From fae2f6306b16a7265d5569c5507623dfaba09053 Mon Sep 17 00:00:00 2001 From: Quentin D <4972091+Okhoshi@users.noreply.github.com> Date: Tue, 13 Dec 2022 13:47:52 +0100 Subject: [PATCH] Add constrained labels and Constrained variant for all MetricVecs (#1151) * Introduce MetricVecOpts and add constraints to VariableLabels MetricVecOpts exposes options specific to MetricVec initialisation. The first option exposed by MetricVecOpts are constraints on VariableLabels, allowing restrictions on the possible values a label can take, to prevent cardinality explosion when the label value comes from a non-trusted source (as a user input or HTTP header). Signed-off-by: Quentin Devos <4972091+Okhoshi@users.noreply.github.com> * Add tests Signed-off-by: Quentin Devos <4972091+Okhoshi@users.noreply.github.com> Signed-off-by: Quentin Devos <4972091+Okhoshi@users.noreply.github.com> --- prometheus/counter.go | 26 ++- prometheus/counter_test.go | 2 +- prometheus/desc.go | 34 +++- prometheus/examples_test.go | 4 +- prometheus/gauge.go | 26 ++- prometheus/histogram.go | 30 ++- prometheus/labels.go | 72 ++++++++ prometheus/registry.go | 2 +- prometheus/summary.go | 32 +++- prometheus/value.go | 4 +- prometheus/vec.go | 54 +++++- prometheus/vec_test.go | 359 +++++++++++++++++++++++++++++++++++- prometheus/vnext.go | 23 +++ prometheus/wrap.go | 2 +- 14 files changed, 626 insertions(+), 44 deletions(-) create mode 100644 prometheus/vnext.go diff --git a/prometheus/counter.go b/prometheus/counter.go index a912b75..62de4dc 100644 --- a/prometheus/counter.go +++ b/prometheus/counter.go @@ -59,6 +59,18 @@ type ExemplarAdder interface { // CounterOpts is an alias for Opts. See there for doc comments. type CounterOpts Opts +// CounterVecOpts bundles the options to create a CounterVec metric. +// It is mandatory to set CounterOpts, see there for mandatory fields. VariableLabels +// is optional and can safely be left to its default value. +type CounterVecOpts struct { + CounterOpts + + // VariableLabels are used to partition the metric vector by the given set + // of labels. Each label value will be constrained with the optional Contraint + // function, if provided. + VariableLabels ConstrainableLabels +} + // NewCounter creates a new Counter based on the provided CounterOpts. // // The returned implementation also implements ExemplarAdder. It is safe to @@ -174,16 +186,24 @@ type CounterVec struct { // NewCounterVec creates a new CounterVec based on the provided CounterOpts and // partitioned by the given label names. func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec { - desc := NewDesc( + return V2.NewCounterVec(CounterVecOpts{ + CounterOpts: opts, + VariableLabels: UnconstrainedLabels(labelNames), + }) +} + +// NewCounterVec creates a new CounterVec based on the provided CounterVecOpts. +func (v2) NewCounterVec(opts CounterVecOpts) *CounterVec { + desc := V2.NewDesc( BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), opts.Help, - labelNames, + opts.VariableLabels, opts.ConstLabels, ) return &CounterVec{ MetricVec: NewMetricVec(desc, func(lvs ...string) Metric { if len(lvs) != len(desc.variableLabels) { - panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs)) + panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.labelNames(), lvs)) } result := &counter{desc: desc, labelPairs: MakeLabelPairs(desc, lvs), now: time.Now} result.init(result) // Init self-collection. diff --git a/prometheus/counter_test.go b/prometheus/counter_test.go index 9398e28..40f5ab1 100644 --- a/prometheus/counter_test.go +++ b/prometheus/counter_test.go @@ -102,7 +102,7 @@ func TestCounterVecGetMetricWithInvalidLabelValues(t *testing.T) { Name: "test", }, []string{"a"}) - labelValues := make([]string, len(test.labels)) + labelValues := make([]string, 0, len(test.labels)) for _, val := range test.labels { labelValues = append(labelValues, val) } diff --git a/prometheus/desc.go b/prometheus/desc.go index 5b1a7c0..3fa0069 100644 --- a/prometheus/desc.go +++ b/prometheus/desc.go @@ -53,9 +53,9 @@ type Desc struct { // constLabelPairs contains precalculated DTO label pairs based on // the constant labels. constLabelPairs []*dto.LabelPair - // variableLabels contains names of labels for which the metric - // maintains variable values. - variableLabels []string + // variableLabels contains names of labels and normalization function for + // which the metric maintains variable values. + variableLabels ConstrainedLabels // id is a hash of the values of the ConstLabels and fqName. This // must be unique among all registered descriptors and can therefore be // used as an identifier of the descriptor. @@ -79,10 +79,24 @@ type Desc struct { // For constLabels, the label values are constant. Therefore, they are fully // specified in the Desc. See the Collector example for a usage pattern. func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc { + return V2.NewDesc(fqName, help, UnconstrainedLabels(variableLabels), constLabels) +} + +// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc +// and will be reported on registration time. variableLabels and constLabels can +// be nil if no such labels should be set. fqName must not be empty. +// +// variableLabels only contain the label names and normalization functions. Their +// label values are variable and therefore not part of the Desc. (They are managed +// within the Metric.) +// +// For constLabels, the label values are constant. Therefore, they are fully +// specified in the Desc. See the Collector example for a usage pattern. +func (v2) NewDesc(fqName, help string, variableLabels ConstrainableLabels, constLabels Labels) *Desc { d := &Desc{ fqName: fqName, help: help, - variableLabels: variableLabels, + variableLabels: variableLabels.constrainedLabels(), } if !model.IsValidMetricName(model.LabelValue(fqName)) { d.err = fmt.Errorf("%q is not a valid metric name", fqName) @@ -92,7 +106,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) * // their sorted label names) plus the fqName (at position 0). labelValues := make([]string, 1, len(constLabels)+1) labelValues[0] = fqName - labelNames := make([]string, 0, len(constLabels)+len(variableLabels)) + labelNames := make([]string, 0, len(constLabels)+len(d.variableLabels)) labelNameSet := map[string]struct{}{} // First add only the const label names and sort them... for labelName := range constLabels { @@ -117,13 +131,13 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) * // Now add the variable label names, but prefix them with something that // cannot be in a regular label name. That prevents matching the label // dimension with a different mix between preset and variable labels. - for _, labelName := range variableLabels { - if !checkLabelName(labelName) { - d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName) + for _, label := range d.variableLabels { + if !checkLabelName(label.Name) { + d.err = fmt.Errorf("%q is not a valid label name for metric %q", label.Name, fqName) return d } - labelNames = append(labelNames, "$"+labelName) - labelNameSet[labelName] = struct{}{} + labelNames = append(labelNames, "$"+label.Name) + labelNameSet[label.Name] = struct{}{} } if len(labelNames) != len(labelNameSet) { d.err = fmt.Errorf("duplicate label names in constant and variable labels for metric %q", fqName) diff --git a/prometheus/examples_test.go b/prometheus/examples_test.go index a868262..047a1f6 100644 --- a/prometheus/examples_test.go +++ b/prometheus/examples_test.go @@ -294,9 +294,9 @@ func ExampleRegister() { // Output: // taskCounter registered. - // taskCounterVec not registered: a previously registered descriptor with the same fully-qualified name as Desc{fqName: "worker_pool_completed_tasks_total", help: "Total number of tasks completed.", constLabels: {}, variableLabels: [worker_id]} has different label names or a different help string + // taskCounterVec not registered: a previously registered descriptor with the same fully-qualified name as Desc{fqName: "worker_pool_completed_tasks_total", help: "Total number of tasks completed.", constLabels: {}, variableLabels: [{worker_id }]} has different label names or a different help string // taskCounter unregistered. - // taskCounterVec not registered: a previously registered descriptor with the same fully-qualified name as Desc{fqName: "worker_pool_completed_tasks_total", help: "Total number of tasks completed.", constLabels: {}, variableLabels: [worker_id]} has different label names or a different help string + // taskCounterVec not registered: a previously registered descriptor with the same fully-qualified name as Desc{fqName: "worker_pool_completed_tasks_total", help: "Total number of tasks completed.", constLabels: {}, variableLabels: [{worker_id }]} has different label names or a different help string // taskCounterVec registered. // Worker initialization failed: inconsistent label cardinality: expected 1 label values but got 2 in []string{"42", "spurious arg"} // notMyCounter is nil. diff --git a/prometheus/gauge.go b/prometheus/gauge.go index 21271a5..f1ea6c7 100644 --- a/prometheus/gauge.go +++ b/prometheus/gauge.go @@ -55,6 +55,18 @@ type Gauge interface { // GaugeOpts is an alias for Opts. See there for doc comments. type GaugeOpts Opts +// GaugeVecOpts bundles the options to create a GaugeVec metric. +// It is mandatory to set GaugeOpts, see there for mandatory fields. VariableLabels +// is optional and can safely be left to its default value. +type GaugeVecOpts struct { + GaugeOpts + + // VariableLabels are used to partition the metric vector by the given set + // of labels. Each label value will be constrained with the optional Contraint + // function, if provided. + VariableLabels ConstrainableLabels +} + // NewGauge creates a new Gauge based on the provided GaugeOpts. // // The returned implementation is optimized for a fast Set method. If you have a @@ -138,16 +150,24 @@ type GaugeVec struct { // NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and // partitioned by the given label names. func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec { - desc := NewDesc( + return V2.NewGaugeVec(GaugeVecOpts{ + GaugeOpts: opts, + VariableLabels: UnconstrainedLabels(labelNames), + }) +} + +// NewGaugeVec creates a new GaugeVec based on the provided GaugeVecOpts. +func (v2) NewGaugeVec(opts GaugeVecOpts) *GaugeVec { + desc := V2.NewDesc( BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), opts.Help, - labelNames, + opts.VariableLabels, opts.ConstLabels, ) return &GaugeVec{ MetricVec: NewMetricVec(desc, func(lvs ...string) Metric { if len(lvs) != len(desc.variableLabels) { - panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs)) + panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.labelNames(), lvs)) } result := &gauge{desc: desc, labelPairs: MakeLabelPairs(desc, lvs)} result.init(result) // Init self-collection. diff --git a/prometheus/histogram.go b/prometheus/histogram.go index 8798184..497a20d 100644 --- a/prometheus/histogram.go +++ b/prometheus/histogram.go @@ -469,6 +469,18 @@ type HistogramOpts struct { NativeHistogramMaxZeroThreshold float64 } +// HistogramVecOpts bundles the options to create a HistogramVec metric. +// It is mandatory to set HistogramOpts, see there for mandatory fields. VariableLabels +// is optional and can safely be left to its default value. +type HistogramVecOpts struct { + HistogramOpts + + // VariableLabels are used to partition the metric vector by the given set + // of labels. Each label value will be constrained with the optional Contraint + // function, if provided. + VariableLabels ConstrainableLabels +} + // NewHistogram creates a new Histogram based on the provided HistogramOpts. It // panics if the buckets in HistogramOpts are not in strictly increasing order. // @@ -489,11 +501,11 @@ func NewHistogram(opts HistogramOpts) Histogram { func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram { if len(desc.variableLabels) != len(labelValues) { - panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues)) + panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.labelNames(), labelValues)) } for _, n := range desc.variableLabels { - if n == bucketLabel { + if n.Name == bucketLabel { panic(errBucketLabelNotAllowed) } } @@ -1030,15 +1042,23 @@ type HistogramVec struct { // NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and // partitioned by the given label names. func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec { - desc := NewDesc( + return V2.NewHistogramVec(HistogramVecOpts{ + HistogramOpts: opts, + VariableLabels: UnconstrainedLabels(labelNames), + }) +} + +// NewHistogramVec creates a new HistogramVec based on the provided HistogramVecOpts. +func (v2) NewHistogramVec(opts HistogramVecOpts) *HistogramVec { + desc := V2.NewDesc( BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), opts.Help, - labelNames, + opts.VariableLabels, opts.ConstLabels, ) return &HistogramVec{ MetricVec: NewMetricVec(desc, func(lvs ...string) Metric { - return newHistogram(desc, opts, lvs...) + return newHistogram(desc, opts.HistogramOpts, lvs...) }), } } diff --git a/prometheus/labels.go b/prometheus/labels.go index c1b8fad..63ff868 100644 --- a/prometheus/labels.go +++ b/prometheus/labels.go @@ -32,6 +32,78 @@ import ( // create a Desc. type Labels map[string]string +// ConstrainedLabels represents a label name and its constrain function +// to normalize label values. This type is commonly used when constructing +// metric vector Collectors. +type ConstrainedLabel struct { + Name string + Constraint func(string) string +} + +func (cl ConstrainedLabel) Constrain(v string) string { + if cl.Constraint == nil { + return v + } + return cl.Constraint(v) +} + +// ConstrainableLabels is an interface that allows creating of labels that can +// be optionally constrained. +// +// prometheus.V2().NewCounterVec(CounterVecOpts{ +// CounterOpts: {...}, // Usual CounterOpts fields +// VariableLabels: []ConstrainedLabels{ +// {Name: "A"}, +// {Name: "B", Constraint: func(v string) string { ... }}, +// }, +// }) +type ConstrainableLabels interface { + constrainedLabels() ConstrainedLabels + labelNames() []string +} + +// ConstrainedLabels represents a collection of label name -> constrain function +// to normalize label values. This type is commonly used when constructing +// metric vector Collectors. +type ConstrainedLabels []ConstrainedLabel + +func (cls ConstrainedLabels) constrainedLabels() ConstrainedLabels { + return cls +} + +func (cls ConstrainedLabels) labelNames() []string { + names := make([]string, len(cls)) + for i, label := range cls { + names[i] = label.Name + } + return names +} + +// UnconstrainedLabels represents collection of label without any constraint on +// their value. Thus, it is simply a collection of label names. +// +// UnconstrainedLabels([]string{ "A", "B" }) +// +// is equivalent to +// +// ConstrainedLabels { +// { Name: "A" }, +// { Name: "B" }, +// } +type UnconstrainedLabels []string + +func (uls UnconstrainedLabels) constrainedLabels() ConstrainedLabels { + constrainedLabels := make([]ConstrainedLabel, len(uls)) + for i, l := range uls { + constrainedLabels[i] = ConstrainedLabel{Name: l} + } + return constrainedLabels +} + +func (uls UnconstrainedLabels) labelNames() []string { + return uls +} + // reservedLabelPrefix is a prefix which is not legal in user-supplied // label names. const reservedLabelPrefix = "__" diff --git a/prometheus/registry.go b/prometheus/registry.go index 09e34d3..f5afeb0 100644 --- a/prometheus/registry.go +++ b/prometheus/registry.go @@ -962,7 +962,7 @@ func checkDescConsistency( copy(lpsFromDesc, desc.constLabelPairs) for _, l := range desc.variableLabels { lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{ - Name: proto.String(l), + Name: proto.String(l.Name), }) } if len(lpsFromDesc) != len(dtoMetric.Label) { diff --git a/prometheus/summary.go b/prometheus/summary.go index 7bc448a..87f27cc 100644 --- a/prometheus/summary.go +++ b/prometheus/summary.go @@ -148,6 +148,18 @@ type SummaryOpts struct { BufCap uint32 } +// SummaryVecOpts bundles the options to create a SummaryVec metric. +// It is mandatory to set SummaryOpts, see there for mandatory fields. VariableLabels +// is optional and can safely be left to its default value. +type SummaryVecOpts struct { + SummaryOpts + + // VariableLabels are used to partition the metric vector by the given set + // of labels. Each label value will be constrained with the optional Contraint + // function, if provided. + VariableLabels ConstrainableLabels +} + // Problem with the sliding-window decay algorithm... The Merge method of // perk/quantile is actually not working as advertised - and it might be // unfixable, as the underlying algorithm is apparently not capable of merging @@ -178,11 +190,11 @@ func NewSummary(opts SummaryOpts) Summary { func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary { if len(desc.variableLabels) != len(labelValues) { - panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues)) + panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.labelNames(), labelValues)) } for _, n := range desc.variableLabels { - if n == quantileLabel { + if n.Name == quantileLabel { panic(errQuantileLabelNotAllowed) } } @@ -530,20 +542,28 @@ type SummaryVec struct { // it is handled by the Prometheus server internally, “quantile” is an illegal // label name. NewSummaryVec will panic if this label name is used. func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec { - for _, ln := range labelNames { + return V2.NewSummaryVec(SummaryVecOpts{ + SummaryOpts: opts, + VariableLabels: UnconstrainedLabels(labelNames), + }) +} + +// NewSummaryVec creates a new SummaryVec based on the provided SummaryVecOpts. +func (v2) NewSummaryVec(opts SummaryVecOpts) *SummaryVec { + for _, ln := range opts.VariableLabels.labelNames() { if ln == quantileLabel { panic(errQuantileLabelNotAllowed) } } - desc := NewDesc( + desc := V2.NewDesc( BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), opts.Help, - labelNames, + opts.VariableLabels, opts.ConstLabels, ) return &SummaryVec{ MetricVec: NewMetricVec(desc, func(lvs ...string) Metric { - return newSummary(desc, opts, lvs...) + return newSummary(desc, opts.SummaryOpts, lvs...) }), } } diff --git a/prometheus/value.go b/prometheus/value.go index 2d3abc1..a1ec937 100644 --- a/prometheus/value.go +++ b/prometheus/value.go @@ -188,9 +188,9 @@ func MakeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair { return desc.constLabelPairs } labelPairs := make([]*dto.LabelPair, 0, totalLen) - for i, n := range desc.variableLabels { + for i, l := range desc.variableLabels { labelPairs = append(labelPairs, &dto.LabelPair{ - Name: proto.String(n), + Name: proto.String(l.Name), Value: proto.String(labelValues[i]), }) } diff --git a/prometheus/vec.go b/prometheus/vec.go index 7ae3225..386fb2d 100644 --- a/prometheus/vec.go +++ b/prometheus/vec.go @@ -72,6 +72,7 @@ func NewMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec { // with a performance overhead (for creating and processing the Labels map). // See also the CounterVec example. func (m *MetricVec) DeleteLabelValues(lvs ...string) bool { + lvs = constrainLabelValues(m.desc, lvs, m.curry) h, err := m.hashLabelValues(lvs) if err != nil { return false @@ -91,6 +92,7 @@ func (m *MetricVec) DeleteLabelValues(lvs ...string) bool { // This method is used for the same purpose as DeleteLabelValues(...string). See // there for pros and cons of the two methods. func (m *MetricVec) Delete(labels Labels) bool { + labels = constrainLabels(m.desc, labels) h, err := m.hashLabels(labels) if err != nil { return false @@ -106,6 +108,7 @@ func (m *MetricVec) Delete(labels Labels) bool { // Note that curried labels will never be matched if deleting from the curried vector. // To match curried labels with DeletePartialMatch, it must be called on the base vector. func (m *MetricVec) DeletePartialMatch(labels Labels) int { + labels = constrainLabels(m.desc, labels) return m.metricMap.deleteByLabels(labels, m.curry) } @@ -145,10 +148,10 @@ func (m *MetricVec) CurryWith(labels Labels) (*MetricVec, error) { iCurry int ) for i, label := range m.desc.variableLabels { - val, ok := labels[label] + val, ok := labels[label.Name] if iCurry < len(oldCurry) && oldCurry[iCurry].index == i { if ok { - return nil, fmt.Errorf("label name %q is already curried", label) + return nil, fmt.Errorf("label name %q is already curried", label.Name) } newCurry = append(newCurry, oldCurry[iCurry]) iCurry++ @@ -156,7 +159,7 @@ func (m *MetricVec) CurryWith(labels Labels) (*MetricVec, error) { if !ok { continue // Label stays uncurried. } - newCurry = append(newCurry, curriedLabelValue{i, val}) + newCurry = append(newCurry, curriedLabelValue{i, label.Constrain(val)}) } } if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 { @@ -199,6 +202,7 @@ func (m *MetricVec) CurryWith(labels Labels) (*MetricVec, error) { // a wrapper around MetricVec, implementing a vector for a specific Metric // implementation, for example GaugeVec. func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) { + lvs = constrainLabelValues(m.desc, lvs, m.curry) h, err := m.hashLabelValues(lvs) if err != nil { return nil, err @@ -224,6 +228,7 @@ func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) { // around MetricVec, implementing a vector for a specific Metric implementation, // for example GaugeVec. func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) { + labels = constrainLabels(m.desc, labels) h, err := m.hashLabels(labels) if err != nil { return nil, err @@ -266,16 +271,16 @@ func (m *MetricVec) hashLabels(labels Labels) (uint64, error) { iCurry int ) for i, label := range m.desc.variableLabels { - val, ok := labels[label] + val, ok := labels[label.Name] if iCurry < len(curry) && curry[iCurry].index == i { if ok { - return 0, fmt.Errorf("label name %q is already curried", label) + return 0, fmt.Errorf("label name %q is already curried", label.Name) } h = m.hashAdd(h, curry[iCurry].value) iCurry++ } else { if !ok { - return 0, fmt.Errorf("label name %q missing in label map", label) + return 0, fmt.Errorf("label name %q missing in label map", label.Name) } h = m.hashAdd(h, val) } @@ -453,7 +458,7 @@ func valueMatchesVariableOrCurriedValue(targetValue string, index int, values [] func matchPartialLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool { for l, v := range labels { // Check if the target label exists in our metrics and get the index. - varLabelIndex, validLabel := indexOf(l, desc.variableLabels) + varLabelIndex, validLabel := indexOf(l, desc.variableLabels.labelNames()) if validLabel { // Check the value of that label against the target value. // We don't consider curried values in partial matches. @@ -605,7 +610,7 @@ func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabe iCurry++ continue } - if values[i] != labels[k] { + if values[i] != labels[k.Name] { return false } } @@ -621,7 +626,7 @@ func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) [] iCurry++ continue } - labelValues[i] = labels[k] + labelValues[i] = labels[k.Name] } return labelValues } @@ -640,3 +645,34 @@ func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string { } return labelValues } + +func constrainLabels(desc *Desc, labels Labels) Labels { + constrainedValues := make(Labels, len(labels)) + for l, v := range labels { + if i, ok := indexOf(l, desc.variableLabels.labelNames()); ok { + constrainedValues[l] = desc.variableLabels[i].Constrain(v) + continue + } + constrainedValues[l] = v + } + return constrainedValues +} + +func constrainLabelValues(desc *Desc, lvs []string, curry []curriedLabelValue) []string { + constrainedValues := make([]string, len(lvs)) + var iCurry, iLVs int + for i := 0; i < len(lvs)+len(curry); i++ { + if iCurry < len(curry) && curry[iCurry].index == i { + iCurry++ + continue + } + + if i < len(desc.variableLabels) { + constrainedValues[iLVs] = desc.variableLabels[i].Constrain(lvs[iLVs]) + } else { + constrainedValues[iLVs] = lvs[iLVs] + } + iLVs++ + } + return constrainedValues +} diff --git a/prometheus/vec_test.go b/prometheus/vec_test.go index 6bc2afe..63f52af 100644 --- a/prometheus/vec_test.go +++ b/prometheus/vec_test.go @@ -15,6 +15,7 @@ package prometheus import ( "fmt" + "reflect" "testing" dto "github.com/prometheus/client_model/go" @@ -44,6 +45,20 @@ func TestDeleteWithCollisions(t *testing.T) { testDelete(t, vec) } +func TestDeleteWithConstraints(t *testing.T) { + vec := V2.NewGaugeVec(GaugeVecOpts{ + GaugeOpts{ + Name: "test", + Help: "helpless", + }, + ConstrainedLabels{ + {Name: "l1"}, + {Name: "l2", Constraint: func(s string) string { return "x" + s }}, + }, + }) + testDelete(t, vec) +} + func testDelete(t *testing.T, vec *GaugeVec) { if got, want := vec.Delete(Labels{"l1": "v1", "l2": "v2"}), false; got != want { t.Errorf("got %v, want %v", got, want) @@ -98,6 +113,20 @@ func TestDeleteLabelValuesWithCollisions(t *testing.T) { testDeleteLabelValues(t, vec) } +func TestDeleteLabelValuesWithConstraints(t *testing.T) { + vec := V2.NewGaugeVec(GaugeVecOpts{ + GaugeOpts{ + Name: "test", + Help: "helpless", + }, + ConstrainedLabels{ + {Name: "l1"}, + {Name: "l2", Constraint: func(s string) string { return "x" + s }}, + }, + }) + testDeleteLabelValues(t, vec) +} + func testDeleteLabelValues(t *testing.T, vec *GaugeVec) { if got, want := vec.DeleteLabelValues("v1", "v2"), false; got != want { t.Errorf("got %v, want %v", got, want) @@ -126,14 +155,32 @@ func testDeleteLabelValues(t *testing.T, vec *GaugeVec) { } func TestDeletePartialMatch(t *testing.T) { - baseVec := NewGaugeVec( + vec := NewGaugeVec( GaugeOpts{ Name: "test", Help: "helpless", }, []string{"l1", "l2", "l3"}, ) + testDeletePartialMatch(t, vec) +} +func TestDeletePartialMatchWithConstraints(t *testing.T) { + vec := V2.NewGaugeVec(GaugeVecOpts{ + GaugeOpts{ + Name: "test", + Help: "helpless", + }, + ConstrainedLabels{ + {Name: "l1"}, + {Name: "l2", Constraint: func(s string) string { return "x" + s }}, + {Name: "l3"}, + }, + }) + testDeletePartialMatch(t, vec) +} + +func testDeletePartialMatch(t *testing.T, baseVec *GaugeVec) { assertNoMetric := func(t *testing.T) { if n := len(baseVec.metricMap.metrics); n != 0 { t.Error("expected no metrics, got", n) @@ -293,6 +340,78 @@ func testMetricVec(t *testing.T, vec *GaugeVec) { } } +func TestMetricVecWithConstraints(t *testing.T) { + constraint := func(s string) string { return "x" + s } + vec := V2.NewGaugeVec(GaugeVecOpts{ + GaugeOpts{ + Name: "test", + Help: "helpless", + }, + ConstrainedLabels{ + {Name: "l1"}, + {Name: "l2", Constraint: constraint}, + }, + }) + testConstrainedMetricVec(t, vec, constraint) +} + +func testConstrainedMetricVec(t *testing.T, vec *GaugeVec, constrain func(string) string) { + vec.Reset() // Actually test Reset now! + + var pair [2]string + // Keep track of metrics. + expected := map[[2]string]int{} + + for i := 0; i < 1000; i++ { + pair[0], pair[1] = fmt.Sprint(i%4), fmt.Sprint(i%5) // Varying combinations multiples. + expected[[2]string{pair[0], constrain(pair[1])}]++ + vec.WithLabelValues(pair[0], pair[1]).Inc() + + expected[[2]string{"v1", constrain("v2")}]++ + vec.WithLabelValues("v1", "v2").Inc() + } + + var total int + for _, metrics := range vec.metricMap.metrics { + for _, metric := range metrics { + total++ + copy(pair[:], metric.values) + + var metricOut dto.Metric + if err := metric.metric.Write(&metricOut); err != nil { + t.Fatal(err) + } + actual := *metricOut.Gauge.Value + + var actualPair [2]string + for i, label := range metricOut.Label { + actualPair[i] = *label.Value + } + + // Test output pair against metric.values to ensure we've selected + // the right one. We check this to ensure the below check means + // anything at all. + if actualPair != pair { + t.Fatalf("unexpected pair association in metric map: %v != %v", actualPair, pair) + } + + if actual != float64(expected[pair]) { + t.Fatalf("incorrect counter value for %v: %v != %v", pair, actual, expected[pair]) + } + } + } + + if total != len(expected) { + t.Fatalf("unexpected number of metrics: %v != %v", total, len(expected)) + } + + vec.Reset() + + if len(vec.metricMap.metrics) > 0 { + t.Fatalf("reset failed") + } +} + func TestCounterVecEndToEndWithCollision(t *testing.T) { vec := NewCounterVec( CounterOpts{ @@ -350,6 +469,39 @@ func TestCurryVecWithCollisions(t *testing.T) { testCurryVec(t, vec) } +func TestCurryVecWithConstraints(t *testing.T) { + constraint := func(s string) string { return "x" + s } + t.Run("constrainedLabels overlap variableLabels", func(t *testing.T) { + vec := V2.NewCounterVec(CounterVecOpts{ + CounterOpts{ + Name: "test", + Help: "helpless", + }, + ConstrainedLabels{ + {Name: "one"}, + {Name: "two"}, + {Name: "three", Constraint: constraint}, + }, + }) + testCurryVec(t, vec) + }) + t.Run("constrainedLabels reducing cardinality", func(t *testing.T) { + constraint := func(s string) string { return "x" } + vec := V2.NewCounterVec(CounterVecOpts{ + CounterOpts{ + Name: "test", + Help: "helpless", + }, + ConstrainedLabels{ + {Name: "one"}, + {Name: "two"}, + {Name: "three", Constraint: constraint}, + }, + }) + testConstrainedCurryVec(t, vec, constraint) + }) +} + func testCurryVec(t *testing.T, vec *CounterVec) { assertMetrics := func(t *testing.T) { n := 0 @@ -547,6 +699,211 @@ func testCurryVec(t *testing.T, vec *CounterVec) { }) } +func testConstrainedCurryVec(t *testing.T, vec *CounterVec, constraint func(string) string) { + assertMetrics := func(t *testing.T) { + n := 0 + for _, m := range vec.metricMap.metrics { + n += len(m) + } + if n != 2 { + t.Error("expected two metrics, got", n) + } + m := &dto.Metric{} + c1, err := vec.GetMetricWithLabelValues("1", "2", "3") + if err != nil { + t.Fatal("unexpected error getting metric:", err) + } + c1.Write(m) + if want, got := 1., m.GetCounter().GetValue(); want != got { + t.Errorf("want %f as counter value, got %f", want, got) + } + values := map[string]string{} + for _, label := range m.Label { + values[*label.Name] = *label.Value + } + if want, got := map[string]string{"one": "1", "two": "2", "three": constraint("3")}, values; !reflect.DeepEqual(want, got) { + t.Errorf("want %v as label values, got %v", want, got) + } + m.Reset() + c2, err := vec.GetMetricWithLabelValues("11", "22", "33") + if err != nil { + t.Fatal("unexpected error getting metric:", err) + } + c2.Write(m) + if want, got := 1., m.GetCounter().GetValue(); want != got { + t.Errorf("want %f as counter value, got %f", want, got) + } + values = map[string]string{} + for _, label := range m.Label { + values[*label.Name] = *label.Value + } + if want, got := map[string]string{"one": "11", "two": "22", "three": constraint("33")}, values; !reflect.DeepEqual(want, got) { + t.Errorf("want %v as label values, got %v", want, got) + } + } + + assertNoMetric := func(t *testing.T) { + if n := len(vec.metricMap.metrics); n != 0 { + t.Error("expected no metrics, got", n) + } + } + + t.Run("zero labels", func(t *testing.T) { + c1 := vec.MustCurryWith(nil) + c2 := vec.MustCurryWith(nil) + c1.WithLabelValues("1", "2", "3").Inc() + c2.With(Labels{"one": "11", "two": "22", "three": "33"}).Inc() + assertMetrics(t) + if !c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) { + t.Error("deletion failed") + } + if !c2.DeleteLabelValues("11", "22", "33") { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("first label", func(t *testing.T) { + c1 := vec.MustCurryWith(Labels{"one": "1"}) + c2 := vec.MustCurryWith(Labels{"one": "11"}) + c1.WithLabelValues("2", "3").Inc() + c2.With(Labels{"two": "22", "three": "33"}).Inc() + assertMetrics(t) + if c1.Delete(Labels{"two": "22", "three": "33"}) { + t.Error("deletion unexpectedly succeeded") + } + if c2.DeleteLabelValues("2", "3") { + t.Error("deletion unexpectedly succeeded") + } + if !c1.Delete(Labels{"two": "2", "three": "3"}) { + t.Error("deletion failed") + } + if !c2.DeleteLabelValues("22", "33") { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("middle label", func(t *testing.T) { + c1 := vec.MustCurryWith(Labels{"two": "2"}) + c2 := vec.MustCurryWith(Labels{"two": "22"}) + c1.WithLabelValues("1", "3").Inc() + c2.With(Labels{"one": "11", "three": "33"}).Inc() + assertMetrics(t) + if c1.Delete(Labels{"one": "11", "three": "33"}) { + t.Error("deletion unexpectedly succeeded") + } + if c2.DeleteLabelValues("1", "3") { + t.Error("deletion unexpectedly succeeded") + } + if !c1.Delete(Labels{"one": "1", "three": "3"}) { + t.Error("deletion failed") + } + if !c2.DeleteLabelValues("11", "33") { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("last label (constrained to static value)", func(t *testing.T) { + c1 := vec.MustCurryWith(Labels{"three": "3"}) + c2 := vec.MustCurryWith(Labels{"three": "33"}) + c1.WithLabelValues("1", "2").Inc() + c2.With(Labels{"one": "11", "two": "22"}).Inc() + assertMetrics(t) + if !c1.Delete(Labels{"two": "22", "one": "11"}) { + t.Error("deletion failed") + } + if !c2.DeleteLabelValues("1", "2") { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("two labels", func(t *testing.T) { + c1 := vec.MustCurryWith(Labels{"three": "3", "one": "1"}) + c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11"}) + c1.WithLabelValues("2").Inc() + c2.With(Labels{"two": "22"}).Inc() + assertMetrics(t) + if c1.Delete(Labels{"two": "22"}) { + t.Error("deletion unexpectedly succeeded") + } + if c2.DeleteLabelValues("2") { + t.Error("deletion unexpectedly succeeded") + } + if !c1.Delete(Labels{"two": "2"}) { + t.Error("deletion failed") + } + if !c2.DeleteLabelValues("22") { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("all labels", func(t *testing.T) { + c1 := vec.MustCurryWith(Labels{"three": "3", "two": "2", "one": "1"}) + c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11", "two": "22"}) + c1.WithLabelValues().Inc() + c2.With(nil).Inc() + assertMetrics(t) + if !c1.Delete(Labels{}) { + t.Error("deletion failed") + } + if !c2.DeleteLabelValues() { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("double curry", func(t *testing.T) { + c1 := vec.MustCurryWith(Labels{"three": "3"}).MustCurryWith(Labels{"one": "1"}) + c2 := vec.MustCurryWith(Labels{"three": "33"}).MustCurryWith(Labels{"one": "11"}) + c1.WithLabelValues("2").Inc() + c2.With(Labels{"two": "22"}).Inc() + assertMetrics(t) + if c1.Delete(Labels{"two": "22"}) { + t.Error("deletion unexpectedly succeeded") + } + if c2.DeleteLabelValues("2") { + t.Error("deletion unexpectedly succeeded") + } + if !c1.Delete(Labels{"two": "2"}) { + t.Error("deletion failed") + } + if !c2.DeleteLabelValues("22") { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("use already curried label", func(t *testing.T) { + c1 := vec.MustCurryWith(Labels{"three": "3"}) + if _, err := c1.GetMetricWithLabelValues("1", "2", "3"); err == nil { + t.Error("expected error when using already curried label") + } + if _, err := c1.GetMetricWith(Labels{"one": "1", "two": "2", "three": "3"}); err == nil { + t.Error("expected error when using already curried label") + } + assertNoMetric(t) + c1.WithLabelValues("1", "2").Inc() + if c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) { + t.Error("deletion unexpectedly succeeded") + } + if !c1.Delete(Labels{"one": "1", "two": "2"}) { + t.Error("deletion failed") + } + assertNoMetric(t) + }) + t.Run("curry already curried label", func(t *testing.T) { + if _, err := vec.MustCurryWith(Labels{"three": "3"}).CurryWith(Labels{"three": "33"}); err == nil { + t.Error("currying unexpectedly succeeded") + } else if err.Error() != `label name "three" is already curried` { + t.Error("currying returned unexpected error:", err) + } + }) + t.Run("unknown label", func(t *testing.T) { + if _, err := vec.CurryWith(Labels{"foo": "bar"}); err == nil { + t.Error("currying unexpectedly succeeded") + } else if err.Error() != "1 unknown label(s) found during currying" { + t.Error("currying returned unexpected error:", err) + } + }) +} + func BenchmarkMetricVecWithLabelValuesBasic(b *testing.B) { benchmarkMetricVecWithLabelValues(b, map[string][]string{ "l1": {"onevalue"}, diff --git a/prometheus/vnext.go b/prometheus/vnext.go new file mode 100644 index 0000000..42bc3a8 --- /dev/null +++ b/prometheus/vnext.go @@ -0,0 +1,23 @@ +// Copyright 2022 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +type v2 struct{} + +// V2 is a struct that can be referenced to access experimental API that might +// be present in v2 of client golang someday. It offers extended functionality +// of v1 with slightly changed API. It is acceptable to use some pieces from v1 +// and e.g `prometheus.NewGauge` and some from v2 e.g. `prometheus.V2.NewDesc` +// in the same codebase. +var V2 = v2{} diff --git a/prometheus/wrap.go b/prometheus/wrap.go index 1498ee1..a51408b 100644 --- a/prometheus/wrap.go +++ b/prometheus/wrap.go @@ -206,7 +206,7 @@ func wrapDesc(desc *Desc, prefix string, labels Labels) *Desc { constLabels[ln] = lv } // NewDesc will do remaining validations. - newDesc := NewDesc(prefix+desc.fqName, desc.help, desc.variableLabels, constLabels) + newDesc := V2.NewDesc(prefix+desc.fqName, desc.help, desc.variableLabels, constLabels) // Propagate errors if there was any. This will override any errer // created by NewDesc above, i.e. earlier errors get precedence. if desc.err != nil {