feat(tvix/nar-bridge): init r/8376

This adds an implementation of nar-bridge in Rust.
Currently, only the GET parts are implemented.

Contrary to the Go variant, this doesn't try to keep a mapping from nar
hashes to root node in memory, it simply encodes the root node itself
(stripped by its basename) into the URL.

This pulls in a more recent version of axum than what we use in
tonic, causing two versions of http and hyper, however dealing with
`Body::from_stream` in axum 0.6 is much more annoying, and
https://github.com/hyperium/tonic/pull/1740 suggests this will be fixed
soon.

Change-Id: Ia4c2dbda7cd3fdbe47a75f3e33544d19eac6e44e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11898
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: Brian Olsen <me@griff.name>
Tested-by: BuildkiteCI

1 files changed, 50 insertions, 0 deletions

diff --git a/tvix/nar-bridge/src/lib.rs b/tvix/nar-bridge/src/lib.rs
new file mode 100644
index 000000000000..5d9ec43c1cde
--- /dev/null
+++ b/tvix/nar-bridge/src/lib.rs
@@ -0,0 +1,50 @@
+use axum::routing::head;
+use axum::{routing::get, Router};
+use std::sync::Arc;
+use tvix_castore::blobservice::BlobService;
+use tvix_castore::directoryservice::DirectoryService;
+use tvix_store::pathinfoservice::PathInfoService;
+
+mod nar;
+mod narinfo;
+
+#[derive(Clone)]
+pub struct AppState {
+    blob_service: Arc<dyn BlobService>,
+    directory_service: Arc<dyn DirectoryService>,
+    path_info_service: Arc<dyn PathInfoService>,
+}
+
+impl AppState {
+    pub fn new(
+        blob_service: Arc<dyn BlobService>,
+        directory_service: Arc<dyn DirectoryService>,
+        path_info_service: Arc<dyn PathInfoService>,
+    ) -> Self {
+        Self {
+            blob_service,
+            directory_service,
+            path_info_service,
+        }
+    }
+}
+
+pub fn gen_router(priority: u64) -> Router<AppState> {
+    Router::new()
+        .route("/", get(root))
+        .route("/nar/tvix-castore/:root_node_enc", get(nar::get))
+        .route("/:narinfo_str", get(narinfo::get))
+        .route("/:narinfo_str", head(narinfo::head))
+        .route("/nix-cache-info", get(move || nix_cache_info(priority)))
+}
+
+async fn root() -> &'static str {
+    "Hello from nar-bridge"
+}
+
+async fn nix_cache_info(priority: u64) -> String {
+    format!(
+        "StoreDir: /nix/store\nWantMassQuery: 1\nPriority: {}\n",
+        priority
+    )
+}