[rust/warp] implement image service

rust/ms_warp/src/bin/image.rs

@@ -0,0 +1,99 @@
+#![feature(iter_intersperse)]
+
+use warp::Filter;
+use ms_warp::auth;
+
+// Mimic https://docs.openstack.org/api-ref/image/v2/index.html
+
+// The database for images
+const IMGS_DB: &'static[&'static str]  = &["cirros", "debian-10",];
+
+/// Accepts and returns the image name if it exists, reject the
+/// request with a 404 Not found otherwise.
+async fn image_exists(img: String) -> Result<String, warp::Rejection> {
+    let exists = IMGS_DB.iter().any(|&img| img == img);
+
+    if exists {
+        Ok(img)
+    } else {
+        Err(warp::reject::not_found())
+    }
+}
+
+#[tokio::main]
+async fn main() {
+    // List available images
+    //
+    // API:
+    // - / => 200 OK, with images as a json list.
+    //     => 401 Unauthorized, for bad Bearer token
+    //     => 400 Bad request, for missing Bearer token
+    //
+    // Example:
+    // $ curl --oauth2-bearer the-secret-token "127.0.0.1:4202/images/" -v
+    // < HTTP/1.1 200 OK
+    // < ...
+    // ["cirros","debian-10"]%
+    let list = warp::path::end()
+        .and(warp::get())
+        // Collect image names and returns them as a json
+        .map(|| warp::reply::json(&IMGS_DB));
+
+    // Show an image info
+    //
+    // API:
+    // - /:img => 200 OK, with images as a json list.
+    //         => 404 Not found, for an unexisting image.
+    //         => 401 Unauthorized, for bad Bearer token
+    //         => 400 Bad request, for missing Bearer token
+    //
+    // Example:
+    // $ curl --oauth2-bearer the-secret-token "127.0.0.1:4202/images/debian-10" -v
+    // < HTTP/1.1 200 OK
+    // < ...
+    // ...
+    let show = warp::path!(String)
+        .and(warp::get())
+        .and_then(image_exists)
+        .map(|_img: String| {
+            // TODO: build `_img` info
+            let img_info = "";
+            warp::reply::json(&img_info)
+        });
+
+    // Get image data stream
+    //
+    // API:
+    // - /:img/file => 200 OK, with images as a json list.
+    //              => 404 Not found, for an unexisting image.
+    //              => 401 Unauthorized, for bad Bearer token
+    //              => 400 Bad request, for missing Bearer token
+    //
+    // Example:
+    // curl --oauth2-bearer the-secret-token http://localhost:4202/images/debian-10/file -v
+    // < HTTP/1.1 200 OK
+    // < ...
+    // ...
+    let get_data = warp::path!(String / "file")
+        .and(warp::get())
+        .and_then(image_exists)
+        .map(|_img: String| {
+            // TODO: get `_img` data
+            let img_data: &'static [u8] = &[];
+            warp::reply::html(img_data)
+        });
+
+    // Define the API (prefix every path with "images")
+    let api = warp::path("images")
+        // Check token validity
+        .and(auth::authorized())
+        // Compose endpoints
+        .and(list
+             .or(show)
+             .or(get_data))
+        // Return good response code for authorization
+        .recover(auth::handle_not_authorized);
+
+    // Start the server
+    warp::serve(api).run(([0,0,0,0], 4202)).await;
+}