add unauthenticated /health and /ready endpoints

2 files changed, 25 insertions, 1 deletions

diff --git a/src/api/health.rs b/src/api/health.rs
new file mode 100644
index 0000000..b1e4523
--- /dev/null
+++ b/src/api/health.rs
@@ -0,0 +1,20 @@
+//! `GET /health` and `GET /ready`: unauthenticated, for supervisors and load balancers.
+//! They say whether the node is up and whether it serves the store, nothing more.
+
+use axum::{extract::State, http::StatusCode};
+
+use crate::state::AppState;
+
+/// The HTTP API is up.
+pub(crate) async fn health() -> &'static str {
+    "ok\n"
+}
+
+/// The node serves reads and writes: ready, not joining or rejoining.
+pub(crate) async fn ready(State(state): State<AppState>) -> (StatusCode, &'static str) {
+    if state.is_ready().await {
+        (StatusCode::OK, "ready\n")
+    } else {
+        (StatusCode::SERVICE_UNAVAILABLE, "not ready\n")
+    }
+}
diff --git a/src/api/mod.rs b/src/api/mod.rs
index 296fa5e..bf7b06b 100644
--- a/src/api/mod.rs
+++ b/src/api/mod.rs
@@ -3,6 +3,7 @@
 pub(crate) mod auth;
 mod debug;
 mod document;
+mod health;
 mod log;
 mod peers;
 mod stats;
@@ -31,7 +32,8 @@ use crate::document::meta;
 use crate::document::store::StoreError;
 use crate::state::AppState;
 
-/// Builds the complete HTTP router. Everything except Swagger is authenticated.
+/// Builds the complete HTTP router. Everything except Swagger, `/health` and `/ready` is
+/// authenticated.
 pub(crate) fn router(state: AppState, auth_state: AuthState, debug_api: bool) -> Router {
     let mut api: Router<AppState> = Router::new()
         .route("/store", get(store::get_store_root))
@@ -64,6 +66,8 @@ pub(crate) fn router(state: AppState, auth_state: AuthState, debug_api: bool) ->
 
     api.layer(middleware::from_fn_with_state(auth_state, basic_auth))
         .merge(SwaggerUi::new("/swagger-ui").url("/openapi.json", ApiDoc::openapi()))
+        .route("/health", get(health::health))
+        .route("/ready", get(health::ready))
         // Outermost, so authentication failures get the error body too.
         .layer(middleware::from_fn(json_errors))
         .with_state(state)