Add actix-http-tracing example (open-telemetry#373)

Author: jtescher

Cargo.toml

@@ -7,15 +7,16 @@ members = [
     "opentelemetry-prometheus",
     "opentelemetry-semantic-conventions",
     "opentelemetry-zipkin",
-    "examples/actix-udp",
     "examples/actix-http",
+    "examples/actix-http-tracing",
+    "examples/actix-udp",
     "examples/async",
     "examples/aws-xray",
     "examples/basic",
     "examples/basic-otlp",
     "examples/datadog",
     "examples/grpc",
     "examples/http",
+    "examples/tracing-grpc",
     "examples/zipkin",
-    "examples/tracing-grpc"
 ]

examples/actix-http-tracing/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "actix-http-tracing"
+version = "0.1.0"
+edition = "2018"
+publish = false
+
+[dependencies]
+actix-web = "3.2"
+actix-web-opentelemetry = { version = "0.8", features = ["metrics"] }
+opentelemetry = { version = "0.10", features = ["metrics", "tokio"] }
+opentelemetry-jaeger = { version = "0.9", features = ["tokio"] }
+opentelemetry-prometheus = "0.3.0"
+tracing = "0.1"
+tracing-opentelemetry = "0.9"
+tracing-subscriber = "0.2"

examples/actix-http-tracing/README.md

@@ -0,0 +1,72 @@
+# Actix Web with Tracing example
+
+This example shows how to export data to [Jaeger] and [Prometheus] from an
+[actix-web] app instrumented using the [tracing] API and ecosystem.
+
+[Jaeger]: https://www.jaegertracing.io
+[Prometheus]: https://prometheus.io
+[actix-web]: https://github.com/actix/actix-web
+[tracing]: https://github.com/tokio-rs/tracing
+
+## Setup
+
+```shell
+# Run jaeger in background
+$ docker run -d -p6831:6831/udp -p6832:6832/udp -p16686:16686 -p14268:14268 jaegertracing/all-in-one:latest
+
+# Start the actix web server
+$ cargo run
+
+# (from another terminal window)
+$ curl localhost:8080/users/@ferris
+=> Hello @ferris
+
+# View spans (see the image below)
+$ firefox http://localhost:16686/
+```
+
+## Generated Telemetry
+
+### Jaeger
+
+After completing the steps above, the following trace information is now
+available:
+
+![Jaeger UI](trace.png)
+
+### Prometheus (Optional)
+
+Optional request metrics information is now exposed via `/metrics`:
+
+```shell
+$ curl localhost:8080/metrics
+
+# HELP http_requests_duration HTTP request duration per route
+# TYPE http_requests_duration histogram
+http_requests_duration_bucket{method="GET",route="/users/{username}",status="200",le="0.5"} 1
+http_requests_duration_bucket{method="GET",route="/users/{username}",status="200",le="0.9"} 1
+http_requests_duration_bucket{method="GET",route="/users/{username}",status="200",le="0.99"} 1
+http_requests_duration_bucket{method="GET",route="/users/{username}",status="200",le="+Inf"} 1
+http_requests_duration_sum{method="GET",route="/users/{username}",status="200"} 0.001289
+http_requests_duration_count{method="GET",route="/users/{username}",status="200"} 1
+# HELP http_requests_total HTTP requests per route
+# TYPE http_requests_total counter
+http_requests_total{method="GET",route="/users/{username}",status="200"} 1
+```
+
+### Logs
+
+[tracing] has been configured to report `INFO` and above level logs to stdout
+via [`tracing_subscriber::fmt`] and [`tracing_subscriber::EnvFilter`] to produce
+the output below:
+
+```shell
+Nov 29 13:08:04.932  INFO actix_server::builder: Starting 16 workers
+Nov 29 13:08:04.933  INFO actix_server::builder: Starting "actix-web-service-127.0.0.1:8080" service on 127.0.0.1:8080
+Nov 29 13:08:08.740  INFO greet_user{username="@ferris"}: actix_http_tracing: preparing to greet user
+Nov 29 13:08:08.740  INFO actix_web::middleware::logger: 127.0.0.1:63418 "GET /users/@ferris HTTP/1.1" 200 13 "-" "curl/7.64.1" 0.000758
+```
+
+[tracing]: https://github.com/tokio-rs/tracing
+[`tracing_subscriber::fmt`]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/fmt/index.html
+[`tracing_subscriber::EnvFilter`]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html

examples/actix-http-tracing/src/main.rs

@@ -0,0 +1,56 @@
+use actix_web::middleware::Logger;
+use actix_web::{web, App, HttpServer};
+use actix_web_opentelemetry::RequestTracing;
+use opentelemetry::{global, sdk::propagation::TraceContextPropagator};
+use std::io;
+use tracing_subscriber::prelude::*;
+use tracing_subscriber::Registry;
+
+async fn index(username: actix_web::web::Path<String>) -> String {
+    greet_user(username.as_ref())
+}
+
+#[tracing::instrument]
+fn greet_user(username: &str) -> String {
+    tracing::info!("preparing to greet user");
+    format!("Hello {}", username)
+}
+
+#[actix_web::main]
+async fn main() -> io::Result<()> {
+    // Start an (optional) otel prometheus metrics pipeline
+    let metrics_exporter = opentelemetry_prometheus::exporter().init();
+    let request_metrics = actix_web_opentelemetry::RequestMetrics::new(
+        opentelemetry::global::meter("actix_http_tracing"),
+        Some(|req: &actix_web::dev::ServiceRequest| {
+            req.path() == "/metrics" && req.method() == actix_web::http::Method::GET
+        }),
+        Some(metrics_exporter),
+    );
+
+    // Start an otel jaeger trace pipeline
+    global::set_text_map_propagator(TraceContextPropagator::new());
+    let (tracer, _uninstall) = opentelemetry_jaeger::new_pipeline()
+        .with_service_name("app_name")
+        .install()
+        .unwrap();
+
+    // Initialize `tracing` using `opentelemetry-tracing` and configure logging
+    Registry::default()
+        .with(tracing_subscriber::EnvFilter::new("INFO"))
+        .with(tracing_subscriber::fmt::layer())
+        .with(tracing_opentelemetry::layer().with_tracer(tracer))
+        .init();
+
+    // Start actix web with otel and tracing middlewares
+    HttpServer::new(move || {
+        App::new()
+            .wrap(Logger::default())
+            .wrap(RequestTracing::new())
+            .wrap(request_metrics.clone())
+            .service(web::resource("/users/{username}").to(index))
+    })
+    .bind("127.0.0.1:8080")?
+    .run()
+    .await
+}