From e02f10311c6e47d051bc4824d8ea783607fc0895 Mon Sep 17 00:00:00 2001
From: Nic Jackson <jackson.nic@gmail.com>
Date: Thu, 30 Jul 2020 11:26:15 +0100
Subject: [PATCH] Modify Status Leader API to return Status 500 when there is
 no leader

---
 .changelog/8408.txt           |  4 ++++
 agent/status_endpoint.go      |  6 ++++++
 agent/status_endpoint_test.go | 13 +++++++++++++
 3 files changed, 23 insertions(+)
 create mode 100644 .changelog/8408.txt

diff --git a/.changelog/8408.txt b/.changelog/8408.txt
new file mode 100644
index 000000000000..396e3ec5a89b
--- /dev/null
+++ b/.changelog/8408.txt
@@ -0,0 +1,4 @@
+```release-note:bug
+api: when the cluster has no leader return an error from `/v1/status/leader` to be consistent with all other endpoints.
+```
+
diff --git a/agent/status_endpoint.go b/agent/status_endpoint.go
index 5cc329ac9e3a..76851971f87c 100644
--- a/agent/status_endpoint.go
+++ b/agent/status_endpoint.go
@@ -16,6 +16,12 @@ func (s *HTTPHandlers) StatusLeader(resp http.ResponseWriter, req *http.Request)
 	if err := s.agent.RPC("Status.Leader", &args, &out); err != nil {
 		return nil, err
 	}
+
+	// check there is a leader, if not return a status no content
+	if out == "" {
+		return nil, structs.ErrNoLeader
+	}
+
 	return out, nil
 }
 
diff --git a/agent/status_endpoint_test.go b/agent/status_endpoint_test.go
index 93768618c322..f0b6dddadda1 100644
--- a/agent/status_endpoint_test.go
+++ b/agent/status_endpoint_test.go
@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"testing"
 
+	"github.com/hashicorp/consul/agent/structs"
 	"github.com/hashicorp/consul/sdk/testutil/retry"
 	"github.com/hashicorp/consul/testrpc"
 	"github.com/stretchr/testify/require"
@@ -31,6 +32,18 @@ func TestStatusLeader(t *testing.T) {
 	}
 }
 
+func TestStatusLeaderNoLeaderReturnsStatus500(t *testing.T) {
+	t.Parallel()
+	a := NewTestAgent(t, "bootstrap_expect=2 bootstrap=false")
+	defer a.Shutdown()
+
+	req, _ := http.NewRequest("GET", "/v1/status/leader", nil)
+	_, err := a.srv.StatusLeader(nil, req)
+
+	require.Error(t, err)
+	require.Equal(t, structs.ErrNoLeader, err)
+}
+
 func TestStatusLeaderSecondary(t *testing.T) {
 	if testing.Short() {
 		t.Skip("too slow for testing.Short")