Add healthcheck route at /__miniserve_internal/healthcheck

Fixes #1435

4 files changed, 38 insertions, 7 deletions

diff --git a/README.md b/README.md
index b3b5e44..d211065 100644
--- a/README.md
+++ b/README.md
@@ -143,6 +143,7 @@ Some mobile browsers like Firefox on Android will offer to open the camera app w
 - Supports README.md rendering like on GitHub
 - Range requests
 - WebDAV support
+- Healthcheck route (at `/__miniserve_internal/healthcheck`)
 
 ## Usage
 
diff --git a/src/config.rs b/src/config.rs
index 379f7a7..7d491c4 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -63,10 +63,13 @@ pub struct MiniserveConfig {
     /// Route prefix; Either empty or prefixed with slash
     pub route_prefix: String,
 
-    /// Randomly generated favicon route
+    /// Well-known healthcheck route (prefixed if route_prefix is provided)
+    pub healthcheck_route: String,
+
+    /// Well-known favicon route (prefixed if route_prefix is provided)
     pub favicon_route: String,
 
-    /// Randomly generated css route
+    /// Well-known css route (prefixed if route_prefix is provided)
     pub css_route: String,
 
     /// Default color scheme
@@ -198,19 +201,21 @@ impl MiniserveConfig {
             }
         }
 
-        // Generate some random routes for the favicon and css so that they are very unlikely to conflict with
-        // real files.
-        // If --random-route is enabled , in order to not leak the random generated route, we must not use it
+        // Format some well-known routes at paths that are very unlikely to conflict with real
+        // files.
+        // If --random-route is enabled, in order to not leak the random generated route, we must not use it
         // as static files prefix.
         // Otherwise, we should apply route_prefix to static files.
-        let (favicon_route, css_route) = if args.random_route {
+        let (healthcheck_route, favicon_route, css_route) = if args.random_route {
             (
+                "/__miniserve_internal/healthcheck".into(),
                 "/__miniserve_internal/favicon.svg".into(),
                 "/__miniserve_internal/style.css".into(),
             )
         } else {
             (
-                format!("{}/{}", route_prefix, "__miniserve_internal/favicon.ico"),
+                format!("{}/{}", route_prefix, "__miniserve_internal/healthcheck"),
+                format!("{}/{}", route_prefix, "__miniserve_internal/favicon.svg"),
                 format!("{}/{}", route_prefix, "__miniserve_internal/style.css"),
             )
         };
@@ -299,6 +304,7 @@ impl MiniserveConfig {
             default_sorting_method: args.default_sorting_method,
             default_sorting_order: args.default_sorting_order,
             route_prefix,
+            healthcheck_route,
             favicon_route,
             css_route,
             default_color_scheme,
diff --git a/src/main.rs b/src/main.rs
index ccf611c..688aed1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -219,6 +219,7 @@ async fn run(miniserve_config: MiniserveConfig) -> Result<(), StartupError> {
                 miniserve_config.compress_response,
                 middleware::Compress::default(),
             ))
+            .route(&inside_config.healthcheck_route, web::get().to(healthcheck))
             .route(&inside_config.favicon_route, web::get().to(favicon))
             .route(&inside_config.css_route, web::get().to(css))
             .service(
@@ -429,6 +430,10 @@ async fn error_404(req: HttpRequest) -> Result<HttpResponse, RuntimeError> {
     Err(RuntimeError::RouteNotFoundError(req.path().to_string()))
 }
 
+async fn healthcheck() -> impl Responder {
+    HttpResponse::Ok().body("OK")
+}
+
 async fn favicon() -> impl Responder {
     let logo = include_str!("../data/logo.svg");
     HttpResponse::Ok()
diff --git a/tests/serve_request.rs b/tests/serve_request.rs
index f840efd..2910074 100644
--- a/tests/serve_request.rs
+++ b/tests/serve_request.rs
@@ -73,6 +73,25 @@ fn serves_requests_with_non_default_port(server: TestServer) -> Result<(), Error
 }
 
 #[rstest]
+#[case("__miniserve_internal/healthcheck", server(None::<&str>))]
+#[case("__miniserve_internal/favicon.svg", server(None::<&str>))]
+#[case("__miniserve_internal/style.css", server(None::<&str>))]
+#[case("testlol/__miniserve_internal/healthcheck", server(&["--route-prefix", "testlol"]))]
+#[case("testlol/__miniserve_internal/favicon.svg", server(&["--route-prefix", "testlol"]))]
+#[case("testlol/__miniserve_internal/style.css", server(&["--route-prefix", "testlol"]))]
+#[case("__miniserve_internal/healthcheck", server(&["--random-route"]))]
+#[case("__miniserve_internal/favicon.svg", server(&["--random-route"]))]
+#[case("__miniserve_internal/style.css", server(&["--random-route"]))]
+fn serves_requests_for_special_routes(
+    #[case] route: &str,
+    #[case] server: TestServer,
+) -> Result<(), Error> {
+    let body = reqwest::blocking::get(format!("{}{}", server.url(), route))?.error_for_status()?;
+
+    Ok(())
+}
+
+#[rstest]
 fn serves_requests_hidden_files(#[with(&["--hidden"])] server: TestServer) -> Result<(), Error> {
     let body = reqwest::blocking::get(server.url())?.error_for_status()?;
     let parsed = Document::from_read(body)?;