From 4715533743d8cd2e0660ebb6d9787cda1f323d68 Mon Sep 17 00:00:00 2001
From: Preetha Appan <preetha@hashicorp.com>
Date: Mon, 5 Mar 2018 16:56:36 -0600
Subject: [PATCH] Ignore left members when querying regions for leader in
 server-members command.

---
 command/server_members.go      |  6 ++++
 command/server_members_test.go | 60 ++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/command/server_members.go b/command/server_members.go
index 247378b71..55a31d268 100644
--- a/command/server_members.go
+++ b/command/server_members.go
@@ -168,6 +168,12 @@ func regionLeaders(client *api.Client, mem []*api.AgentMember) (map[string]strin
 	leaders := make(map[string]string)
 	regions := make(map[string]struct{})
 	for _, m := range mem {
+		// Ignore left members
+		// This prevents querying for leader status on regions where all members have left
+		if m.Status == "left" {
+			continue
+		}
+
 		regions[m.Tags["region"]] = struct{}{}
 	}
 
diff --git a/command/server_members_test.go b/command/server_members_test.go
index 7dd4e6232..e6ac296e6 100644
--- a/command/server_members_test.go
+++ b/command/server_members_test.go
@@ -1,9 +1,11 @@
 package command
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 
+	"github.com/hashicorp/nomad/command/agent"
 	"github.com/mitchellh/cli"
 )
 
@@ -66,3 +68,61 @@ func TestMembersCommand_Fails(t *testing.T) {
 		t.Fatalf("expected failed query error, got: %s", out)
 	}
 }
+
+// Tests that a single server region that left should still
+// not return an error and list other members in other regions
+func TestServerMembersCommand_MultiRegion_Leave(t *testing.T) {
+	t.Parallel()
+
+	config1 := func(c *agent.Config) {
+		c.Region = "r1"
+		c.Datacenter = "d1"
+	}
+
+	srv1, client1, url := testServer(t, false, config1)
+	defer srv1.Shutdown()
+
+	config2 := func(c *agent.Config) {
+		c.Region = "r2"
+		c.Datacenter = "d2"
+	}
+
+	srv2, _, _ := testServer(t, false, config2)
+	defer srv1.Shutdown()
+
+	// Join with srv1
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		srv1.Agent.Server().GetConfig().SerfConfig.MemberlistConfig.BindPort)
+
+	if _, err := srv2.Agent.Server().Join([]string{addr}); err != nil {
+		t.Fatalf("Join err: %v", err)
+	}
+	ui := new(cli.MockUi)
+	cmd := &ServerMembersCommand{Meta: Meta{Ui: ui}}
+
+	// Get our own node name
+	name, err := client1.Agent().NodeName()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Query the members
+	if code := cmd.Run([]string{"-address=" + url}); code != 0 {
+		t.Fatalf("expected exit 0, got: %d", code)
+	}
+	if out := ui.OutputWriter.String(); !strings.Contains(out, name) {
+		t.Fatalf("expected %q in output, got: %s", name, out)
+	}
+	ui.OutputWriter.Reset()
+
+	// Make one of the servers leave
+	srv2.Agent.Leave()
+
+	// Query again, should still contain expected output
+	if code := cmd.Run([]string{"-address=" + url}); code != 0 {
+		t.Fatalf("expected exit 0, got: %d", code)
+	}
+	if out := ui.OutputWriter.String(); !strings.Contains(out, name) {
+		t.Fatalf("expected %q in output, got: %s", name, out)
+	}
+}