From ed4d7aa44a03d32cceaabc26c1e4017a6da4987e Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Mon, 27 May 2019 17:09:16 +1000
Subject: [PATCH] Replace `http_server` unwrap with 500 error

---
 beacon_node/http_server/src/api.rs     | 7 ++++---
 beacon_node/http_server/src/lib.rs     | 8 ++++++++
 beacon_node/http_server/src/metrics.rs | 6 ++++--
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/beacon_node/http_server/src/api.rs b/beacon_node/http_server/src/api.rs
index 11afdb9df3..a910808998 100644
--- a/beacon_node/http_server/src/api.rs
+++ b/beacon_node/http_server/src/api.rs
@@ -1,4 +1,4 @@
-use crate::key::BeaconChainKey;
+use crate::{key::BeaconChainKey, map_persistent_err_to_500};
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use iron::prelude::*;
 use iron::{
@@ -58,8 +58,9 @@ impl AfterMiddleware for SetJsonContentType {
 }
 
 fn handle_fork<T: BeaconChainTypes + 'static>(req: &mut Request) -> IronResult<Response> {
-    // TODO: investigate unwrap - I'm _guessing_ we'll never hit it but we should check to be sure.
-    let beacon_chain = req.get::<Read<BeaconChainKey<T>>>().unwrap();
+    let beacon_chain = req
+        .get::<Read<BeaconChainKey<T>>>()
+        .map_err(map_persistent_err_to_500)?;
 
     let response = json!({
         "fork": beacon_chain.head().beacon_state.fork,
diff --git a/beacon_node/http_server/src/lib.rs b/beacon_node/http_server/src/lib.rs
index 77665db8dd..486badaff2 100644
--- a/beacon_node/http_server/src/lib.rs
+++ b/beacon_node/http_server/src/lib.rs
@@ -108,3 +108,11 @@ pub fn start_service<T: BeaconChainTypes + 'static>(
 
     shutdown_trigger
 }
+
+/// Helper function for mapping a failure to read state to a 500 server error.
+fn map_persistent_err_to_500(e: persistent::PersistentError) -> iron::error::IronError {
+    iron::error::IronError {
+        error: Box::new(e),
+        response: iron::Response::with(iron::status::Status::InternalServerError),
+    }
+}
diff --git a/beacon_node/http_server/src/metrics.rs b/beacon_node/http_server/src/metrics.rs
index 30acb88531..eb7816d0eb 100644
--- a/beacon_node/http_server/src/metrics.rs
+++ b/beacon_node/http_server/src/metrics.rs
@@ -1,4 +1,4 @@
-use crate::key::BeaconChainKey;
+use crate::{key::BeaconChainKey, map_persistent_err_to_500};
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use iron::prelude::*;
 use iron::{status::Status, Handler, IronResult, Request, Response};
@@ -23,7 +23,9 @@ pub fn build_handler<T: BeaconChainTypes + 'static>(
 ///
 /// Returns a text string containing all metrics.
 fn handle_metrics<T: BeaconChainTypes + 'static>(req: &mut Request) -> IronResult<Response> {
-    let beacon_chain = req.get::<Read<BeaconChainKey<T>>>().unwrap();
+    let beacon_chain = req
+        .get::<Read<BeaconChainKey<T>>>()
+        .map_err(map_persistent_err_to_500)?;
 
     let r = Registry::new();