Add reverse proxy endpoint

src/handlers/mod.rs

@@ -18,8 +18,9 @@ async fn docs() -> &'static str {
     dedent!(
         "
         Welcome to Nyeki's API! This is a tiny API I built to provide some basic information I
-        found myself needing in more than one place. This at the moment only includes Discord and
-        GitHub profiles, but I may add more stuff as I see myself needing it.
+        found myself needing in more than one place. This at the moment only includes Discord
+        profiles, GitHub profiles, and a reverse proxy, but I may add more stuff as I see myself
+        needing it.
 
         The API is versioned, so API endpoints will always be prefixed with `/v{version}`. The
         current version is 1 (i.e. stuff is prefixed by `/v1`). All responses are JSON (or
@@ -88,6 +89,15 @@ async fn docs() -> &'static str {
                             for supported sources).
                 - `source`: The source of the profile (either `discord` or `github`).
 
+            GET /v1/proxy
+                Proxies a request to the given URL.
+
+                Note that headers are not forwarded and neither is the request body. This is a
+                simple GET proxy.
+
+                Query parameters:
+                - `url`: The URL to proxy the request to.
+
         They all take 2 query parameters: `id` and `source`. The `id` is the ID of the user you
         want to get the profile of, and the `source` is the source of the profile. The source can
         be either `discord` or `github`.

src/handlers/v1/mod.rs

@@ -4,10 +4,12 @@ use std::sync::Arc;
 
 use axum::{
     Json, Router,
+    body::{Body, Bytes},
     extract::{Query, State as AxumState},
-    response::Redirect,
+    response::{Redirect, Response},
     routing::get,
 };
+use futures_util::StreamExt;
 use reqwest::Client;
 use serde::{Deserialize, Serialize};
 use turbostore::{Decode, Duration, Encode};
@@ -21,6 +23,7 @@ pub fn router() -> Router<Arc<State>> {
         .route("/profile/avatar", get(get_profile_avatar))
         .route("/profile/banner", get(get_profile_banner))
         .route("/profile/url", get(get_profile_url))
+        .route("/proxy", get(proxy_with_cors))
         .fallback(error_404)
         .method_not_allowed_fallback(error_405)
 }
@@ -300,3 +303,45 @@ async fn get_profile_url(
 
     Ok(Redirect::to(&profile.url))
 }
+
+#[derive(Debug, Deserialize)]
+struct ProxyQuery {
+    url: String,
+}
+
+async fn proxy_with_cors(Query(params): Query<ProxyQuery>) -> Result<Response, Error> {
+    let client = Client::new();
+
+    match client.get(&params.url).send().await {
+        Ok(resp) => {
+            let status = resp.status();
+            let headers = resp.headers().clone();
+
+            // Turn the reqwest response into a streaming body
+            let stream = resp.bytes_stream().map(|chunk_result| match chunk_result {
+                Ok(chunk) => Ok::<Bytes, std::io::Error>(chunk),
+                Err(_) => Err(std::io::Error::other("stream error")),
+            });
+
+            // Convert the stream into a hyper Body
+            let body = Body::from_stream(stream);
+
+            // Build response
+            let mut response = Response::builder().status(status);
+            let headers_mut = response.headers_mut().unwrap();
+            for (key, value) in headers.iter() {
+                // Skip certain headers that hyper will manage itself
+                if key.as_str().eq_ignore_ascii_case("content-length") {
+                    continue;
+                }
+                headers_mut.insert(key, value.clone());
+            }
+
+            Ok(response.body(body).unwrap())
+        }
+        Err(_) => Err(Error {
+            status: 500,
+            message: "Failed to fetch the requested URL".into(),
+        }),
+    }
+}