Add Promise support for http callout

README.md

@@ -21,6 +21,7 @@
 - [HTTP Headers](./examples/http_headers/)
 - [HTTP Response body](./examples/http_body/)
 - [HTTP Configuration](./examples/http_config/)
+- [HTTP Parallel Call](./examples/http_parallel_call/)
 - [gRPC Auth (random)](./examples/grpc_auth_random/)
 
 ## Articles & blog posts from the community

examples/http_parallel_call/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+publish = false
+name = "proxy-wasm-example-http-parallel-call"
+version = "0.0.1"
+authors = ["Zhuozhi Ji <[email protected]>"]
+description = "Proxy-Wasm plugin example: HTTP parallel call"
+license = "Apache-2.0"
+edition = "2018"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+log = "0.4"
+proxy-wasm = { path = "../../" }
+
+[profile.release]
+lto = true
+opt-level = 3
+codegen-units = 1
+panic = "abort"
+strip = "debuginfo"

examples/http_parallel_call/README.md

@@ -0,0 +1,27 @@
+## Proxy-Wasm plugin example: HTTP parallel call
+
+Proxy-Wasm plugin that makes multiply HTTP callout and combine responses as final response .
+
+### Building
+
+```sh
+$ cargo build --target wasm32-wasi --release
+```
+
+### Using in Envoy
+
+This example can be run with [`docker compose`](https://docs.docker.com/compose/install/)
+and has a matching Envoy configuration.
+
+```sh
+$ docker compose up
+```
+
+#### Access granted.
+
+Send HTTP request to `localhost:10000/headers`:
+
+```sh
+$ curl localhost:10000/headers
+Hello, World!\n
+```

examples/http_parallel_call/docker-compose.yaml

@@ -0,0 +1,36 @@
+# Copyright 2022 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.
+
+services:
+  envoy:
+    image: envoyproxy/envoy:v1.31-latest
+    hostname: envoy
+    ports:
+      - "10000:10000"
+    volumes:
+      - ./envoy.yaml:/etc/envoy/envoy.yaml
+      - ./target/wasm32-wasi/release:/etc/envoy/proxy-wasm-plugins
+    networks:
+      - envoymesh
+    depends_on:
+      - httpbin
+  httpbin:
+    image: mccutchen/go-httpbin
+    hostname: httpbin
+    ports:
+      - "8080:8080"
+    networks:
+      - envoymesh
+networks:
+  envoymesh: {}

examples/http_parallel_call/envoy.yaml

@@ -0,0 +1,68 @@
+# Copyright 2022 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.
+
+static_resources:
+  listeners:
+    address:
+      socket_address:
+        address: 0.0.0.0
+        port_value: 10000
+    filter_chains:
+      - filters:
+          - name: envoy.filters.network.http_connection_manager
+            typed_config:
+              "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
+              stat_prefix: ingress_http
+              codec_type: AUTO
+              route_config:
+                name: local_routes
+                virtual_hosts:
+                  - name: local_service
+                    domains:
+                      - "*"
+                    routes:
+                      - match:
+                          prefix: "/"
+                        route:
+                          cluster: httpbin
+              http_filters:
+                - name: envoy.filters.http.wasm
+                  typed_config:
+                    "@type": type.googleapis.com/udpa.type.v1.TypedStruct
+                    type_url: type.googleapis.com/envoy.extensions.filters.http.wasm.v3.Wasm
+                    value:
+                      config:
+                        name: "http_parallel_call"
+                        vm_config:
+                          runtime: "envoy.wasm.runtime.v8"
+                          code:
+                            local:
+                              filename: "/etc/envoy/proxy-wasm-plugins/proxy_wasm_example_http_parallel_call.wasm"
+                - name: envoy.filters.http.router
+                  typed_config:
+                    "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
+  clusters:
+    - name: httpbin
+      connect_timeout: 5s
+      type: STRICT_DNS
+      lb_policy: ROUND_ROBIN
+      load_assignment:
+        cluster_name: httpbin
+        endpoints:
+          - lb_endpoints:
+              - endpoint:
+                  address:
+                    socket_address:
+                      address: httpbin
+                      port_value: 8080

examples/http_parallel_call/src/lib.rs

@@ -0,0 +1,129 @@
+// 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.
+
+use proxy_wasm::hostcalls;
+use proxy_wasm::promise::Promise;
+use proxy_wasm::traits::*;
+use proxy_wasm::types::*;
+use std::collections::HashMap;
+use std::rc::Rc;
+use std::time::Duration;
+
+proxy_wasm::main! {{
+    proxy_wasm::set_log_level(LogLevel::Trace);
+    proxy_wasm::set_http_context(|_, _| -> Box<dyn HttpContext> { Box::new(HttpParallelCall::default()) });
+}}
+
+#[derive(Default)]
+struct HttpParallelCall {
+    m: HashMap<u32, Rc<Promise<(u32, usize, usize, usize)>>>,
+}
+
+impl HttpContext for HttpParallelCall {
+    fn on_http_request_headers(&mut self, _: usize, _: bool) -> Action {
+        // "Hello, "
+        let token1 = self
+            .dispatch_http_call(
+                "httpbin",
+                vec![
+                    (":method", "GET"),
+                    (":path", "/base64/SGVsbG8sIAo="),
+                    (":authority", "httpbin.org"),
+                ],
+                None,
+                vec![],
+                Duration::from_secs(1),
+            )
+            .unwrap();
+
+        // "World!"
+        let token2 = self
+            .dispatch_http_call(
+                "httpbin",
+                vec![
+                    (":method", "GET"),
+                    (":path", "/base64/V29ybGQhCg=="),
+                    (":authority", "httpbin.org"),
+                ],
+                None,
+                vec![],
+                Duration::from_secs(1),
+            )
+            .unwrap();
+
+        let promise1 = Promise::new();
+        let promise2 = Promise::new();
+        self.m.insert(token1, promise1.clone());
+        self.m.insert(token2, promise2.clone());
+
+        Promise::all_of(vec![
+            promise1
+                .then(|(_, _, _body_size, _)| get_http_call_response_body_string(0, _body_size))
+                .then(|body| body.unwrap_or_else(|| "".to_string())),
+            promise2
+                .then(|(_, _, _body_size, _)| get_http_call_response_body_string(0, _body_size))
+                .then(|body| body.unwrap_or_else(|| "".to_string())),
+        ])
+        .then(|results| {
+            send_http_response(
+                200,
+                vec![],
+                Some(
+                    format!(
+                        "{}{}\n",
+                        results[0].strip_suffix("\n").unwrap(),
+                        results[1].strip_suffix("\n").unwrap()
+                    )
+                    .as_bytes(),
+                ),
+            );
+        });
+
+        Action::Pause
+    }
+
+    fn on_http_response_headers(&mut self, _: usize, _: bool) -> Action {
+        self.set_http_response_header("Powered-By", Some("proxy-wasm"));
+        Action::Continue
+    }
+}
+
+impl Context for HttpParallelCall {
+    fn on_http_call_response(
+        &mut self,
+        _token_id: u32,
+        _num_headers: usize,
+        _body_size: usize,
+        _num_trailers: usize,
+    ) {
+        let promise = self.m.remove(&_token_id);
+        promise
+            .unwrap()
+            .fulfill((_token_id, _num_headers, _body_size, _num_trailers));
+    }
+}
+
+fn get_http_call_response_body_string(start: usize, max_size: usize) -> Option<String> {
+    match hostcalls::get_buffer(BufferType::HttpCallResponseBody, start, max_size).unwrap() {
+        None => None,
+        Some(bytes) => {
+            let body_string = String::from_utf8(bytes.to_vec()).unwrap();
+            Some(body_string)
+        }
+    }
+}
+
+fn send_http_response(status_code: u32, headers: Vec<(&str, &str)>, body: Option<&[u8]>) {
+    hostcalls::send_http_response(status_code, headers, body).unwrap()
+}

src/lib.rs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 pub mod hostcalls;
+pub mod promise;
 pub mod traits;
 pub mod types;