[WIP] OTLP push controller example initial commit

examples/README.md

@@ -12,6 +12,7 @@ cargo run --package example-{name of example}
 - [axum](./axum) - Use autometrics to instrument HTTP handlers
 - [custom-metrics](./custom-metrics/) - Define your own custom metrics alongside the ones generated by autometrics (using any of the metrics collection crates)
 - [exemplars-tracing](./exemplars-tracing/) - Use fields from `tracing::Span`s as Prometheus exemplars
+- [otlp-push-controller](./otlp-push-controller/) - Push autometrics via OTLP gRPC protocol.
 
 ## Full Example
 

examples/otlp-push-controller/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "example-otlp-push-controller"
+version = "0.0.0"
+publish = false
+edition = "2021"
+
+[dependencies]
+autometrics = { path = "../../autometrics", features = ["opentelemetry"] }
+opentelemetry = { version = "0.19", features = ["metrics", "rt-tokio"] }
+opentelemetry-otlp = { version = "0.12", features = ["tonic", "metrics"] }
+opentelemetry-semantic-conventions = { version = "0.11" }
+tokio = { version = "1", features = ["full"] }

examples/otlp-push-controller/README.md

@@ -0,0 +1,30 @@
+# Autometrics + OTLP push controller
+
+This example demonstrates how you can push autometrics via OTLP gRPC protocol to an OTEL-Collector or another compatible solution.
+
+## ⚠️ Warning
+
+At this step, it's absolutely required that the version of the opentelemetry crates used in the project matches the version used as a dependency in `autometrics-rs` crate (See [Issue 91](https://github.com/autometrics-dev/autometrics-rs/issues/91)).
+
+## Running the example
+
+### Start a basic OTEL-Collector
+
+You can use the `otel-collector-config.yaml` file to start an otel-collector container that listen on 0.0.0.0:4317 for incoming otlp-gRPC traffic, and export received metrics to standard output.
+
+```bash
+docker run -d --name otel-col \
+    -p 4317:4317 -p 13133:13133 \
+    -v $PWD/otel-collector-config.yaml:/etc/otelcol/config.yaml \
+    otel/opentelemetry-collector:latest
+```
+
+### Execute example code
+
+```shell
+cargo run -p example-otlp-push-controller
+```
+
+## OpenTelemetry Metrics Push Controller
+
+The metric push controller is implemented as from this [example](https://github.com/open-telemetry/opentelemetry-rust/blob/f20c9b40547ee20b6ec99414bb21abdd3a54d99b/examples/basic-otlp/src/main.rs#L35-L52) from `opentelemetry-rust` crate.

examples/otlp-push-controller/otel-collector-config.yaml

@@ -0,0 +1,19 @@
+receivers:
+  otlp:
+    protocols:
+      grpc:
+        endpoint: 0.0.0.0:4317
+
+exporters:
+  logging:
+    loglevel: debug
+
+processors:
+  batch:
+
+service:
+  pipelines:
+    metrics:
+      receivers: [otlp]
+      processors: []
+      exporters: [logging]

examples/otlp-push-controller/src/main.rs

@@ -0,0 +1,51 @@
+use autometrics::autometrics;
+use opentelemetry::{runtime, Context};
+use opentelemetry::sdk::export::metrics::aggregation::cumulative_temporality_selector;
+use opentelemetry::sdk::metrics::controllers::BasicController;
+use opentelemetry::sdk::metrics::selectors;
+use opentelemetry::metrics;
+use opentelemetry_otlp::{ExportConfig, WithExportConfig};
+use tokio::time::sleep;
+use std::error::Error;
+use std::time::Duration;
+
+fn init_metrics() -> metrics::Result<BasicController> {
+    let export_config = ExportConfig {
+        endpoint: "http://localhost:4317".to_string(),
+        ..ExportConfig::default()
+    };
+    opentelemetry_otlp::new_pipeline()
+        .metrics(
+            selectors::simple::inexpensive(),
+            cumulative_temporality_selector(),
+            runtime::Tokio,
+        )
+        .with_exporter(
+            opentelemetry_otlp::new_exporter()
+                .tonic()
+                .with_export_config(export_config),
+        )
+        .build()
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
+    let meter_provider = init_metrics()?;
+    let cx = Context::current();
+
+    for numb in 0..10 {
+        do_stuff(numb).await;
+    }
+
+    println!("Waiting so that we could see metrics being pushed via OTLP every 10 seconds...");
+    sleep(Duration::from_secs(60)).await;
+    meter_provider.stop(&cx)?;
+
+    Ok(())
+}
+
+#[autometrics]
+async fn do_stuff(numb: u64) {
+    println!("Doing stuff for {} seconds...", numb);
+    sleep(Duration::from_secs(numb)).await;
+}