Module request_id 

One identifier per request, from the first log line to the response header.

When a user reports “it failed around 3pm”, the only thing that connects their screenshot to a line in the log is an identifier that appeared in both. This middleware assigns one — or keeps the one a load balancer already attached — puts it on the request for handlers to read, on the response for the client to quote, and on the http.request instrumentation event for Telescope, the debug bar and OTLP traces.

App::new()?.middleware(RequestId::default())

// In a handler:
let id = req.request_id().unwrap_or("-");

// Anywhere inside the request, without a `Request` in hand:
if let Some(id) = request_id::current() { … }

Incoming identifiers are trusted by default, because the useful case — an edge proxy that stamps every request and logs it — is far more common than the harmful one, and a forged id can do nothing except confuse the forger’s own log search. Anything that does not look like an identifier (too long, not printable ASCII) is replaced rather than passed on.

Structs

Assigned

The identifier assigned to the current request, attached as an extension.

RequestId

Constants

HEADER

The header the identifier travels in, unless configured otherwise.

Functions

current

The identifier of the request this task is serving, if any.

generate

A fresh identifier in the shape of a version-4 UUID.