From 6aae0bd4849bc5faf04a194d89f19a38dc451b75 Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Fri, 18 Sep 2020 15:48:18 +1000
Subject: [PATCH] Tidy cors header

---
 Cargo.lock                          |  1 +
 beacon_node/http_api/src/lib.rs     | 14 +-------------
 beacon_node/http_metrics/Cargo.toml |  1 +
 beacon_node/http_metrics/src/lib.rs | 14 +-------------
 common/warp_utils/src/lib.rs        |  1 +
 common/warp_utils/src/reply.rs      | 15 +++++++++++++++
 6 files changed, 20 insertions(+), 26 deletions(-)
 create mode 100644 common/warp_utils/src/reply.rs

diff --git a/Cargo.lock b/Cargo.lock
index d763a62d58f..9821d14d93c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2348,6 +2348,7 @@ dependencies = [
  "tokio 0.2.22",
  "types",
  "warp",
+ "warp_utils",
 ]
 
 [[package]]
diff --git a/beacon_node/http_api/src/lib.rs b/beacon_node/http_api/src/lib.rs
index 5392a81a883..8bc5236dd65 100644
--- a/beacon_node/http_api/src/lib.rs
+++ b/beacon_node/http_api/src/lib.rs
@@ -1584,19 +1584,7 @@ pub fn serve<T: BeaconChainTypes>(
         .with(slog_logging(log.clone()))
         .with(prometheus_metrics())
         .map(|reply| warp::reply::with_header(reply, "Server", &version_with_platform()))
-        .map(move |reply| {
-            let reply: Box<dyn warp::Reply> = if let Some(allow_origin) = allow_origin.as_ref() {
-                Box::new(warp::reply::with_header(
-                    reply,
-                    "Access-Control-Allow-Origin",
-                    allow_origin,
-                ))
-            } else {
-                Box::new(reply)
-            };
-
-            reply
-        });
+        .map(move |reply| warp_utils::reply::maybe_cors(reply, allow_origin.as_ref()));
 
     let (listening_socket, server) = warp::serve(routes).try_bind_with_graceful_shutdown(
         SocketAddrV4::new(config.listen_addr, config.listen_port),
diff --git a/beacon_node/http_metrics/Cargo.toml b/beacon_node/http_metrics/Cargo.toml
index fd2f7975fb1..482f7a5debc 100644
--- a/beacon_node/http_metrics/Cargo.toml
+++ b/beacon_node/http_metrics/Cargo.toml
@@ -19,6 +19,7 @@ lighthouse_metrics = { path = "../../common/lighthouse_metrics" }
 lazy_static = "1.4.0"
 eth2 = { path = "../../common/eth2" }
 lighthouse_version = { path = "../../common/lighthouse_version" }
+warp_utils = { path = "../../common/warp_utils" }
 
 [dev-dependencies]
 tokio = { version = "0.2.21", features = ["sync"] }
diff --git a/beacon_node/http_metrics/src/lib.rs b/beacon_node/http_metrics/src/lib.rs
index eb846a99472..053ecaa501b 100644
--- a/beacon_node/http_metrics/src/lib.rs
+++ b/beacon_node/http_metrics/src/lib.rs
@@ -90,19 +90,7 @@ pub fn serve<T: BeaconChainTypes>(
             )
         })
         .map(|reply| warp::reply::with_header(reply, "Server", &version_with_platform()))
-        .map(move |reply| {
-            let reply: Box<dyn warp::Reply> = if let Some(allow_origin) = allow_origin.as_ref() {
-                Box::new(warp::reply::with_header(
-                    reply,
-                    "Access-Control-Allow-Origin",
-                    allow_origin,
-                ))
-            } else {
-                Box::new(reply)
-            };
-
-            reply
-        });
+        .map(move |reply| warp_utils::reply::maybe_cors(reply, allow_origin.as_ref()));
 
     let (listening_socket, server) = warp::serve(routes).try_bind_with_graceful_shutdown(
         SocketAddrV4::new(config.listen_addr, config.listen_port),
diff --git a/common/warp_utils/src/lib.rs b/common/warp_utils/src/lib.rs
index e181278ba37..22ada7426aa 100644
--- a/common/warp_utils/src/lib.rs
+++ b/common/warp_utils/src/lib.rs
@@ -1 +1,2 @@
 pub mod reject;
+pub mod reply;
diff --git a/common/warp_utils/src/reply.rs b/common/warp_utils/src/reply.rs
new file mode 100644
index 00000000000..dcec6214f0c
--- /dev/null
+++ b/common/warp_utils/src/reply.rs
@@ -0,0 +1,15 @@
+/// Add CORS headers to `reply` only if `allow_origin.is_some()`.
+pub fn maybe_cors<T: warp::Reply + 'static>(
+    reply: T,
+    allow_origin: Option<&String>,
+) -> Box<dyn warp::Reply> {
+    if let Some(allow_origin) = allow_origin {
+        Box::new(warp::reply::with_header(
+            reply,
+            "Access-Control-Allow-Origin",
+            allow_origin,
+        ))
+    } else {
+        Box::new(reply)
+    }
+}