diff options
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/registry.go')
| -rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/registry.go | 1076 |
1 files changed, 0 insertions, 1076 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/registry.go b/vendor/github.com/prometheus/client_golang/prometheus/registry.go deleted file mode 100644 index c6fd2f58b..000000000 --- a/vendor/github.com/prometheus/client_golang/prometheus/registry.go +++ /dev/null @@ -1,1076 +0,0 @@ -// Copyright 2014 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 - -import ( - "bytes" - "errors" - "fmt" - "os" - "path/filepath" - "runtime" - "sort" - "strconv" - "strings" - "sync" - "unicode/utf8" - - "github.com/prometheus/client_golang/prometheus/internal" - - "github.com/cespare/xxhash/v2" - dto "github.com/prometheus/client_model/go" - "github.com/prometheus/common/expfmt" - "google.golang.org/protobuf/proto" -) - -const ( - // Capacity for the channel to collect metrics and descriptors. - capMetricChan = 1000 - capDescChan = 10 -) - -// DefaultRegisterer and DefaultGatherer are the implementations of the -// Registerer and Gatherer interface a number of convenience functions in this -// package act on. Initially, both variables point to the same Registry, which -// has a process collector (currently on Linux only, see NewProcessCollector) -// and a Go collector (see NewGoCollector, in particular the note about -// stop-the-world implication with Go versions older than 1.9) already -// registered. This approach to keep default instances as global state mirrors -// the approach of other packages in the Go standard library. Note that there -// are caveats. Change the variables with caution and only if you understand the -// consequences. Users who want to avoid global state altogether should not use -// the convenience functions and act on custom instances instead. -var ( - defaultRegistry = NewRegistry() - DefaultRegisterer Registerer = defaultRegistry - DefaultGatherer Gatherer = defaultRegistry -) - -func init() { - MustRegister(NewProcessCollector(ProcessCollectorOpts{})) - MustRegister(NewGoCollector()) -} - -// NewRegistry creates a new vanilla Registry without any Collectors -// pre-registered. -func NewRegistry() *Registry { - return &Registry{ - collectorsByID: map[uint64]Collector{}, - descIDs: map[uint64]struct{}{}, - dimHashesByName: map[string]uint64{}, - } -} - -// NewPedanticRegistry returns a registry that checks during collection if each -// collected Metric is consistent with its reported Desc, and if the Desc has -// actually been registered with the registry. Unchecked Collectors (those whose -// Describe method does not yield any descriptors) are excluded from the check. -// -// Usually, a Registry will be happy as long as the union of all collected -// Metrics is consistent and valid even if some metrics are not consistent with -// their own Desc or a Desc provided by their registered Collector. Well-behaved -// Collectors and Metrics will only provide consistent Descs. This Registry is -// useful to test the implementation of Collectors and Metrics. -func NewPedanticRegistry() *Registry { - r := NewRegistry() - r.pedanticChecksEnabled = true - return r -} - -// Registerer is the interface for the part of a registry in charge of -// registering and unregistering. Users of custom registries should use -// Registerer as type for registration purposes (rather than the Registry type -// directly). In that way, they are free to use custom Registerer implementation -// (e.g. for testing purposes). -type Registerer interface { - // Register registers a new Collector to be included in metrics - // collection. It returns an error if the descriptors provided by the - // Collector are invalid or if they — in combination with descriptors of - // already registered Collectors — do not fulfill the consistency and - // uniqueness criteria described in the documentation of metric.Desc. - // - // If the provided Collector is equal to a Collector already registered - // (which includes the case of re-registering the same Collector), the - // returned error is an instance of AlreadyRegisteredError, which - // contains the previously registered Collector. - // - // A Collector whose Describe method does not yield any Desc is treated - // as unchecked. Registration will always succeed. No check for - // re-registering (see previous paragraph) is performed. Thus, the - // caller is responsible for not double-registering the same unchecked - // Collector, and for providing a Collector that will not cause - // inconsistent metrics on collection. (This would lead to scrape - // errors.) - Register(Collector) error - // MustRegister works like Register but registers any number of - // Collectors and panics upon the first registration that causes an - // error. - MustRegister(...Collector) - // Unregister unregisters the Collector that equals the Collector passed - // in as an argument. (Two Collectors are considered equal if their - // Describe method yields the same set of descriptors.) The function - // returns whether a Collector was unregistered. Note that an unchecked - // Collector cannot be unregistered (as its Describe method does not - // yield any descriptor). - // - // Note that even after unregistering, it will not be possible to - // register a new Collector that is inconsistent with the unregistered - // Collector, e.g. a Collector collecting metrics with the same name but - // a different help string. The rationale here is that the same registry - // instance must only collect consistent metrics throughout its - // lifetime. - Unregister(Collector) bool -} - -// Gatherer is the interface for the part of a registry in charge of gathering -// the collected metrics into a number of MetricFamilies. The Gatherer interface -// comes with the same general implication as described for the Registerer -// interface. -type Gatherer interface { - // Gather calls the Collect method of the registered Collectors and then - // gathers the collected metrics into a lexicographically sorted slice - // of uniquely named MetricFamily protobufs. Gather ensures that the - // returned slice is valid and self-consistent so that it can be used - // for valid exposition. As an exception to the strict consistency - // requirements described for metric.Desc, Gather will tolerate - // different sets of label names for metrics of the same metric family. - // - // Even if an error occurs, Gather attempts to gather as many metrics as - // possible. Hence, if a non-nil error is returned, the returned - // MetricFamily slice could be nil (in case of a fatal error that - // prevented any meaningful metric collection) or contain a number of - // MetricFamily protobufs, some of which might be incomplete, and some - // might be missing altogether. The returned error (which might be a - // MultiError) explains the details. Note that this is mostly useful for - // debugging purposes. If the gathered protobufs are to be used for - // exposition in actual monitoring, it is almost always better to not - // expose an incomplete result and instead disregard the returned - // MetricFamily protobufs in case the returned error is non-nil. - Gather() ([]*dto.MetricFamily, error) -} - -// Register registers the provided Collector with the DefaultRegisterer. -// -// Register is a shortcut for DefaultRegisterer.Register(c). See there for more -// details. -func Register(c Collector) error { - return DefaultRegisterer.Register(c) -} - -// MustRegister registers the provided Collectors with the DefaultRegisterer and -// panics if any error occurs. -// -// MustRegister is a shortcut for DefaultRegisterer.MustRegister(cs...). See -// there for more details. -func MustRegister(cs ...Collector) { - DefaultRegisterer.MustRegister(cs...) -} - -// Unregister removes the registration of the provided Collector from the -// DefaultRegisterer. -// -// Unregister is a shortcut for DefaultRegisterer.Unregister(c). See there for -// more details. -func Unregister(c Collector) bool { - return DefaultRegisterer.Unregister(c) -} - -// GathererFunc turns a function into a Gatherer. -type GathererFunc func() ([]*dto.MetricFamily, error) - -// Gather implements Gatherer. -func (gf GathererFunc) Gather() ([]*dto.MetricFamily, error) { - return gf() -} - -// AlreadyRegisteredError is returned by the Register method if the Collector to -// be registered has already been registered before, or a different Collector -// that collects the same metrics has been registered before. Registration fails -// in that case, but you can detect from the kind of error what has -// happened. The error contains fields for the existing Collector and the -// (rejected) new Collector that equals the existing one. This can be used to -// find out if an equal Collector has been registered before and switch over to -// using the old one, as demonstrated in the example. -type AlreadyRegisteredError struct { - ExistingCollector, NewCollector Collector -} - -func (err AlreadyRegisteredError) Error() string { - return "duplicate metrics collector registration attempted" -} - -// MultiError is a slice of errors implementing the error interface. It is used -// by a Gatherer to report multiple errors during MetricFamily gathering. -type MultiError []error - -// Error formats the contained errors as a bullet point list, preceded by the -// total number of errors. Note that this results in a multi-line string. -func (errs MultiError) Error() string { - if len(errs) == 0 { - return "" - } - buf := &bytes.Buffer{} - fmt.Fprintf(buf, "%d error(s) occurred:", len(errs)) - for _, err := range errs { - fmt.Fprintf(buf, "\n* %s", err) - } - return buf.String() -} - -// Append appends the provided error if it is not nil. -func (errs *MultiError) Append(err error) { - if err != nil { - *errs = append(*errs, err) - } -} - -// MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only -// contained error as error if len(errs is 1). In all other cases, it returns -// the MultiError directly. This is helpful for returning a MultiError in a way -// that only uses the MultiError if needed. -func (errs MultiError) MaybeUnwrap() error { - switch len(errs) { - case 0: - return nil - case 1: - return errs[0] - default: - return errs - } -} - -// Registry registers Prometheus collectors, collects their metrics, and gathers -// them into MetricFamilies for exposition. It implements Registerer, Gatherer, -// and Collector. The zero value is not usable. Create instances with -// NewRegistry or NewPedanticRegistry. -// -// Registry implements Collector to allow it to be used for creating groups of -// metrics. See the Grouping example for how this can be done. -type Registry struct { - mtx sync.RWMutex - collectorsByID map[uint64]Collector // ID is a hash of the descIDs. - descIDs map[uint64]struct{} - dimHashesByName map[string]uint64 - uncheckedCollectors []Collector - pedanticChecksEnabled bool -} - -// Register implements Registerer. -func (r *Registry) Register(c Collector) error { - var ( - descChan = make(chan *Desc, capDescChan) - newDescIDs = map[uint64]struct{}{} - newDimHashesByName = map[string]uint64{} - collectorID uint64 // All desc IDs XOR'd together. - duplicateDescErr error - ) - go func() { - c.Describe(descChan) - close(descChan) - }() - r.mtx.Lock() - defer func() { - // Drain channel in case of premature return to not leak a goroutine. - for range descChan { - } - r.mtx.Unlock() - }() - // Conduct various tests... - for desc := range descChan { - - // Is the descriptor valid at all? - if desc.err != nil { - return fmt.Errorf("descriptor %s is invalid: %w", desc, desc.err) - } - - // Is the descID unique? - // (In other words: Is the fqName + constLabel combination unique?) - if _, exists := r.descIDs[desc.id]; exists { - duplicateDescErr = fmt.Errorf("descriptor %s already exists with the same fully-qualified name and const label values", desc) - } - // If it is not a duplicate desc in this collector, XOR it to - // the collectorID. (We allow duplicate descs within the same - // collector, but their existence must be a no-op.) - if _, exists := newDescIDs[desc.id]; !exists { - newDescIDs[desc.id] = struct{}{} - collectorID ^= desc.id - } - - // Are all the label names and the help string consistent with - // previous descriptors of the same name? - // First check existing descriptors... - if dimHash, exists := r.dimHashesByName[desc.fqName]; exists { - if dimHash != desc.dimHash { - return fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc) - } - continue - } - - // ...then check the new descriptors already seen. - if dimHash, exists := newDimHashesByName[desc.fqName]; exists { - if dimHash != desc.dimHash { - return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc) - } - continue - } - newDimHashesByName[desc.fqName] = desc.dimHash - } - // A Collector yielding no Desc at all is considered unchecked. - if len(newDescIDs) == 0 { - r.uncheckedCollectors = append(r.uncheckedCollectors, c) - return nil - } - if existing, exists := r.collectorsByID[collectorID]; exists { - switch e := existing.(type) { - case *wrappingCollector: - return AlreadyRegisteredError{ - ExistingCollector: e.unwrapRecursively(), - NewCollector: c, - } - default: - return AlreadyRegisteredError{ - ExistingCollector: e, - NewCollector: c, - } - } - } - // If the collectorID is new, but at least one of the descs existed - // before, we are in trouble. - if duplicateDescErr != nil { - return duplicateDescErr - } - - // Only after all tests have passed, actually register. - r.collectorsByID[collectorID] = c - for hash := range newDescIDs { - r.descIDs[hash] = struct{}{} - } - for name, dimHash := range newDimHashesByName { - r.dimHashesByName[name] = dimHash - } - return nil -} - -// Unregister implements Registerer. -func (r *Registry) Unregister(c Collector) bool { - var ( - descChan = make(chan *Desc, capDescChan) - descIDs = map[uint64]struct{}{} - collectorID uint64 // All desc IDs XOR'd together. - ) - go func() { - c.Describe(descChan) - close(descChan) - }() - for desc := range descChan { - if _, exists := descIDs[desc.id]; !exists { - collectorID ^= desc.id - descIDs[desc.id] = struct{}{} - } - } - - r.mtx.RLock() - if _, exists := r.collectorsByID[collectorID]; !exists { - r.mtx.RUnlock() - return false - } - r.mtx.RUnlock() - - r.mtx.Lock() - defer r.mtx.Unlock() - - delete(r.collectorsByID, collectorID) - for id := range descIDs { - delete(r.descIDs, id) - } - // dimHashesByName is left untouched as those must be consistent - // throughout the lifetime of a program. - return true -} - -// MustRegister implements Registerer. -func (r *Registry) MustRegister(cs ...Collector) { - for _, c := range cs { - if err := r.Register(c); err != nil { - panic(err) - } - } -} - -// Gather implements Gatherer. -func (r *Registry) Gather() ([]*dto.MetricFamily, error) { - r.mtx.RLock() - - if len(r.collectorsByID) == 0 && len(r.uncheckedCollectors) == 0 { - // Fast path. - r.mtx.RUnlock() - return nil, nil - } - - var ( - checkedMetricChan = make(chan Metric, capMetricChan) - uncheckedMetricChan = make(chan Metric, capMetricChan) - metricHashes = map[uint64]struct{}{} - wg sync.WaitGroup - errs MultiError // The collected errors to return in the end. - registeredDescIDs map[uint64]struct{} // Only used for pedantic checks - ) - - goroutineBudget := len(r.collectorsByID) + len(r.uncheckedCollectors) - metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName)) - checkedCollectors := make(chan Collector, len(r.collectorsByID)) - uncheckedCollectors := make(chan Collector, len(r.uncheckedCollectors)) - for _, collector := range r.collectorsByID { - checkedCollectors <- collector - } - for _, collector := range r.uncheckedCollectors { - uncheckedCollectors <- collector - } - // In case pedantic checks are enabled, we have to copy the map before - // giving up the RLock. - if r.pedanticChecksEnabled { - registeredDescIDs = make(map[uint64]struct{}, len(r.descIDs)) - for id := range r.descIDs { - registeredDescIDs[id] = struct{}{} - } - } - r.mtx.RUnlock() - - wg.Add(goroutineBudget) - - collectWorker := func() { - for { - select { - case collector := <-checkedCollectors: - collector.Collect(checkedMetricChan) - case collector := <-uncheckedCollectors: - collector.Collect(uncheckedMetricChan) - default: - return - } - wg.Done() - } - } - - // Start the first worker now to make sure at least one is running. - go collectWorker() - goroutineBudget-- - - // Close checkedMetricChan and uncheckedMetricChan once all collectors - // are collected. - go func() { - wg.Wait() - close(checkedMetricChan) - close(uncheckedMetricChan) - }() - - // Drain checkedMetricChan and uncheckedMetricChan in case of premature return. - defer func() { - if checkedMetricChan != nil { - for range checkedMetricChan { - } - } - if uncheckedMetricChan != nil { - for range uncheckedMetricChan { - } - } - }() - - // Copy the channel references so we can nil them out later to remove - // them from the select statements below. - cmc := checkedMetricChan - umc := uncheckedMetricChan - - for { - select { - case metric, ok := <-cmc: - if !ok { - cmc = nil - break - } - errs.Append(processMetric( - metric, metricFamiliesByName, - metricHashes, - registeredDescIDs, - )) - case metric, ok := <-umc: - if !ok { - umc = nil - break - } - errs.Append(processMetric( - metric, metricFamiliesByName, - metricHashes, - nil, - )) - default: - if goroutineBudget <= 0 || len(checkedCollectors)+len(uncheckedCollectors) == 0 { - // All collectors are already being worked on or - // we have already as many goroutines started as - // there are collectors. Do the same as above, - // just without the default. - select { - case metric, ok := <-cmc: - if !ok { - cmc = nil - break - } - errs.Append(processMetric( - metric, metricFamiliesByName, - metricHashes, - registeredDescIDs, - )) - case metric, ok := <-umc: - if !ok { - umc = nil - break - } - errs.Append(processMetric( - metric, metricFamiliesByName, - metricHashes, - nil, - )) - } - break - } - // Start more workers. - go collectWorker() - goroutineBudget-- - runtime.Gosched() - } - // Once both checkedMetricChan and uncheckedMetricChan are closed - // and drained, the contraption above will nil out cmc and umc, - // and then we can leave the collect loop here. - if cmc == nil && umc == nil { - break - } - } - return internal.NormalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap() -} - -// Describe implements Collector. -func (r *Registry) Describe(ch chan<- *Desc) { - r.mtx.RLock() - defer r.mtx.RUnlock() - - // Only report the checked Collectors; unchecked collectors don't report any - // Desc. - for _, c := range r.collectorsByID { - c.Describe(ch) - } -} - -// Collect implements Collector. -func (r *Registry) Collect(ch chan<- Metric) { - r.mtx.RLock() - defer r.mtx.RUnlock() - - for _, c := range r.collectorsByID { - c.Collect(ch) - } - for _, c := range r.uncheckedCollectors { - c.Collect(ch) - } -} - -// WriteToTextfile calls Gather on the provided Gatherer, encodes the result in the -// Prometheus text format, and writes it to a temporary file. Upon success, the -// temporary file is renamed to the provided filename. -// -// This is intended for use with the textfile collector of the node exporter. -// Note that the node exporter expects the filename to be suffixed with ".prom". -func WriteToTextfile(filename string, g Gatherer) error { - tmp, err := os.CreateTemp(filepath.Dir(filename), filepath.Base(filename)) - if err != nil { - return err - } - defer os.Remove(tmp.Name()) - - mfs, err := g.Gather() - if err != nil { - return err - } - for _, mf := range mfs { - if _, err := expfmt.MetricFamilyToText(tmp, mf); err != nil { - return err - } - } - if err := tmp.Close(); err != nil { - return err - } - - if err := os.Chmod(tmp.Name(), 0o644); err != nil { - return err - } - return os.Rename(tmp.Name(), filename) -} - -// processMetric is an internal helper method only used by the Gather method. -func processMetric( - metric Metric, - metricFamiliesByName map[string]*dto.MetricFamily, - metricHashes map[uint64]struct{}, - registeredDescIDs map[uint64]struct{}, -) error { - desc := metric.Desc() - // Wrapped metrics collected by an unchecked Collector can have an - // invalid Desc. - if desc.err != nil { - return desc.err - } - dtoMetric := &dto.Metric{} - if err := metric.Write(dtoMetric); err != nil { - return fmt.Errorf("error collecting metric %v: %w", desc, err) - } - metricFamily, ok := metricFamiliesByName[desc.fqName] - if ok { // Existing name. - if metricFamily.GetHelp() != desc.help { - return fmt.Errorf( - "collected metric %s %s has help %q but should have %q", - desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(), - ) - } - // TODO(beorn7): Simplify switch once Desc has type. - switch metricFamily.GetType() { - case dto.MetricType_COUNTER: - if dtoMetric.Counter == nil { - return fmt.Errorf( - "collected metric %s %s should be a Counter", - desc.fqName, dtoMetric, - ) - } - case dto.MetricType_GAUGE: - if dtoMetric.Gauge == nil { - return fmt.Errorf( - "collected metric %s %s should be a Gauge", - desc.fqName, dtoMetric, - ) - } - case dto.MetricType_SUMMARY: - if dtoMetric.Summary == nil { - return fmt.Errorf( - "collected metric %s %s should be a Summary", - desc.fqName, dtoMetric, - ) - } - case dto.MetricType_UNTYPED: - if dtoMetric.Untyped == nil { - return fmt.Errorf( - "collected metric %s %s should be Untyped", - desc.fqName, dtoMetric, - ) - } - case dto.MetricType_HISTOGRAM: - if dtoMetric.Histogram == nil { - return fmt.Errorf( - "collected metric %s %s should be a Histogram", - desc.fqName, dtoMetric, - ) - } - default: - panic("encountered MetricFamily with invalid type") - } - } else { // New name. - metricFamily = &dto.MetricFamily{} - metricFamily.Name = proto.String(desc.fqName) - metricFamily.Help = proto.String(desc.help) - // TODO(beorn7): Simplify switch once Desc has type. - switch { - case dtoMetric.Gauge != nil: - metricFamily.Type = dto.MetricType_GAUGE.Enum() - case dtoMetric.Counter != nil: - metricFamily.Type = dto.MetricType_COUNTER.Enum() - case dtoMetric.Summary != nil: - metricFamily.Type = dto.MetricType_SUMMARY.Enum() - case dtoMetric.Untyped != nil: - metricFamily.Type = dto.MetricType_UNTYPED.Enum() - case dtoMetric.Histogram != nil: - metricFamily.Type = dto.MetricType_HISTOGRAM.Enum() - default: - return fmt.Errorf("empty metric collected: %s", dtoMetric) - } - if err := checkSuffixCollisions(metricFamily, metricFamiliesByName); err != nil { - return err - } - metricFamiliesByName[desc.fqName] = metricFamily - } - if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes); err != nil { - return err - } - if registeredDescIDs != nil { - // Is the desc registered at all? - if _, exist := registeredDescIDs[desc.id]; !exist { - return fmt.Errorf( - "collected metric %s %s with unregistered descriptor %s", - metricFamily.GetName(), dtoMetric, desc, - ) - } - if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil { - return err - } - } - metricFamily.Metric = append(metricFamily.Metric, dtoMetric) - return nil -} - -// 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 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. -// -// Gatherers can be used to merge the Gather results from multiple -// Registries. It also provides a way to directly inject existing MetricFamily -// protobufs into the gathering by creating a custom Gatherer with a Gather -// method that simply returns the existing MetricFamily protobufs. Note that no -// registration is involved (in contrast to Collector registration), so -// obviously registration-time checks cannot happen. Any inconsistencies between -// the gathered MetricFamilies are reported as errors by the Gather method, and -// inconsistent Metrics are dropped. Invalid parts of the MetricFamilies -// (e.g. syntactically invalid metric or label names) will go undetected. -type Gatherers []Gatherer - -// Gather implements Gatherer. -func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) { - var ( - metricFamiliesByName = map[string]*dto.MetricFamily{} - metricHashes = map[uint64]struct{}{} - errs MultiError // The collected errors to return in the end. - ) - - for i, g := range gs { - mfs, err := g.Gather() - if err != nil { - multiErr := MultiError{} - if errors.As(err, &multiErr) { - for _, err := range multiErr { - errs = append(errs, fmt.Errorf("[from Gatherer #%d] %w", i+1, err)) - } - } else { - errs = append(errs, fmt.Errorf("[from Gatherer #%d] %w", i+1, err)) - } - } - for _, mf := range mfs { - existingMF, exists := metricFamiliesByName[mf.GetName()] - if exists { - if existingMF.GetHelp() != mf.GetHelp() { - errs = append(errs, fmt.Errorf( - "gathered metric family %s has help %q but should have %q", - mf.GetName(), mf.GetHelp(), existingMF.GetHelp(), - )) - continue - } - if existingMF.GetType() != mf.GetType() { - errs = append(errs, fmt.Errorf( - "gathered metric family %s has type %s but should have %s", - mf.GetName(), mf.GetType(), existingMF.GetType(), - )) - continue - } - } else { - existingMF = &dto.MetricFamily{} - existingMF.Name = mf.Name - existingMF.Help = mf.Help - existingMF.Type = mf.Type - if err := checkSuffixCollisions(existingMF, metricFamiliesByName); err != nil { - errs = append(errs, err) - continue - } - metricFamiliesByName[mf.GetName()] = existingMF - } - for _, m := range mf.Metric { - if err := checkMetricConsistency(existingMF, m, metricHashes); err != nil { - errs = append(errs, err) - continue - } - existingMF.Metric = append(existingMF.Metric, m) - } - } - } - return internal.NormalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap() -} - -// checkSuffixCollisions checks for collisions with the “magic” suffixes the -// Prometheus text format and the internal metric representation of the -// Prometheus server add while flattening Summaries and Histograms. -func checkSuffixCollisions(mf *dto.MetricFamily, mfs map[string]*dto.MetricFamily) error { - var ( - newName = mf.GetName() - newType = mf.GetType() - newNameWithoutSuffix = "" - ) - switch { - case strings.HasSuffix(newName, "_count"): - newNameWithoutSuffix = newName[:len(newName)-6] - case strings.HasSuffix(newName, "_sum"): - newNameWithoutSuffix = newName[:len(newName)-4] - case strings.HasSuffix(newName, "_bucket"): - newNameWithoutSuffix = newName[:len(newName)-7] - } - if newNameWithoutSuffix != "" { - if existingMF, ok := mfs[newNameWithoutSuffix]; ok { - switch existingMF.GetType() { - case dto.MetricType_SUMMARY: - if !strings.HasSuffix(newName, "_bucket") { - return fmt.Errorf( - "collected metric named %q collides with previously collected summary named %q", - newName, newNameWithoutSuffix, - ) - } - case dto.MetricType_HISTOGRAM: - return fmt.Errorf( - "collected metric named %q collides with previously collected histogram named %q", - newName, newNameWithoutSuffix, - ) - } - } - } - if newType == dto.MetricType_SUMMARY || newType == dto.MetricType_HISTOGRAM { - if _, ok := mfs[newName+"_count"]; ok { - return fmt.Errorf( - "collected histogram or summary named %q collides with previously collected metric named %q", - newName, newName+"_count", - ) - } - if _, ok := mfs[newName+"_sum"]; ok { - return fmt.Errorf( - "collected histogram or summary named %q collides with previously collected metric named %q", - newName, newName+"_sum", - ) - } - } - if newType == dto.MetricType_HISTOGRAM { - if _, ok := mfs[newName+"_bucket"]; ok { - return fmt.Errorf( - "collected histogram named %q collides with previously collected metric named %q", - newName, newName+"_bucket", - ) - } - } - return nil -} - -// checkMetricConsistency checks if the provided Metric is consistent with the -// provided MetricFamily. It also hashes the Metric labels and the MetricFamily -// name. If the resulting hash is already in the provided metricHashes, an error -// is returned. If not, it is added to metricHashes. -func checkMetricConsistency( - metricFamily *dto.MetricFamily, - dtoMetric *dto.Metric, - metricHashes map[uint64]struct{}, -) error { - name := metricFamily.GetName() - - // Type consistency with metric family. - if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil || - metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil || - metricFamily.GetType() == dto.MetricType_SUMMARY && dtoMetric.Summary == nil || - metricFamily.GetType() == dto.MetricType_HISTOGRAM && dtoMetric.Histogram == nil || - metricFamily.GetType() == dto.MetricType_UNTYPED && dtoMetric.Untyped == nil { - return fmt.Errorf( - "collected metric %q { %s} is not a %s", - name, dtoMetric, metricFamily.GetType(), - ) - } - - previousLabelName := "" - for _, labelPair := range dtoMetric.GetLabel() { - labelName := labelPair.GetName() - if labelName == previousLabelName { - return fmt.Errorf( - "collected metric %q { %s} has two or more labels with the same name: %s", - name, dtoMetric, labelName, - ) - } - if !checkLabelName(labelName) { - return fmt.Errorf( - "collected metric %q { %s} has a label with an invalid name: %s", - name, dtoMetric, labelName, - ) - } - if dtoMetric.Summary != nil && labelName == quantileLabel { - return fmt.Errorf( - "collected metric %q { %s} must not have an explicit %q label", - name, dtoMetric, quantileLabel, - ) - } - if !utf8.ValidString(labelPair.GetValue()) { - return fmt.Errorf( - "collected metric %q { %s} has a label named %q whose value is not utf8: %#v", - name, dtoMetric, labelName, labelPair.GetValue()) - } - previousLabelName = labelName - } - - // Is the metric unique (i.e. no other metric with the same name and the same labels)? - h := xxhash.New() - h.WriteString(name) - h.Write(separatorByteSlice) - // Make sure label pairs are sorted. We depend on it for the consistency - // check. - if !sort.IsSorted(internal.LabelPairSorter(dtoMetric.Label)) { - // We cannot sort dtoMetric.Label in place as it is immutable by contract. - copiedLabels := make([]*dto.LabelPair, len(dtoMetric.Label)) - copy(copiedLabels, dtoMetric.Label) - sort.Sort(internal.LabelPairSorter(copiedLabels)) - dtoMetric.Label = copiedLabels - } - for _, lp := range dtoMetric.Label { - h.WriteString(lp.GetName()) - h.Write(separatorByteSlice) - h.WriteString(lp.GetValue()) - h.Write(separatorByteSlice) - } - if dtoMetric.TimestampMs != nil { - h.WriteString(strconv.FormatInt(*(dtoMetric.TimestampMs), 10)) - h.Write(separatorByteSlice) - } - hSum := h.Sum64() - if _, exists := metricHashes[hSum]; exists { - return fmt.Errorf( - "collected metric %q { %s} was collected before with the same name and label values", - name, dtoMetric, - ) - } - metricHashes[hSum] = struct{}{} - return nil -} - -func checkDescConsistency( - metricFamily *dto.MetricFamily, - dtoMetric *dto.Metric, - desc *Desc, -) error { - // Desc help consistency with metric family help. - if metricFamily.GetHelp() != desc.help { - return fmt.Errorf( - "collected metric %s %s has help %q but should have %q", - metricFamily.GetName(), dtoMetric, metricFamily.GetHelp(), desc.help, - ) - } - - // Is the desc consistent with the content of the metric? - lpsFromDesc := make([]*dto.LabelPair, len(desc.constLabelPairs), len(dtoMetric.Label)) - copy(lpsFromDesc, desc.constLabelPairs) - for _, l := range desc.variableLabels.names { - lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{ - Name: proto.String(l), - }) - } - if len(lpsFromDesc) != len(dtoMetric.Label) { - return fmt.Errorf( - "labels in collected metric %s %s are inconsistent with descriptor %s", - metricFamily.GetName(), dtoMetric, desc, - ) - } - sort.Sort(internal.LabelPairSorter(lpsFromDesc)) - for i, lpFromDesc := range lpsFromDesc { - lpFromMetric := dtoMetric.Label[i] - if lpFromDesc.GetName() != lpFromMetric.GetName() || - lpFromDesc.Value != nil && lpFromDesc.GetValue() != lpFromMetric.GetValue() { - return fmt.Errorf( - "labels in collected metric %s %s are inconsistent with descriptor %s", - metricFamily.GetName(), dtoMetric, desc, - ) - } - } - return nil -} - -var _ TransactionalGatherer = &MultiTRegistry{} - -// MultiTRegistry is a TransactionalGatherer that joins gathered metrics from multiple -// transactional gatherers. -// -// It is caller responsibility to ensure two registries have mutually exclusive metric families, -// no deduplication will happen. -type MultiTRegistry struct { - tGatherers []TransactionalGatherer -} - -// NewMultiTRegistry creates MultiTRegistry. -func NewMultiTRegistry(tGatherers ...TransactionalGatherer) *MultiTRegistry { - return &MultiTRegistry{ - tGatherers: tGatherers, - } -} - -// Gather implements TransactionalGatherer interface. -func (r *MultiTRegistry) Gather() (mfs []*dto.MetricFamily, done func(), err error) { - errs := MultiError{} - - dFns := make([]func(), 0, len(r.tGatherers)) - // TODO(bwplotka): Implement concurrency for those? - for _, g := range r.tGatherers { - // TODO(bwplotka): Check for duplicates? - m, d, err := g.Gather() - errs.Append(err) - - mfs = append(mfs, m...) - dFns = append(dFns, d) - } - - // TODO(bwplotka): Consider sort in place, given metric family in gather is sorted already. - sort.Slice(mfs, func(i, j int) bool { - return *mfs[i].Name < *mfs[j].Name - }) - return mfs, func() { - for _, d := range dFns { - d() - } - }, errs.MaybeUnwrap() -} - -// TransactionalGatherer represents transactional gatherer that can be triggered to notify gatherer that memory -// used by metric family is no longer used by a caller. This allows implementations with cache. -type TransactionalGatherer interface { - // Gather returns metrics in a lexicographically sorted slice - // of uniquely named MetricFamily protobufs. Gather ensures that the - // returned slice is valid and self-consistent so that it can be used - // for valid exposition. As an exception to the strict consistency - // requirements described for metric.Desc, Gather will tolerate - // different sets of label names for metrics of the same metric family. - // - // Even if an error occurs, Gather attempts to gather as many metrics as - // possible. Hence, if a non-nil error is returned, the returned - // MetricFamily slice could be nil (in case of a fatal error that - // prevented any meaningful metric collection) or contain a number of - // MetricFamily protobufs, some of which might be incomplete, and some - // might be missing altogether. The returned error (which might be a - // MultiError) explains the details. Note that this is mostly useful for - // debugging purposes. If the gathered protobufs are to be used for - // exposition in actual monitoring, it is almost always better to not - // expose an incomplete result and instead disregard the returned - // MetricFamily protobufs in case the returned error is non-nil. - // - // Important: done is expected to be triggered (even if the error occurs!) - // once caller does not need returned slice of dto.MetricFamily. - Gather() (_ []*dto.MetricFamily, done func(), err error) -} - -// ToTransactionalGatherer transforms Gatherer to transactional one with noop as done function. -func ToTransactionalGatherer(g Gatherer) TransactionalGatherer { - return &noTransactionGatherer{g: g} -} - -type noTransactionGatherer struct { - g Gatherer -} - -// Gather implements TransactionalGatherer interface. -func (g *noTransactionGatherer) Gather() (_ []*dto.MetricFamily, done func(), err error) { - mfs, err := g.g.Gather() - return mfs, func() {}, err -} |