Hot reload operation files and directories (#69)

Author: Matthew Hawkins

CHANGELOG.md

@@ -16,6 +16,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ## [Unreleased]
 
 ### 🚀 Features
+- The `--operations` argument now supports hot reloading and directory paths. If a directory is specified, all .graphql files in the directory will be loaded as operations. The running server will update when files are added to or removed from the directory. (#69)
 - Add an optional `--sse-address` argument to set the bind address of the MCP server. Defaults to 127.0.0.1. (#63)
 
 ### 🐛 Fixes

Cargo.lock

@@ -22,6 +22,18 @@ reqwest = { version = "0.12.15", default-features = false, features = [
 serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.140"
 thiserror = "2.0.12"
+tokio = { version = "1.45.0", features = [
+  "fs",
+  "io-std",
+  "macros",
+  "net",
+  "rt",
+  "rt-multi-thread",
+  "signal",
+  "sync",
+  "time",
+] }
+tokio-stream = "0.1"
 tracing = "0.1.41"
 tracing-core = "0.1.33"
 tracing-subscriber = { version = "0.3.19", features = ["json"] }

Cargo.toml

@@ -17,20 +17,13 @@ futures.workspace = true
 graphql_client = "0.14.0"
 insta.workspace = true
 notify = "8.0.0"
-parking_lot = "0.12"
 reqwest.workspace = true
 secrecy = "0.10.3"
 serde.workspace = true
 serde_json.workspace = true
 thiserror.workspace = true
-tokio = { version = "1.0", features = [
-  "fs",
-  "sync",
-  "time",
-  "rt-multi-thread",
-  "macros",
-] }
-tokio-stream = "0.1"
+tokio.workspace = true
+tokio-stream.workspace = true
 tower = "0.5.2"
 tracing.workspace = true
 url = "2.4"

crates/apollo-mcp-registry/Cargo.toml

@@ -28,14 +28,12 @@ const DEFAULT_WATCH_DURATION: Duration = Duration::from_millis(100);
 ///
 /// returns: impl Stream<Item=()>
 ///
-pub(crate) fn watch(path: &Path) -> impl Stream<Item = ()> + use<> {
+pub fn watch(path: &Path) -> impl Stream<Item = ()> + use<> {
     watch_with_duration(path, DEFAULT_WATCH_DURATION)
 }
 
 #[allow(clippy::panic)] // TODO: code copied from router contained existing panics
 fn watch_with_duration(path: &Path, duration: Duration) -> impl Stream<Item = ()> + use<> {
-    // Due to the vagaries of file watching across multiple platforms, instead of watching the
-    // supplied path (file), we are going to watch the parent (directory) of the path.
     let config_file_path = PathBuf::from(path);
     let watched_path = config_file_path.clone();
 
@@ -58,6 +56,8 @@ fn watch_with_duration(path: &Path, duration: Duration) -> impl Stream<Item = ()
                     event.kind,
                     EventKind::Modify(ModifyKind::Metadata(MetadataKind::WriteTime))
                         | EventKind::Modify(ModifyKind::Data(DataChange::Any))
+                        | EventKind::Create(_)
+                        | EventKind::Remove(_)
                 ) && event.paths.contains(&watched_path)
                 {
                     loop {

crates/apollo-mcp-registry/src/files.rs

@@ -1,3 +1,3 @@
-pub(crate) mod files;
+pub mod files;
 pub(crate) mod logging;
 pub mod uplink;

crates/apollo-mcp-registry/src/lib.rs

@@ -10,7 +10,6 @@ use tokio_stream::wrappers::ReceiverStream;
 use tower::BoxError;
 use url::Url;
 
-pub mod event;
 pub mod persisted_queries;
 pub mod schema;
 
@@ -136,7 +135,7 @@ impl Endpoints {
 }
 
 /// Configuration for polling Apollo Uplink.
-#[derive(Debug, Default)]
+#[derive(Clone, Debug, Default)]
 pub struct UplinkConfig {
     /// The Apollo key: `<YOUR_GRAPH_API_KEY>`
     pub apollo_key: SecretString,

crates/apollo-mcp-registry/src/uplink.rs

@@ -1,15 +1,14 @@
 use graphql_client::GraphQLQuery;
 
+pub mod event;
 mod manifest;
 mod manifest_poller;
 
 pub use manifest::FullPersistedQueryOperationId;
 pub use manifest::ManifestOperation;
 pub use manifest::PersistedQueryManifest;
 pub use manifest::SignedUrlChunk;
-pub use manifest_poller::ManifestChanged;
 pub use manifest_poller::ManifestSource;
-pub use manifest_poller::PersistedQueryManifestPoller;
 pub use manifest_poller::PersistedQueryManifestPollerState;
 
 use crate::uplink::UplinkRequest;

crates/apollo-mcp-registry/src/uplink/persisted_queries.rs

@@ -0,0 +1,18 @@
+use std::fmt::Debug;
+use std::fmt::Formatter;
+
+/// Persisted Query events
+pub enum Event {
+    /// The persisted query manifest was updated
+    UpdateManifest(Vec<(String, String)>),
+}
+
+impl Debug for Event {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Event::UpdateManifest(_) => {
+                write!(f, "UpdateManifest(<redacted>)")
+            }
+        }
+    }
+}