Add Host extractor

axum/src/extract/host.rs

@@ -0,0 +1,59 @@
+use super::{FromRequest, RequestParts};
+use async_trait::async_trait;
+use std::{convert::Infallible};
+
+/// Extractor that extracts the host from a request.
+#[derive(Debug, Clone, Default)]
+pub struct Host(pub String);
+
+#[async_trait]
+impl<B> FromRequest<B> for Host
+where
+    B: Send,
+{
+    type Rejection = Infallible;
+
+    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
+        if let Some(host) = req.uri().host() {
+            return Ok(Host(host.to_string()));
+        }
+
+        if let Some(Ok(host)) = req.headers().get("host").map(|host| host.to_str()) {
+            return Ok(Host(host.to_string()));
+        }
+
+        Ok(Host("".to_string()))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::extract::RequestParts;
+    use http::Request;
+
+    #[tokio::test]
+    async fn test_host() {
+        let mut req = RequestParts::new(
+            Request::builder()
+                .uri("http://example.com/test")
+                .body(())
+                .unwrap(),
+        );
+        assert_eq!(
+            &Host::from_request(&mut req).await.unwrap().0,
+            "example.com"
+        );
+
+        let mut req = RequestParts::new(
+            Request::builder()
+                .header("host", "cats.fun")
+                .body(())
+                .unwrap(),
+        );
+        assert_eq!(
+            &Host::from_request(&mut req).await.unwrap().0,
+            "cats.fun"
+        );
+    }
+}

axum/src/extract/mod.rs

@@ -28,6 +28,8 @@ pub use self::{
     request_parts::{BodyStream, RawBody},
 };
 
+pub mod host;
+
 #[doc(no_inline)]
 #[cfg(feature = "json")]
 pub use crate::Json;