# Rust

Instrument Rust applications with OpenTelemetry

# Integration

Instrument your Rust applications to send traces, logs, and metrics to Kopai.

## Installation

Add to your `Cargo.toml`:

```toml
[dependencies]
opentelemetry = "0.31"
opentelemetry_sdk = { version = "0.31", features = ["rt-tokio"] }
opentelemetry-otlp = { version = "0.31", features = ["http-json"] }
tokio = { version = "1", features = ["full"] }
```

## Basic Setup

```rust
use opentelemetry::global;
use opentelemetry::trace::Tracer;
use opentelemetry_otlp::{Protocol, WithExportConfig};
use opentelemetry_sdk::trace::SdkTracerProvider;
use opentelemetry_sdk::Resource;
use std::env;

fn init_tracer() -> SdkTracerProvider {
    let endpoint = env::var("OTEL_EXPORTER_OTLP_ENDPOINT")
        .unwrap_or_else(|_| "http://localhost:4318".to_string());
    let service_name = env::var("OTEL_SERVICE_NAME")
        .unwrap_or_else(|_| "my-service".to_string());

    let exporter = opentelemetry_otlp::SpanExporter::builder()
        .with_http()
        .with_protocol(Protocol::HttpJson)
        .with_endpoint(format!("{}/v1/traces", endpoint))
        .build()
        .expect("Failed to create exporter");

    let resource = Resource::builder()
        .with_service_name(service_name)
        .build();

    let provider = SdkTracerProvider::builder()
        .with_resource(resource)
        .with_batch_exporter(exporter)
        .build();

    global::set_tracer_provider(provider.clone());
    provider
}

fn main() {
    let provider = init_tracer();
    let tracer = global::tracer("my-app");

    tracer.in_span("my-operation", |_cx| {
        // ... your code
    });

    provider.shutdown().expect("Shutdown failed");
}
```

## Running Your Application

Set the required environment variables and run:

```bash
export OTEL_EXPORTER_OTLP_ENDPOINT="https://otlp-http.kopai.app"
export OTEL_SERVICE_NAME="my-service"
cargo run --release
```

| Variable | Description |
|----------|-------------|
| `OTEL_EXPORTER_OTLP_ENDPOINT` | Kopai OTLP endpoint |
| `OTEL_SERVICE_NAME` | Name shown in Kopai UI |

## Working Example

For a complete working example:

**[Rust Example](https://github.com/kopai-app/kopai-integration-examples/tree/main/rust)**