From a9593bad66fe0c0983b71378d6028c92b05af62c Mon Sep 17 00:00:00 2001
From: Blair McMillan <blair@mcmillan.id.au>
Date: Mon, 3 Dec 2018 14:59:31 +1000
Subject: [PATCH] Prevent read/write map concurrency issue

---
 registry/consul_registry.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/registry/consul_registry.go b/registry/consul_registry.go
index 52ccf759..02725b5d 100644
--- a/registry/consul_registry.go
+++ b/registry/consul_registry.go
@@ -190,16 +190,17 @@ func (c *consulRegistry) Register(s *Service, opts ...RegisterOption) error {
 	// use first node
 	node := s.Nodes[0]
 
-	// get existing hash
+	// get existing hash and last checked time
 	c.Lock()
 	v, ok := c.register[s.Name]
+	lastChecked := c.lastChecked[s.Name]
 	c.Unlock()
 
 	// if it's already registered and matches then just pass the check
 	if ok && v == h {
 		if options.TTL == time.Duration(0) {
 			// ensure that our service hasn't been deregistered by Consul
-			if time.Since(c.lastChecked[s.Name]) <= getDeregisterTTL(regInterval) {
+			if time.Since(lastChecked) <= getDeregisterTTL(regInterval) {
 				return nil
 			}
 			services, _, err := c.Client.Health().Checks(s.Name, c.queryOptions)