From 32faaaf4180be9438b87548d6314499256d35e3a Mon Sep 17 00:00:00 2001
From: Henrik Hautakoski <henrik@eossweden.org>
Date: Wed, 24 Jun 2020 14:38:46 +0200
Subject: [PATCH 1/2] Adding src/utils/json.go

---
 src/utils/json.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 src/utils/json.go

diff --git a/src/utils/json.go b/src/utils/json.go
new file mode 100644
index 0000000..17feeba
--- /dev/null
+++ b/src/utils/json.go
@@ -0,0 +1,17 @@
+
+package utils
+
+//  JsonGetInt64
+//    performs float64 (json numbers are always float64)
+//    type assertion and casts to int64.
+//
+//    if the type assertion fails, the function defaults 0 (zero).
+// ---------------------------------------------------------
+
+func JsonGetInt64(input interface{}) (int64) {
+	v, res := input.(float64)
+	if res {
+		return (int64) (v)
+	}
+	return 0
+}

From ba6b79ae0ecc8efd749f9f111bc7e483afd8a8ab Mon Sep 17 00:00:00 2001
From: Henrik Hautakoski <henrik@eossweden.org>
Date: Wed, 24 Jun 2020 14:41:13 +0200
Subject: [PATCH 2/2] src/server.go: in check_api_v2() use utils.JsonGetInt64()
 to safely get a int64 value from json.

If json contains "nil" value, the type assertion will fail. JsonGetInt64() will in that case return "0"
---
 src/server.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/server.go b/src/server.go
index 595efcc..c46c799 100644
--- a/src/server.go
+++ b/src/server.go
@@ -9,6 +9,7 @@ import (
 	"./pid"
 	"./haproxy"
 	"./eosapi"
+	"./utils"
     "github.com/firstrow/tcp_server"
 	"github.com/pborman/getopt/v2"
 )
@@ -55,9 +56,9 @@ func check_api_v2(p eosapi.ReqParams, offset int64) (haproxy.HealthCheckStatus,
 
 	for _, v := range health.Health {
 		if v.Name == "Elasticsearch" {
-			es_block = (int64) (v.Data["last_indexed_block"].(float64))
+			es_block = utils.JsonGetInt64(v.Data["last_indexed_block"])
 		} else if v.Name == "NodeosRPC" {
-			node_block = (int64) (v.Data["head_block_num"].(float64))
+			node_block = utils.JsonGetInt64(v.Data["head_block_num"])
 		}
 	}