Merge ff8df00 into af594cd

go.mod

@@ -3,15 +3,7 @@ module github.com/cabify/gotoprom
 go 1.12
 
 require (
-	github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973 // indirect
-	github.com/gogo/protobuf v1.2.1 // indirect
-	github.com/golang/protobuf v1.2.0 // indirect
-	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
-	github.com/prometheus/client_golang v0.9.1
-	github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 // indirect
-	github.com/prometheus/common v0.0.0-20181020173914-7e9e6cabbd39 // indirect
-	github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d // indirect
+	github.com/prometheus/client_golang v1.0.0
 	github.com/stretchr/objx v0.2.0 // indirect
 	github.com/stretchr/testify v1.3.0
-	golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6 // indirect
 )

go.sum

@@ -1,31 +1,62 @@
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973 h1:xJ4a3vCFaGF/jqvzLMYoU8P317H5OQ+Via4RmuPwCS0=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
+github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
-github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
+github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
+github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
+github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
-github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
+github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
+github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
+github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v0.9.1 h1:K47Rk0v/fkEfwfQet2KWhscE0cJzjgCCDBG2KHZoVno=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_golang v1.0.0 h1:vrDKnkGzuGvhNAL56c7DBz29ZL+KxnoR0x7enabFceM=
+github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
-github.com/prometheus/common v0.0.0-20181020173914-7e9e6cabbd39 h1:Cto4X6SVMWRPBkJ/3YHn1iDGDGc/Z+sW+AEMKHMVvN4=
-github.com/prometheus/common v0.0.0-20181020173914-7e9e6cabbd39/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
+github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/common v0.4.1 h1:K0MGApIoQvMw27RTdJkPbr3JZ7DNbtxQNyi5STVM6Kw=
+github.com/prometheus/common v0.4.1/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d h1:GoAlyOgbOEIFdaDqxJVlbOQ1DtGmZWs/Qau0hIlk+WQ=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+github.com/prometheus/procfs v0.0.2 h1:6LJUbpNm42llc4HRCuvApCSWB/WfhuNo9K98Q9sNGfs=
+github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
+github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.2.0 h1:Hbg2NidpLE8veEBkEZTL3CvlkUIVzuU9jDplZO54c48=
 github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
-golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6 h1:bjcUS9ztw9kFmmIxJInhon/0Is3p+EHBKNgquIzo1OI=
-golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5 h1:mzjBh+S5frKOsOBobWIMAbXavqjmgO17k/2puhcFR94=
+golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

prometheusvanilla/builders.go

@@ -2,6 +2,7 @@ package prometheusvanilla
 
 import (
 	"fmt"
+	"math"
 	"reflect"
 	"strconv"
 	"strings"
@@ -85,13 +86,14 @@ func BuildSummary(name, help, namespace string, labelNames []string, tag reflect
 	if err != nil {
 		return nil, nil, fmt.Errorf("build summary %q: %s", name, err)
 	}
-
+	objectives, err := objectivesFromTag(tag)
 	sum := prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
-			Name:      name,
-			Help:      help,
-			Namespace: namespace,
-			MaxAge:    maxAge,
+			Name:       name,
+			Help:       help,
+			Namespace:  namespace,
+			MaxAge:     maxAge,
+			Objectives: objectives,
 		},
 		labelNames,
 	)
@@ -135,3 +137,32 @@ func maxAgeFromTag(tag reflect.StructTag) (time.Duration, error) {
 	}
 	return maxAgeDuration, nil
 }
+
+func objectivesFromTag(tag reflect.StructTag) (map[float64]float64, error) {
+	quantileString, ok := tag.Lookup("objectives")
+	if !ok {
+		return DefaultObjectives(), nil
+	}
+	quantileSlice := strings.Split(quantileString, ",")
+	objectives := make(map[float64]float64, len(quantileSlice))
+	for _, quantile := range quantileSlice {
+		q, err := strconv.ParseFloat(quantile, 64)
+		if err != nil {
+			return nil, fmt.Errorf("invalid objective specified: %s", err)
+		}
+		objectives[q] = absError(q)
+	}
+	return objectives, nil
+}
+
+// DefaultObjectives provides a list of objectives you can use when you don't know what to use yet.
+func DefaultObjectives() map[float64]float64 {
+	return map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
+}
+
+// absError will calculate the absolute error for a given objective up to 3 decimal places.
+// The variance is calculated based on the given quantile.
+// Values in lower quantiles have a higher probability of being similar, so we can apply greater variances.
+func absError(obj float64) float64 {
+	return math.Round((0.1*(1-obj))*1000) / 1000
+}

prometheusvanilla/builders_test.go

@@ -1,6 +1,7 @@
 package prometheusvanilla
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
 	"time"
@@ -16,13 +17,16 @@ const (
 )
 
 var (
-	labels                            = make(prometheus.Labels, 2)
-	keys                              = make([]string, 0, len(labels))
-	defaultTag      reflect.StructTag = `name:"some_name" help:"some help for the metric"`
-	bucketsTag      reflect.StructTag = `name:"some_name" help:"some help for the metric" buckets:"0.001,0.005,0.01,0.05,0.1,0.5,1,5,10"`
-	maxAgeTag       reflect.StructTag = `name:"some_name" help:"some help for the metric" max_age:"1h"`
-	expectedBuckets                   = []float64{0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 5, 10}
-	expectedMaxAge                    = time.Hour
+	labels                                   = make(prometheus.Labels, 2)
+	keys                                     = make([]string, 0, len(labels))
+	defaultTag             reflect.StructTag = `name:"some_name" help:"some help for the metric"`
+	bucketsTag             reflect.StructTag = `name:"some_name" help:"some help for the metric" buckets:"0.001,0.005,0.01,0.05,0.1,0.5,1,5,10"`
+	maxAgeTag              reflect.StructTag = `name:"some_name" help:"some help for the metric" max_age:"1h"`
+	objectivesTag          reflect.StructTag = `name:"some_name" help:"some help for the metric" max_age:"1h" objectives:"0.55,0.95,0.98"`
+	objectivesMalformedTag reflect.StructTag = `name:"some_name" help:"some help for the metric" max_age:"1h" objectives:"notFloat"`
+	expectedBuckets                          = []float64{0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 5, 10}
+	expectedMaxAge                           = time.Hour
+	expectedObjectives                       = map[float64]float64{0.55: 0.045, 0.95: 0.005, 0.98: 0.002}
 )
 
 func TestBuilders(t *testing.T) {
@@ -62,7 +66,7 @@ func TestBuilders(t *testing.T) {
 	})
 
 	t.Run("Test building a summary with malformed max_age", func(t *testing.T) {
-		_, _, err := BuildSummary(name, help, nameSpace, keys, `max_age:"one year"`)
+		_, _, err := BuildSummary(name, help, nameSpace, keys, `max_age:"one year" objectives:"0.1,0.25"`)
 		assert.Error(t, err)
 	})
 }
@@ -85,15 +89,53 @@ func TestMaxAge(t *testing.T) {
 	t.Run("Test it retrieves custom max_age", func(t *testing.T) {
 		maxAge, err := maxAgeFromTag(maxAgeTag)
 		assert.NoError(t, err)
-		assert.Equal(t, maxAge, expectedMaxAge)
+		assert.Equal(t, expectedMaxAge, maxAge)
 	})
 	t.Run("Test it returns 0 when no max_age is found", func(t *testing.T) {
 		maxAge, err := maxAgeFromTag(defaultTag)
 		assert.NoError(t, err)
-		assert.Equal(t, maxAge, time.Duration(0))
+		assert.Equal(t, time.Duration(0), maxAge)
 	})
 }
 
+func TestObjectives(t *testing.T) {
+	t.Run("Test parsing objectives from tag", func(t *testing.T) {
+		obj, err := objectivesFromTag(objectivesTag)
+		assert.NoError(t, err)
+		assert.Equal(t, expectedObjectives, obj)
+	})
+	t.Run("Test returning default objective values when none are specified", func(t *testing.T) {
+		obj, err := objectivesFromTag(defaultTag)
+		assert.NoError(t, err)
+		assert.Equal(t, DefaultObjectives(), obj)
+	})
+	t.Run("Test returning default objective values when none are specified", func(t *testing.T) {
+		obj, err := objectivesFromTag(objectivesMalformedTag)
+		assert.Error(t, err)
+		assert.Nil(t, obj)
+	})
+}
+
+func TestAbsError(t *testing.T) {
+	tests := []struct {
+		objective float64
+		absErr    float64
+	}{
+		{0.5, 0.05},
+		{0.99, 0.001},
+		{0.999, 0},
+		{0, 0.1},
+		{-10, 1.1},
+	}
+
+	for _, test := range tests {
+		t.Run(fmt.Sprintf("Test calculate absolute error for obejctive %2f", test.objective), func(t *testing.T) {
+			e := absError(test.objective)
+			assert.Equal(t, test.absErr, e)
+		})
+	}
+}
+
 func initLabels() {
 	labels["labels1"] = "labels"
 	labels["labels2"] = "labels"