Added metrics for bascule (#405)

* Added metrics for bascule

* Small Fixes

* removed json tags

* added nil check

* updated glide

basculechecks/metricListener.go

@@ -0,0 +1,82 @@
+package basculechecks
+
+import (
+	"time"
+
+	"github.com/Comcast/comcast-bascule/bascule"
+	"github.com/Comcast/comcast-bascule/bascule/basculehttp"
+	"github.com/SermoDigital/jose/jwt"
+)
+
+type MetricListener struct {
+	expLeeway time.Duration
+	nbfLeeway time.Duration
+	measures  *JWTValidationMeasures
+}
+
+func (m *MetricListener) OnAuthenticated(auth bascule.Authentication) {
+	now := time.Now()
+
+	if m.measures == nil {
+		return // measure tools are not defined, skip
+	}
+
+	if auth.Token == nil {
+		return
+	}
+
+	c, ok := auth.Token.Attributes().Get("claims")
+	if !ok {
+		return // if there aren't any claims, skip
+	}
+	claims, ok := c.(jwt.Claims)
+	if !ok {
+		return // if claims aren't what we expect, skip
+	}
+
+	//how far did we land from the NBF (in seconds): ie. -1 means 1 sec before, 1 means 1 sec after
+	if nbf, nbfPresent := claims.NotBefore(); nbfPresent {
+		nbf = nbf.Add(-m.nbfLeeway)
+		offsetToNBF := now.Sub(nbf).Seconds()
+		m.measures.NBFHistogram.Observe(offsetToNBF)
+	}
+
+	//how far did we land from the EXP (in seconds): ie. -1 means 1 sec before, 1 means 1 sec after
+	if exp, expPresent := claims.Expiration(); expPresent {
+		exp = exp.Add(m.expLeeway)
+		offsetToEXP := now.Sub(exp).Seconds()
+		m.measures.ExpHistogram.Observe(offsetToEXP)
+	}
+}
+
+func (m *MetricListener) OnErrorResponse(e basculehttp.ErrorResponseReason, _ error) {
+	if m.measures == nil {
+		return
+	}
+	m.measures.ValidationReason.With(ReasonLabel, e.String()).Add(1)
+}
+
+type Option func(m *MetricListener)
+
+func WithExpLeeway(e time.Duration) Option {
+	return func(m *MetricListener) {
+		m.expLeeway = e
+	}
+}
+
+func WithNbfLeeway(n time.Duration) Option {
+	return func(m *MetricListener) {
+		m.nbfLeeway = n
+	}
+}
+
+func NewMetricListener(m *JWTValidationMeasures, options ...Option) *MetricListener {
+	listener := MetricListener{
+		measures: m,
+	}
+
+	for _, o := range options {
+		o(&listener)
+	}
+	return &listener
+}

basculechecks/metrics.go

@@ -0,0 +1,59 @@
+package basculechecks
+
+import (
+	"github.com/Comcast/webpa-common/xmetrics"
+	"github.com/go-kit/kit/metrics"
+	gokitprometheus "github.com/go-kit/kit/metrics/prometheus"
+)
+
+//Names for our metrics
+const (
+	JWTValidationReasonCounter = "jwt_validation_reason"
+	NBFHistogram               = "jwt_from_nbf_seconds"
+	EXPHistogram               = "jwt_from_exp_seconds"
+)
+
+// labels
+const (
+	ReasonLabel = "reason"
+)
+
+//Metrics returns the Metrics relevant to this package
+func Metrics() []xmetrics.Metric {
+	return []xmetrics.Metric{
+		xmetrics.Metric{
+			Name:       JWTValidationReasonCounter,
+			Type:       xmetrics.CounterType,
+			Help:       "Counter for validation resolutions per reason",
+			LabelNames: []string{ReasonLabel},
+		},
+		xmetrics.Metric{
+			Name:    NBFHistogram,
+			Type:    xmetrics.HistogramType,
+			Help:    "Difference (in seconds) between time of JWT validation and nbf (including leeway)",
+			Buckets: []float64{-61, -11, -2, -1, 0, 9, 60}, // defines the upper inclusive (<=) bounds
+		},
+		xmetrics.Metric{
+			Name:    EXPHistogram,
+			Type:    xmetrics.HistogramType,
+			Help:    "Difference (in seconds) between time of JWT validation and exp (including leeway)",
+			Buckets: []float64{-61, -11, -2, -1, 0, 9, 60},
+		},
+	}
+}
+
+//JWTValidationMeasures describes the defined metrics that will be used by clients
+type JWTValidationMeasures struct {
+	NBFHistogram     *gokitprometheus.Histogram
+	ExpHistogram     *gokitprometheus.Histogram
+	ValidationReason metrics.Counter
+}
+
+//NewJWTValidationMeasures realizes desired metrics
+func NewJWTValidationMeasures(r xmetrics.Registry) *JWTValidationMeasures {
+	return &JWTValidationMeasures{
+		NBFHistogram:     gokitprometheus.NewHistogram(r.NewHistogramVec(NBFHistogram)),
+		ExpHistogram:     gokitprometheus.NewHistogram(r.NewHistogramVec(EXPHistogram)),
+		ValidationReason: r.NewCounter(JWTValidationReasonCounter),
+	}
+}

basculechecks/metrics_test.go

@@ -0,0 +1,17 @@
+package basculechecks
+
+import (
+	"testing"
+
+	"github.com/Comcast/webpa-common/xmetrics"
+	"github.com/stretchr/testify/assert"
+)
+
+func newTestJWTValidationMeasure() *JWTValidationMeasures {
+	return NewJWTValidationMeasures(xmetrics.MustNewRegistry(nil, Metrics))
+}
+
+func TestSimpleRun(t *testing.T) {
+	assert := assert.New(t)
+	assert.NotNil(newTestJWTValidationMeasure())
+}

glide.yaml

@@ -65,3 +65,5 @@ import:
   version: v0.9.2
 - package: github.com/miekg/dns
   version: v1.0.12
+- package: github.com/Comcast/comcast-bascule
+  version: v0.2.5