# Ottofeller telemetry library

This crate contains the API for telemetry setup in Rust.

## Overview

This crate supplements [tracing](https://crates.io/crates/tracing) library and provides an easy way to setup providers for collection of logs, metrics and traces.

### What does this crate contain?

- **Telemetry API:**
  Provides a way to setup collection of logs, metrics and traces with a choice of preconfigured providers.
  
The other modules are provide a way to fine-tune telemetry during setup. They contain reasonable defalts as well as allow configuration in the scope of exposed API. 

- **Logs:**
  A collection of log providers. Available options are `Stdout` and `Stderr`.
- **Metrics:**
  A collection of log providers. Available options are `Stdout` and `CloudWatch`.
- **Traces:**
  A collection of log providers. Available options are `Stdout` and `Xray`.

## Getting started

To have the telemetry collected one needs to:
- setup providers for each type of telemetry;
- instrument the code with relevant events.

### Setup telemetry
```rust
use metry::telemetry;

telemetry::new()
    .with_stdout_logs()
    .with_aws_metrics()
    .with_aws_traces()
    .init()
    .await;
```

### Instrument your code
```rust
use tracing::{info, info_span};

// Emit a log event with level info
info!("Started execution");

// Start a synchronous trace span
let span = info_span!("my sync span");
span.in_scope(|| {
    info!("This event is recorder within the trace span");

    // Do work inside the span...

    // Collect metrics: count on foo
    info!(monotonic_counter.foo = 1);
});

// Run async code in a future with a span attached
let future_result: Vec<u64> = some_future
    .instrument(tracing::info_span!("my async span"))
    .await;

// Collect metrics: put data into the bar histogram
info!(histogram.bar = future_result);
info!("Execution complete");
```