From db6a62ff2883a05d396de9c6d9f43f7ca046105a Mon Sep 17 00:00:00 2001
From: Jose Celano <josecelano@gmail.com>
Date: Mon, 12 Feb 2024 17:04:11 +0000
Subject: [PATCH] chore: [#468] set and propagate request ID

It propagates the request ID to the response.

If the request does not have an ID it sets a newly
generated UUID.

Without providing ID:

```
$ curl -i localhost:3001/v1/about/license
HTTP/1.1 200 OK
content-type: text/html; charset=utf-8
content-length: 1262
x-request-id: cea0efcd-84e0-4f59-96b3-625ca4154396
date: Mon, 12 Feb 2024 16:58:05 GMT
```

Providing ID:

```
$ curl -i -H "x-request-id: a5030c7a-5302-49d4-8e66-f0f0ab0e3ce3" localhost:3001/v1/about/license
HTTP/1.1 200 OK
content-type: text/html; charset=utf-8
content-length: 1262
x-request-id: a5030c7a-5302-49d4-8e66-f0f0ab0e3ce3
date: Mon, 12 Feb 2024 16:59:31 GMT
```

The response contains the provided ID in the request.
---
 src/web/api/server/v1/routes.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/web/api/server/v1/routes.rs b/src/web/api/server/v1/routes.rs
index 76be1b14..b9150870 100644
--- a/src/web/api/server/v1/routes.rs
+++ b/src/web/api/server/v1/routes.rs
@@ -3,14 +3,19 @@ use std::env;
 use std::sync::Arc;
 
 use axum::extract::DefaultBodyLimit;
+use axum::http::{HeaderName, HeaderValue};
 use axum::response::Redirect;
 use axum::routing::get;
 use axum::{Json, Router};
+use hyper::Request;
 use serde_json::{json, Value};
 use tower_http::compression::CompressionLayer;
 use tower_http::cors::CorsLayer;
+use tower_http::propagate_header::PropagateHeaderLayer;
+use tower_http::request_id::{MakeRequestId, RequestId, SetRequestIdLayer};
 use tower_http::trace::{DefaultMakeSpan, DefaultOnRequest, DefaultOnResponse, TraceLayer};
 use tracing::Level;
+use uuid::Uuid;
 
 use super::contexts::{about, category, proxy, settings, tag, torrent, user};
 use crate::bootstrap::config::ENV_VAR_CORS_PERMISSIVE;
@@ -57,6 +62,8 @@ pub fn router(app_data: Arc<AppData>) -> Router {
                 .on_request(DefaultOnRequest::new().level(Level::INFO))
                 .on_response(DefaultOnResponse::new().level(Level::INFO)),
         )
+        .layer(PropagateHeaderLayer::new(HeaderName::from_static("x-request-id")))
+        .layer(SetRequestIdLayer::x_request_id(RequestIdGenerator))
 }
 
 /// Endpoint for container health check.
@@ -67,3 +74,13 @@ async fn health_check_handler() -> Json<Value> {
 async fn redirect_to_about() -> Redirect {
     Redirect::permanent(&format!("/{API_VERSION_URL_PREFIX}/about"))
 }
+
+#[derive(Clone, Default)]
+struct RequestIdGenerator;
+
+impl MakeRequestId for RequestIdGenerator {
+    fn make_request_id<B>(&mut self, _request: &Request<B>) -> Option<RequestId> {
+        let id = HeaderValue::from_str(&Uuid::new_v4().to_string()).expect("UUID is a valid HTTP header value");
+        Some(RequestId::new(id))
+    }
+}