testing: disable global metrics sink in tests

This might be better handled by allowing configuration for the InMemSink interval and retail, and disabling
the global. For now this is a smaller change to remove the goroutine leak caused by tests because go-metrics
does not provide any way of shutting down the global goroutine.

agent/acl_test.go

@@ -42,12 +42,16 @@ func NewTestACLAgent(t *testing.T, name string, hcl string, resolveAuthz authzRe
 	dataDir := testutil.TempDir(t, "acl-agent")
 
 	logBuffer := testutil.NewLogBuffer(t)
-	loader := func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error) {
+	loader := func(source config.Source) (*config.RuntimeConfig, []string, error) {
 		dataDir := fmt.Sprintf(`data_dir = "%s"`, dataDir)
 		opts := config.BuilderOpts{
 			HCL: []string{TestConfigHCL(NodeID()), hcl, dataDir},
 		}
-		return config.Load(opts, source)
+		cfg, warnings, err := config.Load(opts, source)
+		if cfg != nil {
+			cfg.Telemetry.Disable = true
+		}
+		return cfg, warnings, err
 	}
 	bd, err := NewBaseDeps(loader, logBuffer)
 	require.NoError(t, err)
@@ -58,7 +62,7 @@ func NewTestACLAgent(t *testing.T, name string, hcl string, resolveAuthz authzRe
 		Output:     logBuffer,
 		TimeFormat: "04:05.000",
 	})
-	bd.TelemetrySink = metrics.NewInmemSink(1*time.Second, time.Minute)
+	bd.MetricsHandler = metrics.NewInmemSink(1*time.Second, time.Minute)
 
 	agent, err := New(bd)
 	require.NoError(t, err)

agent/agent.go

@@ -171,7 +171,7 @@ type Agent struct {
 	logger hclog.InterceptLogger
 
 	// In-memory sink used for collecting metrics
-	MemSink *metrics.InmemSink
+	MemSink MetricsHandler
 
 	// delegate is either a *consul.Server or *consul.Client
 	// depending on the configuration
@@ -349,7 +349,7 @@ func New(bd BaseDeps) (*Agent, error) {
 		tlsConfigurator: bd.TLSConfigurator,
 		config:          bd.RuntimeConfig,
 		cache:           bd.Cache,
-		MemSink:         bd.TelemetrySink,
+		MemSink:         bd.MetricsHandler,
 		connPool:        bd.ConnPool,
 		autoConf:        bd.AutoConfig,
 	}

agent/config/runtime_test.go

@@ -7100,6 +7100,7 @@ func TestSanitize(t *testing.T) {
 			"CirconusCheckTags": "",
 			"CirconusSubmissionInterval": "",
 			"CirconusSubmissionURL": "",
+			"Disable": false,
 			"DisableHostname": false,
 			"DogstatsdAddr": "",
 			"DogstatsdTags": [],

agent/setup.go

@@ -5,9 +5,9 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"net/http"
 	"time"
 
-	"github.com/armon/go-metrics"
 	autoconf "github.com/hashicorp/consul/agent/auto-config"
 	"github.com/hashicorp/consul/agent/cache"
 	certmon "github.com/hashicorp/consul/agent/cert-monitor"
@@ -28,7 +28,7 @@ import (
 type BaseDeps struct {
 	Logger          hclog.InterceptLogger
 	TLSConfigurator *tlsutil.Configurator // TODO: use an interface
-	TelemetrySink   *metrics.InmemSink    // TODO: use an interface
+	MetricsHandler  MetricsHandler
 	RuntimeConfig   *config.RuntimeConfig
 	Tokens          *token.Store
 	Cache           *cache.Cache
@@ -36,6 +36,11 @@ type BaseDeps struct {
 	ConnPool        *pool.ConnPool       // TODO: use an interface
 }
 
+// MetricsHandler provides an http.Handler for displaying metrics.
+type MetricsHandler interface {
+	DisplayMetrics(resp http.ResponseWriter, req *http.Request) (interface{}, error)
+}
+
 type ConfigLoader func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error)
 
 func NewBaseDeps(configLoader ConfigLoader, logOut io.Writer) (BaseDeps, error) {
@@ -71,7 +76,7 @@ func NewBaseDeps(configLoader ConfigLoader, logOut io.Writer) (BaseDeps, error)
 		return d, fmt.Errorf("failed to setup node ID: %w", err)
 	}
 
-	d.TelemetrySink, err = lib.InitTelemetry(cfg.Telemetry)
+	d.MetricsHandler, err = lib.InitTelemetry(cfg.Telemetry)
 	if err != nil {
 		return d, fmt.Errorf("failed to initialize telemetry: %w", err)
 	}

agent/testagent.go

@@ -170,7 +170,7 @@ func (a *TestAgent) Start(t *testing.T) (err error) {
 
 	// Create NodeID outside the closure, so that it does not change
 	testHCLConfig := TestConfigHCL(NodeID())
-	loader := func(source config.Source) (cfg *config.RuntimeConfig, warnings []string, err error) {
+	loader := func(source config.Source) (*config.RuntimeConfig, []string, error) {
 		opts := config.BuilderOpts{
 			HCL: []string{testHCLConfig, portsConfig, a.HCL, hclDataDir},
 		}
@@ -182,13 +182,17 @@ func (a *TestAgent) Start(t *testing.T) (err error) {
 			config.DefaultConsulSource(),
 			config.DevConsulSource(),
 		}
-		return config.Load(opts, source, overrides...)
+		cfg, warnings, err := config.Load(opts, source, overrides...)
+		if cfg != nil {
+			cfg.Telemetry.Disable = true
+		}
+		return cfg, warnings, err
 	}
 	bd, err := NewBaseDeps(loader, logOutput)
 	require.NoError(t, err)
 
 	bd.Logger = logger
-	bd.TelemetrySink = metrics.NewInmemSink(1*time.Second, time.Minute)
+	bd.MetricsHandler = metrics.NewInmemSink(1*time.Second, time.Minute)
 	a.Config = bd.RuntimeConfig
 
 	agent, err := New(bd)

lib/telemetry.go

@@ -19,6 +19,10 @@ import (
 // the shared InitTelemetry functions below, but we can't import agent/config
 // due to a dependency cycle.
 type TelemetryConfig struct {
+	// Disable may be set to true to have InitTelemetry to skip initialization
+	// and return a nil MetricsSink.
+	Disable bool
+
 	// Circonus*: see https://github.com/circonus-labs/circonus-gometrics
 	// for more details on the various configuration options.
 	// Valid configuration combinations:
@@ -326,6 +330,9 @@ func circonusSink(cfg TelemetryConfig, hostname string) (metrics.MetricSink, err
 // InitTelemetry configures go-metrics based on map of telemetry config
 // values as returned by Runtimecfg.Config().
 func InitTelemetry(cfg TelemetryConfig) (*metrics.InmemSink, error) {
+	if cfg.Disable {
+		return nil, nil
+	}
 	// Setup telemetry
 	// Aggregate on 10 second intervals for 1 minute. Expose the
 	// metrics over stderr when there is a SIGUSR1 received.