push prometheus sink definiitons into prometheus.PrometheusOpts

agent/agent_endpoint.go

@@ -136,7 +136,7 @@ func (s *HTTPHandlers) AgentMetrics(resp http.ResponseWriter, req *http.Request)
 		return nil, acl.ErrPermissionDenied
 	}
 	if enablePrometheusOutput(req) {
-		if s.agent.config.Telemetry.PrometheusRetentionTime < 1 {
+		if s.agent.config.Telemetry.PrometheusOpts.Expiration < 1 {
 			resp.WriteHeader(http.StatusUnsupportedMediaType)
 			fmt.Fprint(resp, "Prometheus is not enabled since its retention time is not positive")
 			return nil, nil

agent/config/builder.go

@@ -17,6 +17,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/armon/go-metrics/prometheus"
 	"github.com/hashicorp/go-bexpr"
 	"github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/go-multierror"
@@ -942,13 +943,15 @@ func (b *Builder) Build() (rt RuntimeConfig, err error) {
 			DisableHostname:                    b.boolVal(c.Telemetry.DisableHostname),
 			DogstatsdAddr:                      b.stringVal(c.Telemetry.DogstatsdAddr),
 			DogstatsdTags:                      c.Telemetry.DogstatsdTags,
-			PrometheusRetentionTime:            b.durationVal("prometheus_retention_time", c.Telemetry.PrometheusRetentionTime),
 			FilterDefault:                      b.boolVal(c.Telemetry.FilterDefault),
 			AllowedPrefixes:                    telemetryAllowedPrefixes,
 			BlockedPrefixes:                    telemetryBlockedPrefixes,
 			MetricsPrefix:                      b.stringVal(c.Telemetry.MetricsPrefix),
 			StatsdAddr:                         b.stringVal(c.Telemetry.StatsdAddr),
 			StatsiteAddr:                       b.stringVal(c.Telemetry.StatsiteAddr),
+			PrometheusOpts: prometheus.PrometheusOpts{
+				Expiration: b.durationVal("prometheus_retention_time", c.Telemetry.PrometheusRetentionTime),
+			},
 		},
 
 		// Agent

agent/setup.go

@@ -78,7 +78,11 @@ func NewBaseDeps(configLoader ConfigLoader, logOut io.Writer) (BaseDeps, error)
 		return d, fmt.Errorf("failed to setup node ID: %w", err)
 	}
 
-	d.MetricsHandler, err = lib.InitTelemetry(cfg.Telemetry, getPrometheusDefs())
+	gauges, counters, summaries := getPrometheusDefs()
+	cfg.Telemetry.PrometheusOpts.GaugeDefinitions = gauges
+	cfg.Telemetry.PrometheusOpts.CounterDefinitions = counters
+	cfg.Telemetry.PrometheusOpts.SummaryDefinitions = summaries
+	d.MetricsHandler, err = lib.InitTelemetry(cfg.Telemetry)
 	if err != nil {
 		return d, fmt.Errorf("failed to initialize telemetry: %w", err)
 	}
@@ -186,7 +190,7 @@ func registerWithGRPC(b grpcresolver.Builder) {
 
 // getPrometheusDefs reaches into every slice of prometheus defs we've defined in each part of the agent, and appends
 //  all of our slices into one nice slice of definitions per metric type for the Consul agent to pass to go-metrics.
-func getPrometheusDefs() lib.PrometheusDefs {
+func getPrometheusDefs() ([]prometheus.GaugeDefinition, []prometheus.CounterDefinition, []prometheus.SummaryDefinition) {
 	serviceName := []string{"consul"}
 	var gauges = [][]prometheus.GaugeDefinition{
 		cache.Gauges,
@@ -290,9 +294,5 @@ func getPrometheusDefs() lib.PrometheusDefs {
 		summaryDefs = append(summaryDefs, withService...)
 	}
 
-	return lib.PrometheusDefs{
-		Gauges:    gaugeDefs,
-		Counters:  counterDefs,
-		Summaries: summaryDefs,
-	}
+	return gaugeDefs, counterDefs, summaryDefs
 }

connect/proxy/proxy.go

@@ -56,7 +56,7 @@ func (p *Proxy) Serve() error {
 				// Setup telemetry if configured
 				// NOTE(kit): As far as I can tell, all of the metrics in the proxy are generated at runtime, so we
 				//  don't have any static metrics we initialize at start.
-				_, err := lib.InitTelemetry(newCfg.Telemetry, lib.EmptyPrometheusDefs())
+				_, err := lib.InitTelemetry(newCfg.Telemetry)
 				if err != nil {
 					p.logger.Error("proxy telemetry config error", "error", err)
 				}

lib/telemetry.go

@@ -154,14 +154,6 @@ type TelemetryConfig struct {
 	// hcl: telemetry { dogstatsd_tags = []string }
 	DogstatsdTags []string `json:"dogstatsd_tags,omitempty" mapstructure:"dogstatsd_tags"`
 
-	// PrometheusRetentionTime is the retention time for prometheus metrics if greater than 0.
-	// A value of 0 disable Prometheus support. Regarding Prometheus, it is considered a good
-	// practice to put large values here (such as a few days), and at least the interval between
-	// prometheus requests.
-	//
-	// hcl: telemetry { prometheus_retention_time = "duration" }
-	PrometheusRetentionTime time.Duration `json:"prometheus_retention_time,omitempty" mapstructure:"prometheus_retention_time"`
-
 	// FilterDefault is the default for whether to allow a metric that's not
 	// covered by the filter.
 	//
@@ -199,6 +191,13 @@ type TelemetryConfig struct {
 	//
 	// hcl: telemetry { statsite_address = string }
 	StatsiteAddr string `json:"statsite_address,omitempty" mapstructure:"statsite_address"`
+
+	// PrometheusOpts provides configuration for the PrometheusSink. Currently the only configuration
+	// we acquire from hcl is the retention time. We also use definition slices that are set in agent setup
+	// before being passed to InitTelemmetry.
+	//
+	// hcl: telemetry { prometheus_retention_time = "duration" }
+	PrometheusOpts prometheus.PrometheusOpts
 }
 
 // MergeDefaults copies any non-zero field from defaults into the current
@@ -276,17 +275,17 @@ func dogstatdSink(cfg TelemetryConfig, hostname string) (metrics.MetricSink, err
 	return sink, nil
 }
 
-func prometheusSink(cfg TelemetryConfig, hostname string, defs PrometheusDefs) (metrics.MetricSink, error) {
+func prometheusSink(cfg TelemetryConfig, hostname string) (metrics.MetricSink, error) {
 
-	if cfg.PrometheusRetentionTime.Nanoseconds() < 1 {
+	if cfg.PrometheusOpts.Expiration.Nanoseconds() < 1 {
 		return nil, nil
 	}
 
 	prometheusOpts := prometheus.PrometheusOpts{
-		Expiration:         cfg.PrometheusRetentionTime,
-		GaugeDefinitions:   defs.Gauges,
-		CounterDefinitions: defs.Counters,
-		SummaryDefinitions: defs.Summaries,
+		Expiration:         cfg.PrometheusOpts.Expiration,
+		GaugeDefinitions:   cfg.PrometheusOpts.GaugeDefinitions,
+		CounterDefinitions: cfg.PrometheusOpts.CounterDefinitions,
+		SummaryDefinitions: cfg.PrometheusOpts.SummaryDefinitions,
 	}
 	sink, err := prometheus.NewPrometheusSinkFrom(prometheusOpts)
 	if err != nil {
@@ -337,25 +336,9 @@ func circonusSink(cfg TelemetryConfig, hostname string) (metrics.MetricSink, err
 	return sink, nil
 }
 
-// PrometheusDefs wraps collections of metric definitions to pass into the PrometheusSink
-type PrometheusDefs struct {
-	Gauges    []prometheus.GaugeDefinition
-	Counters  []prometheus.CounterDefinition
-	Summaries []prometheus.SummaryDefinition
-}
-
-// EmptyPrometheusDefs returns a PrometheusDefs struct where each of the slices have zero elements, but not nil.
-func EmptyPrometheusDefs() PrometheusDefs {
-	return PrometheusDefs{
-		Gauges:    []prometheus.GaugeDefinition{},
-		Counters:  []prometheus.CounterDefinition{},
-		Summaries: []prometheus.SummaryDefinition{},
-	}
-}
-
 // InitTelemetry configures go-metrics based on map of telemetry config
 // values as returned by Runtimecfg.Config().
-func InitTelemetry(cfg TelemetryConfig, defs PrometheusDefs) (*metrics.InmemSink, error) {
+func InitTelemetry(cfg TelemetryConfig) (*metrics.InmemSink, error) {
 	if cfg.Disable {
 		return nil, nil
 	}
@@ -395,7 +378,7 @@ func InitTelemetry(cfg TelemetryConfig, defs PrometheusDefs) (*metrics.InmemSink
 		return nil, err
 	}
 
-	promSink, err := prometheusSink(cfg, metricsConf.HostName, defs)
+	promSink, err := prometheusSink(cfg, metricsConf.HostName)
 	if err != nil {
 		return nil, err
 	}