Issue #151: Add support for Circonus metrics

This patch adds support for sending metrics
to Circonus (http://circonus.com).

The code is squashed from PR #150 with minor
edits and was written by @maier.

config/config.go

@@ -67,11 +67,16 @@ type Runtime struct {
 }
 
 type Metrics struct {
-	Target       string
-	Prefix       string
-	Interval     time.Duration
-	GraphiteAddr string
-	StatsDAddr   string
+	Target           string
+	Prefix           string
+	Interval         time.Duration
+	GraphiteAddr     string
+	StatsDAddr       string
+	CirconusAPIKey   string
+	CirconusAPIApp   string
+	CirconusAPIURL   string
+	CirconusCheckID  string
+	CirconusBrokerID string
 }
 
 type Registry struct {

config/default.go

@@ -40,8 +40,9 @@ var Default = &Config{
 		Color: "light-green",
 	},
 	Metrics: Metrics{
-		Prefix:   "default",
-		Interval: 30 * time.Second,
+		Prefix:         "default",
+		Interval:       30 * time.Second,
+		CirconusAPIApp: "fabio",
 	},
 	CertSources: map[string]CertSource{},
 }

config/load.go

@@ -110,6 +110,11 @@ func load(p *properties.Properties) (cfg *Config, err error) {
 	f.DurationVar(&cfg.Metrics.Interval, "metrics.interval", Default.Metrics.Interval, "metrics reporting interval")
 	f.StringVar(&cfg.Metrics.GraphiteAddr, "metrics.graphite.addr", Default.Metrics.GraphiteAddr, "graphite server address")
 	f.StringVar(&cfg.Metrics.StatsDAddr, "metrics.statsd.addr", Default.Metrics.StatsDAddr, "statsd server address")
+	f.StringVar(&cfg.Metrics.CirconusAPIKey, "metrics.circonus.apikey", Default.Metrics.CirconusAPIKey, "Circonus API token key")
+	f.StringVar(&cfg.Metrics.CirconusAPIApp, "metrics.circonus.apiapp", Default.Metrics.CirconusAPIApp, "Circonus API token app")
+	f.StringVar(&cfg.Metrics.CirconusAPIURL, "metrics.circonus.apiurl", Default.Metrics.CirconusAPIURL, "Circonus API URL")
+	f.StringVar(&cfg.Metrics.CirconusBrokerID, "metrics.circonus.brokerid", Default.Metrics.CirconusBrokerID, "Circonus Broker ID")
+	f.StringVar(&cfg.Metrics.CirconusCheckID, "metrics.circonus.checkid", Default.Metrics.CirconusCheckID, "Circonus Check ID")
 	f.StringVar(&cfg.Registry.Backend, "registry.backend", Default.Registry.Backend, "registry backend")
 	f.StringVar(&cfg.Registry.File.Path, "registry.file.path", Default.Registry.File.Path, "path to file based routing table")
 	f.StringVar(&cfg.Registry.Static.Routes, "registry.static.routes", Default.Registry.Static.Routes, "static routes")

config/load_test.go

@@ -47,6 +47,12 @@ metrics.target = graphite
 metrics.prefix = someprefix
 metrics.interval = 5s
 metrics.graphite.addr = 5.6.7.8:9999
+metrics.statsd.addr = 6.7.8.9:9999
+metrics.circonus.apikey = circonus-apikey
+metrics.circonus.apiapp = circonus-apiapp
+metrics.circonus.apiurl = circonus-apiurl
+metrics.circonus.brokerid = circonus-brokerid
+metrics.circonus.checkid = circonus-checkid
 runtime.gogc = 666
 runtime.gomaxprocs = 12
 ui.addr = 7.8.9.0:1234
@@ -117,10 +123,16 @@ aws.apigw.cert.cn = furb
 			},
 		},
 		Metrics: Metrics{
-			Target:       "graphite",
-			Prefix:       "someprefix",
-			Interval:     5 * time.Second,
-			GraphiteAddr: "5.6.7.8:9999",
+			Target:           "graphite",
+			Prefix:           "someprefix",
+			Interval:         5 * time.Second,
+			GraphiteAddr:     "5.6.7.8:9999",
+			StatsDAddr:       "6.7.8.9:9999",
+			CirconusAPIKey:   "circonus-apikey",
+			CirconusAPIApp:   "circonus-apiapp",
+			CirconusAPIURL:   "circonus-apiurl",
+			CirconusBrokerID: "circonus-brokerid",
+			CirconusCheckID:  "circonus-checkid",
 		},
 		Runtime: Runtime{
 			GOGC:       666,

fabio.properties

@@ -462,6 +462,7 @@
 #  stdout:   report metrics to stdout
 #  graphite: report metrics to Graphite on ${metrics.graphite.addr}
 #  statsd: report metrics to StatsD on ${metrics.statsd.addr}
+#  circonus: report metrics to Circonus (http://circonus.com/)
 #
 # The default is
 #
@@ -505,6 +506,56 @@
 # metrics.statsd.addr =
 
 
+# metrics.circonus.apikey configures the API token key to use when
+# submitting metrics to Circonus. See: https://login.circonus.com/user/tokens
+# This is required when ${metrics.target} is set to "circonus".
+#
+# The default is
+#
+# metrics.circonus.apikey =
+
+
+# metrics.circonus.apiapp configures the API token app to use when
+# submitting metrics to Circonus. See: https://login.circonus.com/user/tokens
+# This is optional when ${metrics.target} is set to "circonus".
+#
+# The default is
+#
+# metrics.circonus.apiapp = fabio
+
+
+# metrics.circonus.apiurl configures the API URL to use when
+# submitting metrics to Circonus. https://api.circonus.com/v2/
+# will be used if no specific URL is provided.
+# This is optional when ${metrics.target} is set to "circonus".
+#
+# The default is
+#
+# metrics.circonus.apiurl =
+
+
+# metrics.circonus.brokerid configures a specific broker to use when
+# creating a check for submitting metrics to Circonus.
+# This is optional when ${metrics.target} is set to "circonus".
+# Optional for public brokers, required for Inside brokers.
+# Only applicable if a check is being created.
+#
+# The default is
+#
+# metrics.circonus.brokerid =
+
+
+# metrics.circonus.checkid configures a specific check to use when
+# submitting metrics to Circonus.
+# This is optional when ${metrics.target} is set to "circonus".
+# An attempt will be made to search for a previously created check,
+# if no applicable check is found, one will be created.
+#
+# The default is
+#
+# metrics.circonus.checkid =
+
+
 # runtime.gogc configures GOGC (the GC target percentage).
 #
 # Setting runtime.gogc is equivalent to setting the GOGC

metrics/circonus.go

@@ -0,0 +1,130 @@
+package metrics
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"sync"
+	"time"
+
+	cgm "github.com/circonus-labs/circonus-gometrics"
+)
+
+var (
+	circonus *cgmRegistry
+	once     sync.Once
+)
+
+const serviceName = "fabio"
+
+// circonusRegistry returns a provider that reports to Circonus.
+func circonusRegistry(prefix string,
+	circKey string,
+	circApp string,
+	circURL string,
+	circBrokerID string,
+	circCheckID string,
+	interval time.Duration) (Registry, error) {
+
+	var initError error
+
+	once.Do(func() {
+		if circKey == "" {
+			initError = errors.New("metrics: Circonus API token key")
+			return
+		}
+
+		if circApp == "" {
+			circApp = serviceName
+		}
+
+		host, err := os.Hostname()
+		if err != nil {
+			initError = fmt.Errorf("metrics: unable to initialize Circonus %s", err)
+			return
+		}
+
+		cfg := &cgm.Config{}
+
+		cfg.CheckManager.API.TokenKey = circKey
+		cfg.CheckManager.API.TokenApp = circApp
+		cfg.CheckManager.API.URL = circURL
+		cfg.CheckManager.Check.ID = circCheckID
+		cfg.CheckManager.Broker.ID = circBrokerID
+		cfg.Interval = fmt.Sprintf("%.0fs", interval.Seconds())
+		cfg.CheckManager.Check.InstanceID = host
+		cfg.CheckManager.Check.DisplayName = fmt.Sprintf("%s /%s", host, serviceName)
+		cfg.CheckManager.Check.SearchTag = fmt.Sprintf("service:%s", serviceName)
+
+		metrics, err := cgm.NewCirconusMetrics(cfg)
+		if err != nil {
+			initError = fmt.Errorf("metrics: unable to initialize Circonus %s", err)
+			return
+		}
+
+		circonus = &cgmRegistry{metrics, prefix}
+
+		metrics.Start()
+
+		log.Print("[INFO] Sending metrics to Circonus")
+	})
+
+	return circonus, initError
+}
+
+type cgmRegistry struct {
+	metrics *cgm.CirconusMetrics
+	prefix  string
+}
+
+// Names is not supported by Circonus.
+func (m *cgmRegistry) Names() []string { return nil }
+
+// Unregister is implicitly supported by Circonus,
+// stop submitting the metric and it stops being sent to Circonus.
+func (m *cgmRegistry) Unregister(name string) {}
+
+// UnregisterAll is implicitly supported by Circonus,
+// stop submitting metrics and they will no longer be sent to Circonus.
+func (m *cgmRegistry) UnregisterAll() {}
+
+// GetCounter returns a counter for the given metric name.
+func (m *cgmRegistry) GetCounter(name string) Counter {
+	metricName := fmt.Sprintf("%s`%s", m.prefix, name)
+	return &cgmCounter{m.metrics, metricName}
+}
+
+// GetTimer returns a timer for the given metric name.
+func (m *cgmRegistry) GetTimer(name string) Timer {
+	metricName := fmt.Sprintf("%s`%s", m.prefix, name)
+	return &cgmTimer{m.metrics, metricName}
+}
+
+type cgmCounter struct {
+	metrics *cgm.CirconusMetrics
+	name    string
+}
+
+// Inc increases the counter by n.
+func (c *cgmCounter) Inc(n int64) {
+	c.metrics.IncrementByValue(c.name, uint64(n))
+}
+
+type cgmTimer struct {
+	metrics *cgm.CirconusMetrics
+	name    string
+}
+
+// Percentile is not supported by Circonus.
+func (t *cgmTimer) Percentile(nth float64) float64 { return 0 }
+
+// Rate1 is not supported by Circonus.
+func (t *cgmTimer) Rate1() float64 { return 0 }
+
+// UpdateSince adds delta between start and current time as
+// a sample to a histogram. The histogram is created if it
+// does not already exist.
+func (t *cgmTimer) UpdateSince(start time.Time) {
+	t.metrics.Timing(t.name, float64(time.Since(start)))
+}

metrics/circonus_test.go

@@ -0,0 +1,83 @@
+package metrics
+
+import (
+	"os"
+	"testing"
+	"time"
+)
+
+func TestRegistry(t *testing.T) {
+	t.Log("Testing registry interface")
+
+	p := &cgmRegistry{}
+
+	t.Log("\tNames()")
+	names := p.Names()
+	if names != nil {
+		t.Errorf("Expected nil got '%+v'", names)
+	}
+
+	t.Log("\tUnregister()")
+	p.Unregister("foo")
+
+	t.Log("\tUnregisterAll()")
+	p.UnregisterAll()
+
+	t.Log("\tGetTimer()")
+	timer := p.GetTimer("foo")
+	if timer == nil {
+		t.Error("Expected a timer, got nil")
+	}
+}
+
+func TestTimer(t *testing.T) {
+	t.Log("Testing timer interface")
+
+	timer := &cgmTimer{}
+
+	t.Log("\tPercentile()")
+	pct := timer.Percentile(99.9)
+	if pct != 0 {
+		t.Errorf("Expected 0 got '%+v'", pct)
+	}
+
+	t.Log("\tRate1()")
+	rate := timer.Rate1()
+	if rate != 0 {
+		t.Errorf("Expected 0 got '%+v'", rate)
+	}
+}
+
+func TestAll(t *testing.T) {
+	start := time.Now()
+
+	if os.Getenv("CIRCONUS_API_TOKEN") == "" {
+		t.Skip("skipping test; $CIRCONUS_API_TOKEN not set")
+	}
+
+	t.Log("Testing cgm functionality -- this *will* create/use a check")
+
+	apiKey := os.Getenv("CIRCONUS_API_TOKEN")
+	apiApp := os.Getenv("CIRCONUS_API_APP")
+	apiURL := os.Getenv("CIRCONUS_API_URL")
+	brokerID := os.Getenv("CIRCONUS_BROKER_ID")
+	checkID := os.Getenv("CIRCONUS_CHECK_ID")
+
+	interval, err := time.ParseDuration("60s")
+	if err != nil {
+		t.Fatalf("Unable to parse interval %+v", err)
+	}
+
+	circ, err := circonusRegistry("test", apiKey, apiApp, apiURL, brokerID, checkID, interval)
+	if err != nil {
+		t.Fatalf("Unable to initialize Circonus +%v", err)
+	}
+
+	counter := circ.GetCounter("fooCounter")
+	counter.Inc(3)
+
+	timer := circ.GetTimer("fooTimer")
+	timer.UpdateSince(start)
+
+	circonus.metrics.Flush()
+}

metrics/metrics.go

@@ -39,6 +39,15 @@ func NewRegistry(cfg config.Metrics) (r Registry, err error) {
 		log.Printf("[INFO] Sending metrics to StatsD on %s as %q", cfg.StatsDAddr, prefix)
 		return gmStatsDRegistry(prefix, cfg.StatsDAddr, cfg.Interval)
 
+	case "circonus":
+		return circonusRegistry(prefix,
+			cfg.CirconusAPIKey,
+			cfg.CirconusAPIApp,
+			cfg.CirconusAPIURL,
+			cfg.CirconusBrokerID,
+			cfg.CirconusCheckID,
+			cfg.Interval)
+
 	default:
 		exit.Fatal("[FATAL] Invalid metrics target ", cfg.Target)
 	}