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 {

vendor/github.com/prometheus/common/log/eventlog_formatter.go

@@ -0,0 +1,89 @@
+// Copyright 2015 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.
+
+// +build windows
+
+package log
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/sys/windows/svc/eventlog"
+
+	"github.com/sirupsen/logrus"
+)
+
+func init() {
+	setEventlogFormatter = func(l logger, name string, debugAsInfo bool) error {
+		if name == "" {
+			return fmt.Errorf("missing name parameter")
+		}
+
+		fmter, err := newEventlogger(name, debugAsInfo, l.entry.Logger.Formatter)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error creating eventlog formatter: %v\n", err)
+			l.Errorf("can't connect logger to eventlog: %v", err)
+			return err
+		}
+		l.entry.Logger.Formatter = fmter
+		return nil
+	}
+}
+
+type eventlogger struct {
+	log         *eventlog.Log
+	debugAsInfo bool
+	wrap        logrus.Formatter
+}
+
+func newEventlogger(name string, debugAsInfo bool, fmter logrus.Formatter) (*eventlogger, error) {
+	logHandle, err := eventlog.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return &eventlogger{log: logHandle, debugAsInfo: debugAsInfo, wrap: fmter}, nil
+}
+
+func (s *eventlogger) Format(e *logrus.Entry) ([]byte, error) {
+	data, err := s.wrap.Format(e)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "eventlogger: can't format entry: %v\n", err)
+		return data, err
+	}
+
+	switch e.Level {
+	case logrus.PanicLevel:
+		fallthrough
+	case logrus.FatalLevel:
+		fallthrough
+	case logrus.ErrorLevel:
+		err = s.log.Error(102, e.Message)
+	case logrus.WarnLevel:
+		err = s.log.Warning(101, e.Message)
+	case logrus.InfoLevel:
+		err = s.log.Info(100, e.Message)
+	case logrus.DebugLevel:
+		if s.debugAsInfo {
+			err = s.log.Info(100, e.Message)
+		}
+	default:
+		err = s.log.Info(100, e.Message)
+	}
+
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "eventlogger: can't send log to eventlog: %v\n", err)
+	}
+
+	return data, err
+}

vendor/github.com/prometheus/common/log/log.go

@@ -0,0 +1,364 @@
+// Copyright 2015 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 log
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/url"
+	"os"
+	"runtime"
+	"strconv"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+	"gopkg.in/alecthomas/kingpin.v2"
+)
+
+// setSyslogFormatter is nil if the target architecture does not support syslog.
+var setSyslogFormatter func(logger, string, string) error
+
+// setEventlogFormatter is nil if the target OS does not support Eventlog (i.e., is not Windows).
+var setEventlogFormatter func(logger, string, bool) error
+
+func setJSONFormatter() {
+	origLogger.Formatter = &logrus.JSONFormatter{}
+}
+
+type loggerSettings struct {
+	level  string
+	format string
+}
+
+func (s *loggerSettings) apply(ctx *kingpin.ParseContext) error {
+	err := baseLogger.SetLevel(s.level)
+	if err != nil {
+		return err
+	}
+	err = baseLogger.SetFormat(s.format)
+	return err
+}
+
+// AddFlags adds the flags used by this package to the Kingpin application.
+// To use the default Kingpin application, call AddFlags(kingpin.CommandLine)
+func AddFlags(a *kingpin.Application) {
+	s := loggerSettings{}
+	a.Flag("log.level", "Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]").
+		Default(origLogger.Level.String()).
+		StringVar(&s.level)
+	defaultFormat := url.URL{Scheme: "logger", Opaque: "stderr"}
+	a.Flag("log.format", `Set the log target and format. Example: "logger:syslog?appname=bob&local=7" or "logger:stdout?json=true"`).
+		Default(defaultFormat.String()).
+		StringVar(&s.format)
+	a.Action(s.apply)
+}
+
+// Logger is the interface for loggers used in the Prometheus components.
+type Logger interface {
+	Debug(...interface{})
+	Debugln(...interface{})
+	Debugf(string, ...interface{})
+
+	Info(...interface{})
+	Infoln(...interface{})
+	Infof(string, ...interface{})
+
+	Warn(...interface{})
+	Warnln(...interface{})
+	Warnf(string, ...interface{})
+
+	Error(...interface{})
+	Errorln(...interface{})
+	Errorf(string, ...interface{})
+
+	Fatal(...interface{})
+	Fatalln(...interface{})
+	Fatalf(string, ...interface{})
+
+	With(key string, value interface{}) Logger
+
+	SetFormat(string) error
+	SetLevel(string) error
+}
+
+type logger struct {
+	entry *logrus.Entry
+}
+
+func (l logger) With(key string, value interface{}) Logger {
+	return logger{l.entry.WithField(key, value)}
+}
+
+// Debug logs a message at level Debug on the standard logger.
+func (l logger) Debug(args ...interface{}) {
+	l.sourced().Debug(args...)
+}
+
+// Debug logs a message at level Debug on the standard logger.
+func (l logger) Debugln(args ...interface{}) {
+	l.sourced().Debugln(args...)
+}
+
+// Debugf logs a message at level Debug on the standard logger.
+func (l logger) Debugf(format string, args ...interface{}) {
+	l.sourced().Debugf(format, args...)
+}
+
+// Info logs a message at level Info on the standard logger.
+func (l logger) Info(args ...interface{}) {
+	l.sourced().Info(args...)
+}
+
+// Info logs a message at level Info on the standard logger.
+func (l logger) Infoln(args ...interface{}) {
+	l.sourced().Infoln(args...)
+}
+
+// Infof logs a message at level Info on the standard logger.
+func (l logger) Infof(format string, args ...interface{}) {
+	l.sourced().Infof(format, args...)
+}
+
+// Warn logs a message at level Warn on the standard logger.
+func (l logger) Warn(args ...interface{}) {
+	l.sourced().Warn(args...)
+}
+
+// Warn logs a message at level Warn on the standard logger.
+func (l logger) Warnln(args ...interface{}) {
+	l.sourced().Warnln(args...)
+}
+
+// Warnf logs a message at level Warn on the standard logger.
+func (l logger) Warnf(format string, args ...interface{}) {
+	l.sourced().Warnf(format, args...)
+}
+
+// Error logs a message at level Error on the standard logger.
+func (l logger) Error(args ...interface{}) {
+	l.sourced().Error(args...)
+}
+
+// Error logs a message at level Error on the standard logger.
+func (l logger) Errorln(args ...interface{}) {
+	l.sourced().Errorln(args...)
+}
+
+// Errorf logs a message at level Error on the standard logger.
+func (l logger) Errorf(format string, args ...interface{}) {
+	l.sourced().Errorf(format, args...)
+}
+
+// Fatal logs a message at level Fatal on the standard logger.
+func (l logger) Fatal(args ...interface{}) {
+	l.sourced().Fatal(args...)
+}
+
+// Fatal logs a message at level Fatal on the standard logger.
+func (l logger) Fatalln(args ...interface{}) {
+	l.sourced().Fatalln(args...)
+}
+
+// Fatalf logs a message at level Fatal on the standard logger.
+func (l logger) Fatalf(format string, args ...interface{}) {
+	l.sourced().Fatalf(format, args...)
+}
+
+func (l logger) SetLevel(level string) error {
+	lvl, err := logrus.ParseLevel(level)
+	if err != nil {
+		return err
+	}
+
+	l.entry.Logger.Level = lvl
+	return nil
+}
+
+func (l logger) SetFormat(format string) error {
+	u, err := url.Parse(format)
+	if err != nil {
+		return err
+	}
+	if u.Scheme != "logger" {
+		return fmt.Errorf("invalid scheme %s", u.Scheme)
+	}
+	jsonq := u.Query().Get("json")
+	if jsonq == "true" {
+		setJSONFormatter()
+	}
+
+	switch u.Opaque {
+	case "syslog":
+		if setSyslogFormatter == nil {
+			return fmt.Errorf("system does not support syslog")
+		}
+		appname := u.Query().Get("appname")
+		facility := u.Query().Get("local")
+		return setSyslogFormatter(l, appname, facility)
+	case "eventlog":
+		if setEventlogFormatter == nil {
+			return fmt.Errorf("system does not support eventlog")
+		}
+		name := u.Query().Get("name")
+		debugAsInfo := false
+		debugAsInfoRaw := u.Query().Get("debugAsInfo")
+		if parsedDebugAsInfo, err := strconv.ParseBool(debugAsInfoRaw); err == nil {
+			debugAsInfo = parsedDebugAsInfo
+		}
+		return setEventlogFormatter(l, name, debugAsInfo)
+	case "stdout":
+		l.entry.Logger.Out = os.Stdout
+	case "stderr":
+		l.entry.Logger.Out = os.Stderr
+	default:
+		return fmt.Errorf("unsupported logger %q", u.Opaque)
+	}
+	return nil
+}
+
+// sourced adds a source field to the logger that contains
+// the file name and line where the logging happened.
+func (l logger) sourced() *logrus.Entry {
+	_, file, line, ok := runtime.Caller(2)
+	if !ok {
+		file = "<???>"
+		line = 1
+	} else {
+		slash := strings.LastIndex(file, "/")
+		file = file[slash+1:]
+	}
+	return l.entry.WithField("source", fmt.Sprintf("%s:%d", file, line))
+}
+
+var origLogger = logrus.New()
+var baseLogger = logger{entry: logrus.NewEntry(origLogger)}
+
+// Base returns the default Logger logging to
+func Base() Logger {
+	return baseLogger
+}
+
+// NewLogger returns a new Logger logging to out.
+func NewLogger(w io.Writer) Logger {
+	l := logrus.New()
+	l.Out = w
+	return logger{entry: logrus.NewEntry(l)}
+}
+
+// NewNopLogger returns a logger that discards all log messages.
+func NewNopLogger() Logger {
+	l := logrus.New()
+	l.Out = ioutil.Discard
+	return logger{entry: logrus.NewEntry(l)}
+}
+
+// With adds a field to the logger.
+func With(key string, value interface{}) Logger {
+	return baseLogger.With(key, value)
+}
+
+// Debug logs a message at level Debug on the standard logger.
+func Debug(args ...interface{}) {
+	baseLogger.sourced().Debug(args...)
+}
+
+// Debugln logs a message at level Debug on the standard logger.
+func Debugln(args ...interface{}) {
+	baseLogger.sourced().Debugln(args...)
+}
+
+// Debugf logs a message at level Debug on the standard logger.
+func Debugf(format string, args ...interface{}) {
+	baseLogger.sourced().Debugf(format, args...)
+}
+
+// Info logs a message at level Info on the standard logger.
+func Info(args ...interface{}) {
+	baseLogger.sourced().Info(args...)
+}
+
+// Infoln logs a message at level Info on the standard logger.
+func Infoln(args ...interface{}) {
+	baseLogger.sourced().Infoln(args...)
+}
+
+// Infof logs a message at level Info on the standard logger.
+func Infof(format string, args ...interface{}) {
+	baseLogger.sourced().Infof(format, args...)
+}
+
+// Warn logs a message at level Warn on the standard logger.
+func Warn(args ...interface{}) {
+	baseLogger.sourced().Warn(args...)
+}
+
+// Warnln logs a message at level Warn on the standard logger.
+func Warnln(args ...interface{}) {
+	baseLogger.sourced().Warnln(args...)
+}
+
+// Warnf logs a message at level Warn on the standard logger.
+func Warnf(format string, args ...interface{}) {
+	baseLogger.sourced().Warnf(format, args...)
+}
+
+// Error logs a message at level Error on the standard logger.
+func Error(args ...interface{}) {
+	baseLogger.sourced().Error(args...)
+}
+
+// Errorln logs a message at level Error on the standard logger.
+func Errorln(args ...interface{}) {
+	baseLogger.sourced().Errorln(args...)
+}
+
+// Errorf logs a message at level Error on the standard logger.
+func Errorf(format string, args ...interface{}) {
+	baseLogger.sourced().Errorf(format, args...)
+}
+
+// Fatal logs a message at level Fatal on the standard logger.
+func Fatal(args ...interface{}) {
+	baseLogger.sourced().Fatal(args...)
+}
+
+// Fatalln logs a message at level Fatal on the standard logger.
+func Fatalln(args ...interface{}) {
+	baseLogger.sourced().Fatalln(args...)
+}
+
+// Fatalf logs a message at level Fatal on the standard logger.
+func Fatalf(format string, args ...interface{}) {
+	baseLogger.sourced().Fatalf(format, args...)
+}
+
+// AddHook adds hook to Prometheus' original logger.
+func AddHook(hook logrus.Hook) {
+	origLogger.Hooks.Add(hook)
+}
+
+type errorLogWriter struct{}
+
+func (errorLogWriter) Write(b []byte) (int, error) {
+	baseLogger.sourced().Error(string(b))
+	return len(b), nil
+}
+
+// NewErrorLogger returns a log.Logger that is meant to be used
+// in the ErrorLog field of an http.Server to log HTTP server errors.
+func NewErrorLogger() *log.Logger {
+	return log.New(&errorLogWriter{}, "", 0)
+}

vendor/github.com/prometheus/common/log/syslog_formatter.go

@@ -0,0 +1,126 @@
+// Copyright 2015 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.
+
+// +build !windows,!nacl,!plan9
+
+package log
+
+import (
+	"fmt"
+	"log/syslog"
+	"os"
+
+	"github.com/sirupsen/logrus"
+)
+
+var _ logrus.Formatter = (*syslogger)(nil)
+
+func init() {
+	setSyslogFormatter = func(l logger, appname, local string) error {
+		if appname == "" {
+			return fmt.Errorf("missing appname parameter")
+		}
+		if local == "" {
+			return fmt.Errorf("missing local parameter")
+		}
+
+		fmter, err := newSyslogger(appname, local, l.entry.Logger.Formatter)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error creating syslog formatter: %v\n", err)
+			l.entry.Errorf("can't connect logger to syslog: %v", err)
+			return err
+		}
+		l.entry.Logger.Formatter = fmter
+		return nil
+	}
+}
+
+var prefixTag []byte
+
+type syslogger struct {
+	wrap logrus.Formatter
+	out  *syslog.Writer
+}
+
+func newSyslogger(appname string, facility string, fmter logrus.Formatter) (*syslogger, error) {
+	priority, err := getFacility(facility)
+	if err != nil {
+		return nil, err
+	}
+	out, err := syslog.New(priority, appname)
+	_, isJSON := fmter.(*logrus.JSONFormatter)
+	if isJSON {
+		// add cee tag to json formatted syslogs
+		prefixTag = []byte("@cee:")
+	}
+	return &syslogger{
+		out:  out,
+		wrap: fmter,
+	}, err
+}
+
+func getFacility(facility string) (syslog.Priority, error) {
+	switch facility {
+	case "0":
+		return syslog.LOG_LOCAL0, nil
+	case "1":
+		return syslog.LOG_LOCAL1, nil
+	case "2":
+		return syslog.LOG_LOCAL2, nil
+	case "3":
+		return syslog.LOG_LOCAL3, nil
+	case "4":
+		return syslog.LOG_LOCAL4, nil
+	case "5":
+		return syslog.LOG_LOCAL5, nil
+	case "6":
+		return syslog.LOG_LOCAL6, nil
+	case "7":
+		return syslog.LOG_LOCAL7, nil
+	}
+	return syslog.LOG_LOCAL0, fmt.Errorf("invalid local(%s) for syslog", facility)
+}
+
+func (s *syslogger) Format(e *logrus.Entry) ([]byte, error) {
+	data, err := s.wrap.Format(e)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "syslogger: can't format entry: %v\n", err)
+		return data, err
+	}
+	// only append tag to data sent to syslog (line), not to what
+	// is returned
+	line := string(append(prefixTag, data...))
+
+	switch e.Level {
+	case logrus.PanicLevel:
+		err = s.out.Crit(line)
+	case logrus.FatalLevel:
+		err = s.out.Crit(line)
+	case logrus.ErrorLevel:
+		err = s.out.Err(line)
+	case logrus.WarnLevel:
+		err = s.out.Warning(line)
+	case logrus.InfoLevel:
+		err = s.out.Info(line)
+	case logrus.DebugLevel:
+		err = s.out.Debug(line)
+	default:
+		err = s.out.Notice(line)
+	}
+
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "syslogger: can't send log to syslog: %v\n", err)
+	}
+
+	return data, err
+}