The SDK uses bazel for its build.
Create a directory with your WORKSPACE file, source files, and BUILD files:
WORKSPACE:
workspace(name = "my_extension")
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
# Replace '<CPP-SDK-SHA>' with actual SHA from github.
http_archive(
name = "proxy_wasm_cpp_sdk",
strip_prefix = "proxy-wasm-cpp-sdk-<CPP-SDK-SHA>",
url = "https://github.com/proxy-wasm/proxy-wasm-cpp-sdk/archive/<CPP-SDK-SHA>.tar.gz",
)
load("@proxy_wasm_cpp_sdk//bazel/dep:deps.bzl", "wasm_dependencies")
wasm_dependencies()
load("@proxy_wasm_cpp_sdk//bazel/dep:deps_extra.bzl", "wasm_dependencies_extra")
wasm_dependencies_extra()
Source file (myplugin.cc):
#include <string>
#include <unordered_map>
#include "proxy_wasm_intrinsics.h"
class ExampleContext : public Context {
public:
explicit ExampleContext(uint32_t id, RootContext* root) : Context(id, root) {}
FilterHeadersStatus onRequestHeaders(uint32_t headers, bool end_of_stream) override;
void onDone() override;
};
static RegisterContextFactory register_ExampleContext(CONTEXT_FACTORY(ExampleContext));
FilterHeadersStatus ExampleContext::onRequestHeaders(uint32_t headers, bool end_of_stream) {
logInfo(std::string("onRequestHeaders ") + std::to_string(id()));
auto path = getRequestHeader(":path");
logInfo(std::string("header path ") + std::string(path->view()));
return FilterHeadersStatus::Continue;
}
void ExampleContext::onDone() { logInfo("onDone " + std::to_string(id())); }
BUILD:
load("@proxy_wasm_cpp_sdk//bazel/wasm:wasm.bzl", "wasm_cc_binary")
wasm_cc_binary(
name = "myplugin.wasm",
srcs = [
"myplugin.cc",
],
deps = [
"@proxy_wasm_cpp_sdk//:proxy_wasm_intrinsics",
],
)
It is recommended to use Bazelisk installed as Bazel:
On Linux, run the following commands:
sudo wget -O /usr/local/bin/bazel https://github.com/bazelbuild/bazelisk/releases/latest/download/bazelisk-linux-amd64
sudo chmod +x /usr/local/bin/bazel
Several dependencies are needs in order to build a C++ WebAssembly plugins with Bazel.
on Unbuntu, run the following command:
sudo apt-get install gcc curl python3
Then run the following Bazel command:
bazel build //:myplugin.wasm
After the command finishes, you should be able to find myplugin.wasm file under ./bazel-bin folder.
A Dockerfile for the C++ SDK is provided in sdk.Dockerfile.
It can built in this directory by:
docker build -t wasmsdk -f sdk.Dockerfile .
The docker image can be used for compiling wasm files:
docker run \
-u $(id -u):$(id -g) \
-e HOME="/home" \
-e USER=${USER} \
--mount type=bind,source=${PWD},target=/work \
-w /work \
wasmsdk \
/bin/bash -lc \
'bazel build //:myplugin.wasm && cp bazel-bin/myplugin.wasm myplugin.wasm && bazel clean --expunge'After the command finishes, you should be able to find myplugin.wasm file along with source files.