Add simple stats API

.github/workflows/rust.yml

@@ -238,6 +238,7 @@ jobs:
         - 'http_body'
         - 'http_config'
         - 'http_headers'
+        - 'metrics'
 
     defaults:
       run:
@@ -301,6 +302,7 @@ jobs:
         - 'http_body'
         - 'http_config'
         - 'http_headers'
+        - 'metrics'
 
     defaults:
       run:

README.md

@@ -21,6 +21,7 @@
 - [HTTP Headers](./examples/http_headers/)
 - [HTTP Response body](./examples/http_body/)
 - [HTTP Configuration](./examples/http_config/)
+- [Metrics](./examples/metrics/)
 
 ## Articles & blog posts from the community
 

examples/metrics/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+publish = false
+name = "proxy-wasm-example-metrics"
+version = "0.0.1"
+authors = ["José Ulises Niño Rivera <[email protected]>"]
+description = "Proxy-Wasm plugin example: Metrics"
+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/metrics/README.md

@@ -0,0 +1,32 @@
+## Proxy-Wasm plugin example: HTTP headers
+
+Proxy-Wasm plugin that logs HTTP request/response headers.
+
+### 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
+```
+
+Send HTTP request to `localhost:10000/`:
+
+```sh
+$ curl localhost:10000/ -H "x-envoy-wasm-metric-value: 100" -H "x-envoy-wasm-metric: gauge"
+```
+
+For instance that request will set the example gauge to 100. Which you can see using the stats endpoint
+
+```sh
+& curl -s localhost:9001/stats | grep wasmcustom.wasm_gauge
+
+100
+```

examples/metrics/docker-compose.yaml

@@ -0,0 +1,28 @@
+# 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:v1.24-latest
+    hostname: envoy
+    ports:
+      - "10000:10000"
+      - "9001:9001"
+    volumes:
+      - ./envoy.yaml:/etc/envoy/envoy.yaml
+      - ./target/wasm32-wasi/release:/etc/envoy/proxy-wasm-plugins
+    networks:
+      - envoymesh
+networks:
+  envoymesh: {}

examples/metrics/envoy.yaml

@@ -0,0 +1,61 @@
+# 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: "/"
+                        direct_response:
+                          status: 200
+                          body:
+                            inline_string: "Request /hello and be welcomed!\n"
+              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_headers"
+                        vm_config:
+                          runtime: "envoy.wasm.runtime.v8"
+                          code:
+                            local:
+                              filename: "/etc/envoy/proxy-wasm-plugins/proxy_wasm_example_metrics.wasm"
+                - name: envoy.filters.http.router
+                  typed_config:
+                    "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
+
+admin:
+   profile_path: /tmp/envoy.prof
+   address:
+     socket_address: { address: 0.0.0.0, port_value: 9001 }

examples/metrics/src/lib.rs

@@ -0,0 +1,86 @@
+// 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::stats;
+use proxy_wasm::traits::*;
+use proxy_wasm::types::*;
+
+use std::convert::TryInto;
+
+proxy_wasm::main! {{
+    proxy_wasm::set_log_level(LogLevel::Trace);
+    proxy_wasm::set_root_context(|_| -> Box<dyn RootContext> { Box::new(
+        MetricsRootContext {
+            metrics: WasmMetrics {
+                counter: stats::Counter::new(String::from("wasm_counter")),
+                gauge: stats::Gauge::new(String::from("wasm_gauge")),
+                histogram: stats::Histogram::new(String::from("wasm_histogram")),
+            }
+        }
+    )});
+}}
+
+#[derive(Copy, Clone)]
+struct WasmMetrics {
+    counter: stats::Counter,
+    gauge: stats::Gauge,
+    histogram: stats::Histogram,
+}
+
+struct MetricsRootContext {
+    metrics: WasmMetrics,
+}
+
+impl Context for MetricsRootContext {}
+
+impl RootContext for MetricsRootContext {
+    fn get_type(&self) -> Option<ContextType> {
+        Some(ContextType::HttpContext)
+    }
+
+    fn create_http_context(&self, _: u32) -> Option<Box<dyn HttpContext>> {
+        Some(Box::new(StreamContext {
+            metrics: self.metrics,
+        }))
+    }
+}
+
+struct StreamContext {
+    metrics: WasmMetrics,
+}
+
+impl Context for StreamContext {}
+
+impl HttpContext for StreamContext {
+    fn on_http_request_headers(&mut self, _: usize, _: bool) -> Action {
+        let value = match self.get_http_request_header("x-envoy-wasm-metric-value") {
+            Some(value) => value.parse::<i64>().unwrap(),
+            _ => 0,
+        };
+
+        let metric_type = match self.get_http_request_header("x-envoy-wasm-metric") {
+            Some(metric_type) => metric_type,
+            _ => return Action::Continue,
+        };
+
+        match metric_type.as_str() {
+            "counter" => self.metrics.counter.increment(value),
+            "gauge" => self.metrics.gauge.record(value.try_into().unwrap()),
+            "histogram" => self.metrics.histogram.record(value.try_into().unwrap()),
+            _ => return Action::Continue,
+        }
+
+        Action::Continue
+    }
+}

src/lib.rs

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

src/stats.rs

@@ -0,0 +1,80 @@
+// 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 crate::hostcalls;
+use crate::traits;
+use crate::types;
+
+#[derive(Copy, Clone)]
+pub struct Counter {
+    id: u32,
+}
+
+impl Counter {
+    pub fn new(name: String) -> Counter {
+        let returned_id = hostcalls::define_metric(types::MetricType::Counter, &name)
+            .expect("failed to define counter '{}', name");
+        Counter { id: returned_id }
+    }
+}
+
+impl traits::Metric for Counter {
+    fn id(&self) -> u32 {
+        self.id
+    }
+}
+
+impl traits::IncrementingMetric for Counter {}
+
+#[derive(Copy, Clone)]
+pub struct Gauge {
+    id: u32,
+}
+
+impl Gauge {
+    pub fn new(name: String) -> Gauge {
+        let returned_id = hostcalls::define_metric(types::MetricType::Gauge, &name)
+            .expect("failed to define gauge '{}', name");
+        Gauge { id: returned_id }
+    }
+}
+
+impl traits::Metric for Gauge {
+    fn id(&self) -> u32 {
+        self.id
+    }
+}
+
+impl traits::RecordingMetric for Gauge {}
+
+#[derive(Copy, Clone)]
+pub struct Histogram {
+    id: u32,
+}
+
+impl Histogram {
+    pub fn new(name: String) -> Histogram {
+        let returned_id = hostcalls::define_metric(types::MetricType::Histogram, &name)
+            .expect("failed to define histogram '{}', name");
+        Histogram { id: returned_id }
+    }
+}
+
+impl traits::Metric for Histogram {
+    fn id(&self) -> u32 {
+        self.id
+    }
+}
+
+impl traits::RecordingMetric for Histogram {}

src/traits.rs

@@ -534,3 +534,35 @@ pub trait HttpContext: Context {
 
     fn on_log(&mut self) {}
 }
+
+pub trait Metric {
+    fn id(&self) -> u32;
+
+    fn value(&self) -> u64 {
+        match hostcalls::get_metric(self.id()) {
+            Ok(value) => value,
+            Err(Status::NotFound) => panic!("metric not found: {}", self.id()),
+            Err(err) => panic!("unexpected status: {:?}", err),
+        }
+    }
+}
+
+pub trait IncrementingMetric: Metric {
+    fn increment(&self, offset: i64) {
+        match hostcalls::increment_metric(self.id(), offset) {
+            Ok(_) => return,
+            Err(Status::NotFound) => panic!("metric not found: {}", self.id()),
+            Err(err) => panic!("unexpected status: {:?}", err),
+        }
+    }
+}
+
+pub trait RecordingMetric: Metric {
+    fn record(&self, value: u64) {
+        match hostcalls::record_metric(self.id(), value) {
+            Ok(_) => return,
+            Err(Status::NotFound) => panic!("metric not found: {}", self.id()),
+            Err(err) => panic!("unexpected status: {:?}", err),
+        }
+    }
+}