http_wasm_example.cc

// Copyright 2016-2020 Envoy Project Authors
// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <string>
#include <string_view>

#include "proxy_wasm_intrinsics.h"

class ExampleRootContext : public RootContext {
public:
  explicit ExampleRootContext(uint32_t id, std::string_view root_id) : RootContext(id, root_id) {}

  bool onStart(size_t) override;
  bool onConfigure(size_t) override;
  void onTick() override;
};

class ExampleContext : public Context {
public:
  explicit ExampleContext(uint32_t id, RootContext *root) : Context(id, root) {}

  void onCreate() override;
  FilterHeadersStatus onRequestHeaders(uint32_t headers, bool end_of_stream) override;
  FilterDataStatus onRequestBody(size_t body_buffer_length, bool end_of_stream) override;
  FilterHeadersStatus onResponseHeaders(uint32_t headers, bool end_of_stream) override;
  FilterDataStatus onResponseBody(size_t body_buffer_length, bool end_of_stream) override;
  void onDone() override;
  void onLog() override;
  void onDelete() override;
};
static RegisterContextFactory register_ExampleContext(CONTEXT_FACTORY(ExampleContext),
                                                      ROOT_FACTORY(ExampleRootContext));

bool ExampleRootContext::onStart(size_t) {
  LOG_TRACE("onStart");
  return true;
}

bool ExampleRootContext::onConfigure(size_t) {
  LOG_TRACE("onConfigure");
  proxy_set_tick_period_milliseconds(1000); // 1 sec
  return true;
}

void ExampleRootContext::onTick() { LOG_TRACE("onTick"); }

void ExampleContext::onCreate() { LOG_WARN(std::string("onCreate " + std::to_string(id()))); }

FilterHeadersStatus ExampleContext::onRequestHeaders(uint32_t, bool) {
  LOG_DEBUG(std::string("onRequestHeaders ") + std::to_string(id()));
  auto result = getRequestHeaderPairs();
  auto pairs = result->pairs();
  LOG_INFO(std::string("headers: ") + std::to_string(pairs.size()));
  for (auto &p : pairs) {
    LOG_INFO(std::string(p.first) + std::string(" -> ") + std::string(p.second));
  }
  return FilterHeadersStatus::Continue;
}

FilterHeadersStatus ExampleContext::onResponseHeaders(uint32_t, bool) {
  LOG_DEBUG(std::string("onResponseHeaders ") + std::to_string(id()));
  auto result = getResponseHeaderPairs();
  auto pairs = result->pairs();
  LOG_INFO(std::string("headers: ") + std::to_string(pairs.size()));
  for (auto &p : pairs) {
    LOG_INFO(std::string(p.first) + std::string(" -> ") + std::string(p.second));
  }
  addResponseHeader("X-Wasm-custom", "FOO");
  replaceResponseHeader("content-type", "text/plain; charset=utf-8");
  removeResponseHeader("content-length");
  return FilterHeadersStatus::Continue;
}

FilterDataStatus ExampleContext::onRequestBody(size_t body_buffer_length,
                                               bool /* end_of_stream */) {
  auto body = getBufferBytes(WasmBufferType::HttpRequestBody, 0, body_buffer_length);
  LOG_ERROR(std::string("onRequestBody ") + std::string(body->view()));
  return FilterDataStatus::Continue;
}

FilterDataStatus ExampleContext::onResponseBody(size_t /* body_buffer_length */,
                                                bool /* end_of_stream */) {
  setBuffer(WasmBufferType::HttpResponseBody, 0, 12, "Hello, world");
  return FilterDataStatus::Continue;
}

void ExampleContext::onDone() { LOG_WARN(std::string("onDone " + std::to_string(id()))); }

void ExampleContext::onLog() { LOG_WARN(std::string("onLog " + std::to_string(id()))); }

void ExampleContext::onDelete() { LOG_WARN(std::string("onDelete " + std::to_string(id()))); }