Address PR feedback

agent/consul/server.go

@@ -569,15 +569,15 @@ func NewServer(config *Config, flat Deps) (*Server, error) {
 			WithStateProvider(s.fsm).
 			WithLogger(s.logger).
 			WithDatacenter(s.config.Datacenter).
-			WithReportingInterval(s.config.MetricsReportingInterval),
-		func() []serf.Member {
-			members, err := s.LANMembersAllSegments()
-			if err != nil {
-				return []serf.Member{}
-			}
+			WithReportingInterval(s.config.MetricsReportingInterval).
+			WithGetMembersFunc(func() []serf.Member {
+				members, err := s.LANMembersAllSegments()
+				if err != nil {
+					return []serf.Member{}
+				}
 
-			return members
-		},
+				return members
+			}),
 	)
 	if err != nil {
 		s.Shutdown()

agent/consul/usagemetrics/usagemetrics.go

@@ -37,13 +37,16 @@ var Gauges = []prometheus.GaugeDefinition{
 	},
 }
 
+type getMembersFunc func() []serf.Member
+
 // Config holds the settings for various parameters for the
 // UsageMetricsReporter
 type Config struct {
 	logger         hclog.Logger
 	metricLabels   []metrics.Label
 	stateProvider  StateProvider
 	tickerInterval time.Duration
+	getMembersFunc getMembersFunc
 }
 
 // WithDatacenter adds the datacenter as a label to all metrics emitted by the
@@ -72,14 +75,18 @@ func (c *Config) WithStateProvider(sp StateProvider) *Config {
 	return c
 }
 
+// WithGetMembersFunc specifies the function used to identify cluster members
+func (c *Config) WithGetMembersFunc(fn getMembersFunc) *Config {
+	c.getMembersFunc = fn
+	return c
+}
+
 // StateProvider defines an inteface for retrieving a state.Store handle. In
 // non-test code, this is satisfied by the fsm.FSM struct.
 type StateProvider interface {
 	State() *state.Store
 }
 
-type getMembersFunc func() []serf.Member
-
 // UsageMetricsReporter provides functionality for emitting usage metrics into
 // the metrics stream. This makes it essentially a translation layer
 // between the state store and metrics stream.
@@ -91,11 +98,15 @@ type UsageMetricsReporter struct {
 	getMembersFunc getMembersFunc
 }
 
-func NewUsageMetricsReporter(cfg *Config, getMembersFunc getMembersFunc) (*UsageMetricsReporter, error) {
+func NewUsageMetricsReporter(cfg *Config) (*UsageMetricsReporter, error) {
 	if cfg.stateProvider == nil {
 		return nil, errors.New("must provide a StateProvider to usage reporter")
 	}
 
+	if cfg.getMembersFunc == nil {
+		return nil, errors.New("must provide a getMembersFunc to usage reporter")
+	}
+
 	if cfg.logger == nil {
 		cfg.logger = hclog.NewNullLogger()
 	}
@@ -110,7 +121,7 @@ func NewUsageMetricsReporter(cfg *Config, getMembersFunc getMembersFunc) (*Usage
 		stateProvider:  cfg.stateProvider,
 		metricLabels:   cfg.metricLabels,
 		tickerInterval: cfg.tickerInterval,
-		getMembersFunc: getMembersFunc,
+		getMembersFunc: cfg.getMembersFunc,
 	}
 
 	return u, nil

agent/consul/usagemetrics/usagemetrics_oss_test.go

@@ -62,6 +62,7 @@ func TestUsageReporter_emitServiceUsage_OSS(t *testing.T) {
 					},
 				},
 			},
+			getMembersFunc: func() []serf.Member { return []serf.Member{} },
 		},
 		"nodes-and-services": {
 			modfiyStateStore: func(t *testing.T, s *state.Store) {
@@ -159,8 +160,8 @@ func TestUsageReporter_emitServiceUsage_OSS(t *testing.T) {
 				new(Config).
 					WithStateProvider(mockStateProvider).
 					WithLogger(testutil.Logger(t)).
-					WithDatacenter("dc1"),
-				tcase.getMembersFunc,
+					WithDatacenter("dc1").
+					WithGetMembersFunc(tcase.getMembersFunc),
 			)
 			require.NoError(t, err)
 

agent/consul/usagemetrics/usagemetrics_test.go

@@ -38,6 +38,7 @@ func TestUsageReporter_Run_Nodes(t *testing.T) {
 					Labels: []metrics.Label{{Name: "datacenter", Value: "dc1"}},
 				},
 			},
+			getMembersFunc: func() []serf.Member { return []serf.Member{} },
 		},
 		"nodes": {
 			modfiyStateStore: func(t *testing.T, s *state.Store) {
@@ -104,8 +105,8 @@ func TestUsageReporter_Run_Nodes(t *testing.T) {
 				new(Config).
 					WithStateProvider(mockStateProvider).
 					WithLogger(testutil.Logger(t)).
-					WithDatacenter("dc1"),
-				tcase.getMembersFunc,
+					WithDatacenter("dc1").
+					WithGetMembersFunc(tcase.getMembersFunc),
 			)
 			require.NoError(t, err)