 or newer for renameat2 when using libc backend. Interestingly, while the version of rustix (previously rsix) in wasmtime v0.32.0 defaults to linux-raw, it previously defaulted to libc, so this shouldn't be a new dependency, and it would be good to investigate why this became an issue.

Separately, the successfully built binary and tests crash in Envoy when initializing WasmVM, so there is a lot more work that needs to be done before this can be merged. I looked a bit into it, but I don't have any idea why it's broken.

If you want to investigate this, then I'd start with:

1. Figuring out the difference between tests here and in Envoy (i.e. why tests in this repository pass, but those in Envoy crash). It could be because of multiple WasmVM instances and canarying in Envoy that's missing in tests here, or simply because we don't have a good test coverage in this repository.
2. Figuring out why glibc became an issue (bisecting / looking at changes in rustix between v0.23.2 and v0.26.2, and in wasmtime between v0.31.0 and v0.32.0).

[PiotrSikora]

Separately, the successfully built binary and tests crash in Envoy when initializing WasmVM, so there is a lot more work that needs to be done before this can be merged. I looked a bit into it, but I don't have any idea why it's broken.

OK, I found the issue.

It looks that the ownership model for vectors was changed in wasmtime v0.32.0 (bytecodealliance/wasmtime@ce67e7f), so you need to remove those 3 lines from src/wasmtime/wasmtime.cc:

proxy-wasm-cpp-host/src/wasmtime/wasmtime.cc

Lines 433 to 435 in f383473

	for (auto i = ps.begin(); i < ps.end(); i++) { // TODO(mathetake): better way to handle?
	wasm_valtype_delete(*i);
	}

Once those lines are removed, all tests in Envoy pass, but we still need to figure out the glibc issue before this can be used in Envoy on Ubuntu 18.04.

[PiotrSikora]

5. Add this:

        "--cfg=feature=\"cc\"",

to rustc_flags in rustix_build_script target in bazel/cargo/remote/BUILD.rustix-0.26.2.bazel. This is temporary hack, until the bug is fixed in cargo-raze (see: google/cargo-raze#461).

@kfaseela you've missed this step (you'll also need to restore the exclusion for rustix in the format check - basically, revert .github/workflows/cargo.yml to the version from yesterday).

Other than that, everything looks fine now, so you could update Envoy PR once you incorporate those changes. Thanks!

[PiotrSikora]

LGTM, thanks!

Could you update envoyproxy/envoy#19285 to verify this end-to-end on Envoy's CI before merging?

[PiotrSikora]

• Figuring out the difference between tests here and in Envoy (i.e. why tests in this repository pass, but those in Envoy crash). It could be because of multiple WasmVM instances and canarying in Envoy that's missing in tests here, or simply because we don't have a good test coverage in this repository.

OK, I finally figured this out. This PR didn't update wasmtime to v0.32.0 in bazel/repositories.bzl, so the Wasmtime C API was still using v0.31.0 (without the aforementioned ownership changes from bytecodealliance/wasmtime@ce67e7f), whereas the Envoy PR updated sources, so it was building and failing tests against updated Wasmtime C API v0.32.0.

Verified and fixed in #209.

[kfaseela]

@PiotrSikora : Thank you so much for all the help with this PR!