https://github.com/fast/fastrace-reqwest
A reqwest util for propagating trace context for fastrace.
https://github.com/fast/fastrace-reqwest
Last synced: 11 months ago
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A reqwest util for propagating trace context for fastrace.
- Host: GitHub
- URL: https://github.com/fast/fastrace-reqwest
- Owner: fast
- License: apache-2.0
- Created: 2025-03-18T10:56:00.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2025-05-13T15:01:18.000Z (about 1 year ago)
- Last Synced: 2025-06-22T20:44:36.700Z (about 1 year ago)
- Language: Rust
- Homepage:
- Size: 60.5 KB
- Stars: 2
- Watchers: 2
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# fastrace-reqwest
[](https://crates.io/crates/fastrace-reqwest)
[](https://docs.rs/fastrace-reqwest/)
[](https://www.whatrustisit.com)
[](https://github.com/fast/fastrace-reqwest/actions)
[](https://github.com/fast/fastrace-reqwest/blob/main/LICENSE)
Distributed tracing integration for [reqwest](https://crates.io/crates/reqwest) HTTP client requests with [fastrace](https://crates.io/crates/fastrace).
## Overview
`fastrace-reqwest` provides automatic trace context propagation for HTTP requests made with the `reqwest` client. It works seamlessly with the `fastrace` library to extract and inject trace context into outgoing requests.
## What is Context Propagation?
Context propagation is a fundamental concept in distributed tracing that enables the correlation of operations spanning multiple services. When a request moves from one service to another, trace context information needs to be passed along, ensuring that all operations are recorded as part of the same trace.
`fastrace-reqwest` implements the [W3C Trace Context](https://www.w3.org/TR/trace-context/) standard for propagating trace information between services. This ensures compatibility with other tracing systems that follow the same standard.
## Features
- 🔄 **Automatic Context Propagation**: Automatically inject trace context into outgoing HTTP requests.
- 🌉 **Seamless Integration**: Works seamlessly with the `fastrace` library for complete distributed tracing.
- 📊 **Full Compatibility**: Works with fastrace's collection and reporting capabilities.
## Installation
Add to your `Cargo.toml`:
```toml
[dependencies]
fastrace = "0.7"
fastrace-reqwest = "0.2"
```
## Usage
### HTTP Client
```rust
use fastrace::prelude::*;
use fastrace_reqwest::traceparent_headers;
use reqwest::Client;
#[fastrace::trace]
async fn send_request() {
let client = Client::new();
// Add trace context headers to your request.
let response = client
.get("https://api.example.com/data")
.headers(traceparent_headers())
.send()
.await
.unwrap();
// Process response...
}
```
## How It Works
`fastrace-reqwest` enables automatic propagation of trace context between services by:
1. **Extracting** the current trace context from the calling function.
2. **Formatting** it according to the W3C Trace Context specification.
3. **Injecting** it into outgoing HTTP requests as headers
4. Working seamlessly with the companion `fastrace-poem` library (or other compatible frameworks) to extract the context on the receiving end.
### Complete Example
Check out the [examples directory](https://github.com/fast/fastrace-reqwest/tree/main/examples) for complete working examples showing:
- `client.rs` - How to send requests with trace context.
- `server.rs` - How to receive and process trace context using `fastrace-poem`.
To run the examples:
```bash
# First start the server
cargo run --example server
# Then in another terminal, run the client
cargo run --example client
```
## How It Works
1. When making an HTTP request, `traceparent_headers()` checks for a current span context.
2. If found, it encodes the context as a `traceparent` HTTP header following the W3C standard.
3. The receiving service extracts this header and continues the trace.
## License
This project is licensed under the [Apache-2.0](./LICENSE) license.