temp commit

vendor/github.com/prometheus/client_golang/api/prometheus/v1/api.go

@@ -20,6 +20,7 @@ package v1
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"strconv"
@@ -40,6 +41,7 @@ const (
 	epLabelValues     = apiPrefix + "/label/:name/values"
 	epSeries          = apiPrefix + "/series"
 	epTargets         = apiPrefix + "/targets"
+	epRules           = apiPrefix + "/rules"
 	epSnapshot        = apiPrefix + "/admin/tsdb/snapshot"
 	epDeleteSeries    = apiPrefix + "/admin/tsdb/delete_series"
 	epCleanTombstones = apiPrefix + "/admin/tsdb/clean_tombstones"
@@ -47,13 +49,27 @@ const (
 	epFlags           = apiPrefix + "/status/flags"
 )
 
+// AlertState models the state of an alert.
+type AlertState string
+
 // ErrorType models the different API error types.
 type ErrorType string
 
 // HealthStatus models the health status of a scrape target.
 type HealthStatus string
 
+// RuleType models the type of a rule.
+type RuleType string
+
+// RuleHealth models the health status of a rule.
+type RuleHealth string
+
 const (
+	// Possible values for AlertState.
+	AlertStateFiring   AlertState = "firing"
+	AlertStateInactive AlertState = "inactive"
+	AlertStatePending  AlertState = "pending"
+
 	// Possible values for ErrorType.
 	ErrBadData     ErrorType = "bad_data"
 	ErrTimeout     ErrorType = "timeout"
@@ -67,6 +83,15 @@ const (
 	HealthGood    HealthStatus = "up"
 	HealthUnknown HealthStatus = "unknown"
 	HealthBad     HealthStatus = "down"
+
+	// Possible values for RuleType.
+	RuleTypeRecording RuleType = "recording"
+	RuleTypeAlerting  RuleType = "alerting"
+
+	// Possible values for RuleHealth.
+	RuleHealthGood    = "ok"
+	RuleHealthUnknown = "unknown"
+	RuleHealthBad     = "err"
 )
 
 // Error is an error returned by the API.
@@ -111,6 +136,8 @@ type API interface {
 	// Snapshot creates a snapshot of all current data into snapshots/<datetime>-<rand>
 	// under the TSDB's data directory and returns the directory as response.
 	Snapshot(ctx context.Context, skipHead bool) (SnapshotResult, error)
+	// Rules returns a list of alerting and recording rules that are currently loaded.
+	Rules(ctx context.Context) (RulesResult, error)
 	// Targets returns an overview of the current state of the Prometheus target discovery.
 	Targets(ctx context.Context) (TargetsResult, error)
 }
@@ -139,6 +166,63 @@ type SnapshotResult struct {
 	Name string `json:"name"`
 }
 
+// RulesResult contains the result from querying the rules endpoint.
+type RulesResult struct {
+	Groups []RuleGroup `json:"groups"`
+}
+
+// RuleGroup models a rule group that contains a set of recording and alerting rules.
+type RuleGroup struct {
+	Name     string  `json:"name"`
+	File     string  `json:"file"`
+	Interval float64 `json:"interval"`
+	Rules    Rules   `json:"rules"`
+}
+
+// Recording and alerting rules are stored in the same slice to preserve the order
+// that rules are returned in by the API.
+//
+// Rule types can be determined using a type switch:
+//   switch v := rule.(type) {
+//   case RecordingRule:
+//   	fmt.Print("got a recording rule")
+//   case AlertingRule:
+//   	fmt.Print("got a alerting rule")
+//   default:
+//   	fmt.Printf("unknown rule type %s", v)
+//   }
+type Rules []interface{}
+
+// AlertingRule models a alerting rule.
+type AlertingRule struct {
+	Name        string         `json:"name"`
+	Query       string         `json:"query"`
+	Duration    float64        `json:"duration"`
+	Labels      model.LabelSet `json:"labels"`
+	Annotations model.LabelSet `json:"annotations"`
+	Alerts      []*Alert       `json:"alerts"`
+	Health      RuleHealth     `json:"health"`
+	LastError   string         `json:"lastError,omitempty"`
+}
+
+// RecordingRule models a recording rule.
+type RecordingRule struct {
+	Name      string         `json:"name"`
+	Query     string         `json:"query"`
+	Labels    model.LabelSet `json:"labels,omitempty"`
+	Health    RuleHealth     `json:"health"`
+	LastError string         `json:"lastError,omitempty"`
+}
+
+// Alert models an active alert.
+type Alert struct {
+	ActiveAt    time.Time `json:"activeAt"`
+	Annotations model.LabelSet
+	Labels      model.LabelSet
+	State       AlertState
+	Value       float64
+}
+
 // TargetsResult contains the result from querying the targets endpoint.
 type TargetsResult struct {
 	Active  []ActiveTarget  `json:"activeTargets"`
@@ -147,17 +231,17 @@ type TargetsResult struct {
 
 // ActiveTarget models an active Prometheus scrape target.
 type ActiveTarget struct {
-	DiscoveredLabels model.LabelSet `json:"discoveredLabels"`
-	Labels           model.LabelSet `json:"labels"`
-	ScrapeURL        string         `json:"scrapeUrl"`
-	LastError        string         `json:"lastError"`
-	LastScrape       time.Time      `json:"lastScrape"`
-	Health           HealthStatus   `json:"health"`
+	DiscoveredLabels map[string]string `json:"discoveredLabels"`
+	Labels           model.LabelSet    `json:"labels"`
+	ScrapeURL        string            `json:"scrapeUrl"`
+	LastError        string            `json:"lastError"`
+	LastScrape       time.Time         `json:"lastScrape"`
+	Health           HealthStatus      `json:"health"`
 }
 
 // DroppedTarget models a dropped Prometheus scrape target.
 type DroppedTarget struct {
-	DiscoveredLabels model.LabelSet `json:"discoveredLabels"`
+	DiscoveredLabels map[string]string `json:"discoveredLabels"`
 }
 
 // queryResult contains result data for a query.
@@ -169,6 +253,111 @@ type queryResult struct {
 	v model.Value
 }
 
+func (rg *RuleGroup) UnmarshalJSON(b []byte) error {
+	v := struct {
+		Name     string            `json:"name"`
+		File     string            `json:"file"`
+		Interval float64           `json:"interval"`
+		Rules    []json.RawMessage `json:"rules"`
+	}{}
+
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+
+	rg.Name = v.Name
+	rg.File = v.File
+	rg.Interval = v.Interval
+
+	for _, rule := range v.Rules {
+		alertingRule := AlertingRule{}
+		if err := json.Unmarshal(rule, &alertingRule); err == nil {
+			rg.Rules = append(rg.Rules, alertingRule)
+			continue
+		}
+		recordingRule := RecordingRule{}
+		if err := json.Unmarshal(rule, &recordingRule); err == nil {
+			rg.Rules = append(rg.Rules, recordingRule)
+			continue
+		}
+		return errors.New("failed to decode JSON into an alerting or recording rule")
+	}
+
+	return nil
+}
+
+func (r *AlertingRule) UnmarshalJSON(b []byte) error {
+	v := struct {
+		Type string `json:"type"`
+	}{}
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+	if v.Type == "" {
+		return errors.New("type field not present in rule")
+	}
+	if v.Type != string(RuleTypeAlerting) {
+		return fmt.Errorf("expected rule of type %s but got %s", string(RuleTypeAlerting), v.Type)
+	}
+
+	rule := struct {
+		Name        string         `json:"name"`
+		Query       string         `json:"query"`
+		Duration    float64        `json:"duration"`
+		Labels      model.LabelSet `json:"labels"`
+		Annotations model.LabelSet `json:"annotations"`
+		Alerts      []*Alert       `json:"alerts"`
+		Health      RuleHealth     `json:"health"`
+		LastError   string         `json:"lastError,omitempty"`
+	}{}
+	if err := json.Unmarshal(b, &rule); err != nil {
+		return err
+	}
+	r.Health = rule.Health
+	r.Annotations = rule.Annotations
+	r.Name = rule.Name
+	r.Query = rule.Query
+	r.Alerts = rule.Alerts
+	r.Duration = rule.Duration
+	r.Labels = rule.Labels
+	r.LastError = rule.LastError
+
+	return nil
+}
+
+func (r *RecordingRule) UnmarshalJSON(b []byte) error {
+	v := struct {
+		Type string `json:"type"`
+	}{}
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+	if v.Type == "" {
+		return errors.New("type field not present in rule")
+	}
+	if v.Type != string(RuleTypeRecording) {
+		return fmt.Errorf("expected rule of type %s but got %s", string(RuleTypeRecording), v.Type)
+	}
+
+	rule := struct {
+		Name      string         `json:"name"`
+		Query     string         `json:"query"`
+		Labels    model.LabelSet `json:"labels,omitempty"`
+		Health    RuleHealth     `json:"health"`
+		LastError string         `json:"lastError,omitempty"`
+	}{}
+	if err := json.Unmarshal(b, &rule); err != nil {
+		return err
+	}
+	r.Health = rule.Health
+	r.Labels = rule.Labels
+	r.Name = rule.Name
+	r.LastError = rule.LastError
+	r.Query = rule.Query
+
+	return nil
+}
+
 func (qr *queryResult) UnmarshalJSON(b []byte) error {
 	v := struct {
 		Type   model.ValueType `json:"resultType"`
@@ -427,6 +616,24 @@ func (h *httpAPI) Snapshot(ctx context.Context, skipHead bool) (SnapshotResult,
 	return res, err
 }
 
+func (h *httpAPI) Rules(ctx context.Context) (RulesResult, error) {
+	u := h.client.URL(epRules, nil)
+
+	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
+	if err != nil {
+		return RulesResult{}, err
+	}
+
+	_, body, err := h.client.Do(ctx, req)
+	if err != nil {
+		return RulesResult{}, err
+	}
+
+	var res RulesResult
+	err = json.Unmarshal(body, &res)
+	return res, err
+}
+
 func (h *httpAPI) Targets(ctx context.Context) (TargetsResult, error) {
 	u := h.client.URL(epTargets, nil)
 

vendor/github.com/prometheus/client_golang/prometheus/collector.go

@@ -79,7 +79,7 @@ type Collector interface {
 // of the Describe method. If a Collector sometimes collects no metrics at all
 // (for example vectors like CounterVec, GaugeVec, etc., which only collect
 // metrics after a metric with a fully specified label set has been accessed),
-// it might even get registered as an unchecked Collecter (cf. the Register
+// it might even get registered as an unchecked Collector (cf. the Register
 // method of the Registerer interface). Hence, only use this shortcut
 // implementation of Describe if you are certain to fulfill the contract.
 //

vendor/github.com/prometheus/client_golang/prometheus/doc.go

@@ -122,13 +122,13 @@
 // the Collect method. The Describe method has to return separate Desc
 // instances, representative of the “throw-away” metrics to be created later.
 // NewDesc comes in handy to create those Desc instances. Alternatively, you
-// could return no Desc at all, which will marke the Collector “unchecked”.  No
-// checks are porformed at registration time, but metric consistency will still
+// could return no Desc at all, which will mark the Collector “unchecked”.  No
+// checks are performed at registration time, but metric consistency will still
 // be ensured at scrape time, i.e. any inconsistencies will lead to scrape
 // errors. Thus, with unchecked Collectors, the responsibility to not collect
 // metrics that lead to inconsistencies in the total scrape result lies with the
 // implementer of the Collector. While this is not a desirable state, it is
-// sometimes necessary. The typical use case is a situatios where the exact
+// sometimes necessary. The typical use case is a situation where the exact
 // metrics to be returned by a Collector cannot be predicted at registration
 // time, but the implementer has sufficient knowledge of the whole system to
 // guarantee metric consistency.

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -204,8 +204,8 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 			}
 		}
 	}
-	// Finally we know the final length of h.upperBounds and can make counts
-	// for both states:
+	// Finally we know the final length of h.upperBounds and can make buckets
+	// for both counts:
 	h.counts[0].buckets = make([]uint64, len(h.upperBounds))
 	h.counts[1].buckets = make([]uint64, len(h.upperBounds))
 

vendor/github.com/prometheus/client_golang/prometheus/http.go

@@ -34,7 +34,6 @@ import (
 
 const (
 	contentTypeHeader     = "Content-Type"
-	contentLengthHeader   = "Content-Length"
 	contentEncodingHeader = "Content-Encoding"
 	acceptEncodingHeader  = "Accept-Encoding"
 )

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -38,7 +38,6 @@ type delegator interface {
 type responseWriterDelegator struct {
 	http.ResponseWriter
 
-	handler, method    string
 	status             int
 	written            int64
 	wroteHeader        bool

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -47,7 +47,6 @@ import (
 
 const (
 	contentTypeHeader     = "Content-Type"
-	contentLengthHeader   = "Content-Length"
 	contentEncodingHeader = "Content-Encoding"
 	acceptEncodingHeader  = "Accept-Encoding"
 )

vendor/github.com/prometheus/client_golang/prometheus/registry.go

@@ -680,7 +680,7 @@ func processMetric(
 // Gatherers is a slice of Gatherer instances that implements the Gatherer
 // interface itself. Its Gather method calls Gather on all Gatherers in the
 // slice in order and returns the merged results. Errors returned from the
-// Gather calles are all returned in a flattened MultiError. Duplicate and
+// Gather calls are all returned in a flattened MultiError. Duplicate and
 // inconsistent Metrics are skipped (first occurrence in slice order wins) and
 // reported in the returned error.
 //

vendor/github.com/prometheus/client_golang/prometheus/summary.go

@@ -16,8 +16,10 @@ package prometheus
 import (
 	"fmt"
 	"math"
+	"runtime"
 	"sort"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/beorn7/perks/quantile"
@@ -151,7 +153,7 @@ type SummaryOpts struct {
 	BufCap uint32
 }
 
-// Great fuck-up with the sliding-window decay algorithm... The Merge method of
+// 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
 // summaries in the first place. To avoid using Merge, we are currently adding
@@ -214,6 +216,17 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 		opts.BufCap = DefBufCap
 	}
 
+	if len(opts.Objectives) == 0 {
+		// Use the lock-free implementation of a Summary without objectives.
+		s := &noObjectivesSummary{
+			desc:       desc,
+			labelPairs: makeLabelPairs(desc, labelValues),
+			counts:     [2]*summaryCounts{&summaryCounts{}, &summaryCounts{}},
+		}
+		s.init(s) // Init self-collection.
+		return s
+	}
+
 	s := &summary{
 		desc: desc,
 
@@ -382,6 +395,142 @@ func (s *summary) swapBufs(now time.Time) {
 	}
 }
 
+type summaryCounts struct {
+	// sumBits contains the bits of the float64 representing the sum of all
+	// observations. sumBits and count have to go first in the struct to
+	// guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	sumBits uint64
+	count   uint64
+}
+
+type noObjectivesSummary struct {
+	// countAndHotIdx is a complicated one. For lock-free yet atomic
+	// observations, we need to save the total count of observations again,
+	// combined with the index of the currently-hot counts struct, so that
+	// we can perform the operation on both values atomically. The least
+	// significant bit defines the hot counts struct. The remaining 63 bits
+	// represent the total count of observations. This happens under the
+	// assumption that the 63bit count will never overflow. Rationale: An
+	// observations takes about 30ns. Let's assume it could happen in
+	// 10ns. Overflowing the counter will then take at least (2^63)*10ns,
+	// which is about 3000 years.
+	//
+	// This has to be first in the struct for 64bit alignment. See
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	countAndHotIdx uint64
+
+	selfCollector
+	desc     *Desc
+	writeMtx sync.Mutex // Only used in the Write method.
+
+	// Two counts, one is "hot" for lock-free observations, the other is
+	// "cold" for writing out a dto.Metric. It has to be an array of
+	// pointers to guarantee 64bit alignment of the histogramCounts, see
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG.
+	counts [2]*summaryCounts
+	hotIdx int // Index of currently-hot counts. Only used within Write.
+
+	labelPairs []*dto.LabelPair
+}
+
+func (s *noObjectivesSummary) Desc() *Desc {
+	return s.desc
+}
+
+func (s *noObjectivesSummary) Observe(v float64) {
+	// We increment s.countAndHotIdx by 2 so that the counter in the upper
+	// 63 bits gets incremented by 1. At the same time, we get the new value
+	// back, which we can use to find the currently-hot counts.
+	n := atomic.AddUint64(&s.countAndHotIdx, 2)
+	hotCounts := s.counts[n%2]
+
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			break
+		}
+	}
+	// Increment count last as we take it as a signal that the observation
+	// is complete.
+	atomic.AddUint64(&hotCounts.count, 1)
+}
+
+func (s *noObjectivesSummary) Write(out *dto.Metric) error {
+	var (
+		sum                   = &dto.Summary{}
+		hotCounts, coldCounts *summaryCounts
+		count                 uint64
+	)
+
+	// For simplicity, we mutex the rest of this method. It is not in the
+	// hot path, i.e.  Observe is called much more often than Write. The
+	// complication of making Write lock-free isn't worth it.
+	s.writeMtx.Lock()
+	defer s.writeMtx.Unlock()
+
+	// This is a bit arcane, which is why the following spells out this if
+	// clause in English:
+	//
+	// If the currently-hot counts struct is #0, we atomically increment
+	// s.countAndHotIdx by 1 so that from now on Observe will use the counts
+	// struct #1. Furthermore, the atomic increment gives us the new value,
+	// which, in its most significant 63 bits, tells us the count of
+	// observations done so far up to and including currently ongoing
+	// observations still using the counts struct just changed from hot to
+	// cold. To have a normal uint64 for the count, we bitshift by 1 and
+	// save the result in count. We also set s.hotIdx to 1 for the next
+	// Write call, and we will refer to counts #1 as hotCounts and to counts
+	// #0 as coldCounts.
+	//
+	// If the currently-hot counts struct is #1, we do the corresponding
+	// things the other way round. We have to _decrement_ s.countAndHotIdx
+	// (which is a bit arcane in itself, as we have to express -1 with an
+	// unsigned int...).
+	if s.hotIdx == 0 {
+		count = atomic.AddUint64(&s.countAndHotIdx, 1) >> 1
+		s.hotIdx = 1
+		hotCounts = s.counts[1]
+		coldCounts = s.counts[0]
+	} else {
+		count = atomic.AddUint64(&s.countAndHotIdx, ^uint64(0)) >> 1 // Decrement.
+		s.hotIdx = 0
+		hotCounts = s.counts[0]
+		coldCounts = s.counts[1]
+	}
+
+	// Now we have to wait for the now-declared-cold counts to actually cool
+	// down, i.e. wait for all observations still using it to finish. That's
+	// the case once the count in the cold counts struct is the same as the
+	// one atomically retrieved from the upper 63bits of s.countAndHotIdx.
+	for {
+		if count == atomic.LoadUint64(&coldCounts.count) {
+			break
+		}
+		runtime.Gosched() // Let observations get work done.
+	}
+
+	sum.SampleCount = proto.Uint64(count)
+	sum.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&coldCounts.sumBits)))
+
+	out.Summary = sum
+	out.Label = s.labelPairs
+
+	// Finally add all the cold counts to the new hot counts and reset the cold counts.
+	atomic.AddUint64(&hotCounts.count, count)
+	atomic.StoreUint64(&coldCounts.count, 0)
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + sum.GetSampleSum())
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			atomic.StoreUint64(&coldCounts.sumBits, 0)
+			break
+		}
+	}
+	return nil
+}
+
 type quantSort []*dto.Quantile
 
 func (s quantSort) Len() int {