Convert to lib+bin crate and fix axum route parameter syntax for 0.7

Adds lib.rs re-exporting all public modules for integration test access.
Refactors main.rs to import from seaweed_volume:: lib crate. Fixes route
parameter syntax from {path} (axum 0.8) to :path (axum 0.7) — the old
brace syntax silently failed to match requests.

seaweed-volume/src/lib.rs

@@ -0,0 +1,18 @@
+pub mod config;
+pub mod storage;
+pub mod security;
+pub mod server;
+pub mod metrics;
+
+/// Generated protobuf modules.
+pub mod pb {
+    pub mod remote_pb {
+        tonic::include_proto!("remote_pb");
+    }
+    pub mod volume_server_pb {
+        tonic::include_proto!("volume_server_pb");
+    }
+    pub mod master_pb {
+        tonic::include_proto!("master_pb");
+    }
+}

seaweed-volume/src/main.rs

@@ -1,32 +1,15 @@
-mod config;
-mod storage;
-mod security;
-mod server;
-
-/// Generated protobuf modules.
-pub mod pb {
-    pub mod remote_pb {
-        tonic::include_proto!("remote_pb");
-    }
-    pub mod volume_server_pb {
-        tonic::include_proto!("volume_server_pb");
-    }
-    pub mod master_pb {
-        tonic::include_proto!("master_pb");
-    }
-}
-
 use std::sync::{Arc, RwLock};
 
 use tracing::{info, error};
 
-use crate::config::VolumeServerConfig;
-use crate::security::{Guard, SigningKey};
-use crate::server::grpc_server::VolumeGrpcService;
-use crate::server::volume_server::VolumeServerState;
-use crate::storage::store::Store;
-use crate::storage::types::DiskType;
-use crate::pb::volume_server_pb::volume_server_server::VolumeServerServer;
+use seaweed_volume::config::{self, VolumeServerConfig};
+use seaweed_volume::metrics;
+use seaweed_volume::security::{Guard, SigningKey};
+use seaweed_volume::server::grpc_server::VolumeGrpcService;
+use seaweed_volume::server::volume_server::VolumeServerState;
+use seaweed_volume::storage::store::Store;
+use seaweed_volume::storage::types::DiskType;
+use seaweed_volume::pb::volume_server_pb::volume_server_server::VolumeServerServer;
 
 fn main() {
     // Initialize tracing
@@ -40,6 +23,9 @@ fn main() {
     let config = config::parse_cli();
     info!("SeaweedFS Volume Server (Rust) v{}", env!("CARGO_PKG_VERSION"));
 
+    // Register Prometheus metrics
+    metrics::register_metrics();
+
     // Build the tokio runtime and run the async entry point
     let rt = tokio::runtime::Builder::new_multi_thread()
         .enable_all()
@@ -94,7 +80,7 @@ async fn run(config: VolumeServerConfig) {
     });
 
     // Build HTTP routers
-    let admin_router = server::volume_server::build_admin_router(state.clone());
+    let admin_router = seaweed_volume::server::volume_server::build_admin_router(state.clone());
     let admin_addr = format!("{}:{}", config.bind_ip, config.port);
 
     let public_port = config.public_port;
@@ -160,7 +146,7 @@ async fn run(config: VolumeServerConfig) {
     });
 
     let public_handle = if needs_public {
-        let public_router = server::volume_server::build_public_router(state.clone());
+        let public_router = seaweed_volume::server::volume_server::build_public_router(state.clone());
         let public_addr = format!("{}:{}", config.bind_ip, public_port);
         let listener = tokio::net::TcpListener::bind(&public_addr)
             .await

seaweed-volume/src/server/volume_server.rs

@@ -30,9 +30,10 @@ pub fn build_admin_router(state: Arc<VolumeServerState>) -> Router {
     Router::new()
         .route("/status", get(handlers::status_handler))
         .route("/healthz", get(handlers::healthz_handler))
+        .route("/metrics", get(handlers::metrics_handler))
         // Volume operations: GET/HEAD/POST/PUT/DELETE on /{vid},{fid}
         .route(
-            "/{path}",
+            "/:path",
             get(handlers::get_or_head_handler)
                 .head(handlers::get_or_head_handler)
                 .post(handlers::post_handler)
@@ -41,7 +42,7 @@ pub fn build_admin_router(state: Arc<VolumeServerState>) -> Router {
         )
         // Also support /{vid}/{fid} and /{vid}/{fid}/{filename} paths
         .route(
-            "/{vid}/{fid}",
+            "/:vid/:fid",
             get(handlers::get_or_head_handler)
                 .head(handlers::get_or_head_handler)
                 .post(handlers::post_handler)
@@ -49,7 +50,7 @@ pub fn build_admin_router(state: Arc<VolumeServerState>) -> Router {
                 .delete(handlers::delete_handler),
         )
         .route(
-            "/{vid}/{fid}/{filename}",
+            "/:vid/:fid/:filename",
             get(handlers::get_or_head_handler)
                 .head(handlers::get_or_head_handler),
         )
@@ -61,17 +62,17 @@ pub fn build_public_router(state: Arc<VolumeServerState>) -> Router {
     Router::new()
         .route("/healthz", get(handlers::healthz_handler))
         .route(
-            "/{path}",
+            "/:path",
             get(handlers::get_or_head_handler)
                 .head(handlers::get_or_head_handler),
         )
         .route(
-            "/{vid}/{fid}",
+            "/:vid/:fid",
             get(handlers::get_or_head_handler)
                 .head(handlers::get_or_head_handler),
         )
         .route(
-            "/{vid}/{fid}/{filename}",
+            "/:vid/:fid/:filename",
             get(handlers::get_or_head_handler)
                 .head(handlers::get_or_head_handler),
         )