diff --git a/cmd/daemon.go b/cmd/daemon.go index 41e6380..d8fee93 100644 --- a/cmd/daemon.go +++ b/cmd/daemon.go @@ -19,8 +19,11 @@ package cmd import ( "git.kolaente.de/sofaraum/client/pkg/processing" + "github.com/prometheus/client_golang/prometheus/promhttp" "github.com/spf13/cobra" "github.com/spf13/viper" + "log" + "net/http" ) // daemonCmd represents the daemon command @@ -29,7 +32,21 @@ var daemonCmd = &cobra.Command{ Short: "Runs the sofa daemon which constantly parses airodump-ng csv dumps and sends the results to the server.", Long: `The sofa daemon parses csv dumps produced by airodump-ng and sends the aggregated results to the sofa server.`, Run: func(cmd *cobra.Command, args []string) { - processing.SummonTheDaemon() + + // Send the daemon process in the background if we want a metrics endpoint + if viper.GetBool("daemon.enableemetricsendpoint") { + go processing.SummonTheDaemon() + + processing.RecordMetrics() + http.Handle("/metrics", promhttp.Handler()) + err := http.ListenAndServe(viper.GetString("daemon.metricsinterface"), nil) + if err != nil { + log.Fatal(err) + } + } else { + // Start the daemon directly + processing.SummonTheDaemon() + } }, } @@ -41,4 +58,9 @@ func init() { viper.BindPFlag("daemon.csvlocation", daemonCmd.Flags().Lookup("csvlocation")) daemonCmd.Flags().StringP("wifidevice", "w", "wlan0", "The wifi interface with which to collect wifi statistics") viper.BindPFlag("daemon.wifidevice", daemonCmd.Flags().Lookup("wifidevice")) + + daemonCmd.Flags().BoolP("metricsendpoint", "m", false, "Enable a /metrics endpoint for prometheus to pull the currently active clients") + viper.BindPFlag("daemon.enableemetricsendpoint", daemonCmd.Flags().Lookup("metricsendpoint")) + daemonCmd.Flags().StringP("metricsinterface", "", ":2112", "The port with interface under which the metrics endpoint should be available") + viper.BindPFlag("daemon.metricsinterface", daemonCmd.Flags().Lookup("metricsinterface")) } diff --git a/cmd/root.go b/cmd/root.go index 4a4da2f..4e529e8 100644 --- a/cmd/root.go +++ b/cmd/root.go @@ -87,6 +87,8 @@ func initConfig() { // Daemon viper.SetDefault("daemon.csvlocation", "") viper.SetDefault("daemon.wifidevice", "wlan0") + viper.SetDefault("daemon.enableemetricsendpoint", false) // Enable a /metrics endpoint for prometheus to get statistics + viper.SetDefault("daemon.metricsinterface", ":2112") // Server viper.SetDefault("server.url", "") viper.SetDefault("server.privatekey", "") diff --git a/pkg/processing/metrics.go b/pkg/processing/metrics.go index bb1ca62..f19160f 100644 --- a/pkg/processing/metrics.go +++ b/pkg/processing/metrics.go @@ -22,7 +22,7 @@ import ( "github.com/prometheus/client_golang/prometheus/promauto" ) -func recordMetrics() { +func RecordMetrics() { go func() { for { activeClients.Set(float64(<-ActiveClients)) diff --git a/pkg/processing/parse_dumps.go b/pkg/processing/parse_dumps.go index 4c43a14..1cc009f 100644 --- a/pkg/processing/parse_dumps.go +++ b/pkg/processing/parse_dumps.go @@ -51,37 +51,39 @@ func ParseCSVDumps(pathToDumps string) (clients []*models.WifiClient) { all := string(bs) i := 0 i = strings.Index(all, config.TheClientCSVHeader) - arefun := all[i+len(config.TheClientCSVHeader)+1:] - arefun = strings.Replace(arefun, " ", "", -1) + if i > 0 { + arefun := all[i+len(config.TheClientCSVHeader)+1:] + arefun = strings.Replace(arefun, " ", "", -1) - scanner := bufio.NewScanner(strings.NewReader(arefun)) - for scanner.Scan() { - r := csv.NewReader(bytes.NewReader(scanner.Bytes())) - record, err := r.Read() - if err != nil { - if err.Error() == "EOF" { - continue + scanner := bufio.NewScanner(strings.NewReader(arefun)) + for scanner.Scan() { + r := csv.NewReader(bytes.NewReader(scanner.Bytes())) + record, err := r.Read() + if err != nil { + if err.Error() == "EOF" { + continue + } + log.Fatal(err) } - log.Fatal(err) - } - power, err := strconv.ParseInt(record[3], 10, 64) - if err != nil { - log.Fatal(err) - } + power, err := strconv.ParseInt(record[3], 10, 64) + if err != nil { + log.Fatal(err) + } - packets, err := strconv.ParseInt(record[4], 10, 64) - if err != nil { - log.Fatal(err) - } + packets, err := strconv.ParseInt(record[4], 10, 64) + if err != nil { + log.Fatal(err) + } - clients = append(clients, &models.WifiClient{ - MACAdress: record[0], - FirstSeen: utils.ParseDateToUnix(record[1]), - LastSeen: utils.ParseDateToUnix(record[2]), - Power: power, - Packets: packets, - }) + clients = append(clients, &models.WifiClient{ + MACAdress: record[0], + FirstSeen: utils.ParseDateToUnix(record[1]), + LastSeen: utils.ParseDateToUnix(record[2]), + Power: power, + Packets: packets, + }) + } } return nil diff --git a/pkg/processing/update_active_clients.go b/pkg/processing/update_active_clients.go index 03a174f..293dada 100644 --- a/pkg/processing/update_active_clients.go +++ b/pkg/processing/update_active_clients.go @@ -18,7 +18,6 @@ package processing import ( - "fmt" "git.kolaente.de/sofaraum/client/pkg/config" "github.com/spf13/viper" "time" @@ -39,7 +38,7 @@ func UpdateActiveClients() { } } ActiveClients <- activeClients - fmt.Println("Active Clients:", activeClients) - fmt.Println("Total Clients:", len(clients)) + //fmt.Println("Active Clients:", activeClients) + //fmt.Println("Total Clients:", len(clients)) } } diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go new file mode 100644 index 0000000..67b56d3 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go @@ -0,0 +1,199 @@ +// Copyright 2017 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 promhttp + +import ( + "bufio" + "io" + "net" + "net/http" +) + +const ( + closeNotifier = 1 << iota + flusher + hijacker + readerFrom + pusher +) + +type delegator interface { + http.ResponseWriter + + Status() int + Written() int64 +} + +type responseWriterDelegator struct { + http.ResponseWriter + + handler, method string + status int + written int64 + wroteHeader bool + observeWriteHeader func(int) +} + +func (r *responseWriterDelegator) Status() int { + return r.status +} + +func (r *responseWriterDelegator) Written() int64 { + return r.written +} + +func (r *responseWriterDelegator) WriteHeader(code int) { + r.status = code + r.wroteHeader = true + r.ResponseWriter.WriteHeader(code) + if r.observeWriteHeader != nil { + r.observeWriteHeader(code) + } +} + +func (r *responseWriterDelegator) Write(b []byte) (int, error) { + if !r.wroteHeader { + r.WriteHeader(http.StatusOK) + } + n, err := r.ResponseWriter.Write(b) + r.written += int64(n) + return n, err +} + +type closeNotifierDelegator struct{ *responseWriterDelegator } +type flusherDelegator struct{ *responseWriterDelegator } +type hijackerDelegator struct{ *responseWriterDelegator } +type readerFromDelegator struct{ *responseWriterDelegator } + +func (d closeNotifierDelegator) CloseNotify() <-chan bool { + return d.ResponseWriter.(http.CloseNotifier).CloseNotify() +} +func (d flusherDelegator) Flush() { + d.ResponseWriter.(http.Flusher).Flush() +} +func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) { + return d.ResponseWriter.(http.Hijacker).Hijack() +} +func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) { + if !d.wroteHeader { + d.WriteHeader(http.StatusOK) + } + n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re) + d.written += n + return n, err +} + +var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32) + +func init() { + // TODO(beorn7): Code generation would help here. + pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0 + return d + } + pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1 + return closeNotifierDelegator{d} + } + pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2 + return flusherDelegator{d} + } + pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3 + return struct { + *responseWriterDelegator + http.Flusher + http.CloseNotifier + }{d, flusherDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4 + return hijackerDelegator{d} + } + pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5 + return struct { + *responseWriterDelegator + http.Hijacker + http.CloseNotifier + }{d, hijackerDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6 + return struct { + *responseWriterDelegator + http.Hijacker + http.Flusher + }{d, hijackerDelegator{d}, flusherDelegator{d}} + } + pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7 + return struct { + *responseWriterDelegator + http.Hijacker + http.Flusher + http.CloseNotifier + }{d, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8 + return readerFromDelegator{d} + } + pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9 + return struct { + *responseWriterDelegator + io.ReaderFrom + http.CloseNotifier + }{d, readerFromDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10 + return struct { + *responseWriterDelegator + io.ReaderFrom + http.Flusher + }{d, readerFromDelegator{d}, flusherDelegator{d}} + } + pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11 + return struct { + *responseWriterDelegator + io.ReaderFrom + http.Flusher + http.CloseNotifier + }{d, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12 + return struct { + *responseWriterDelegator + io.ReaderFrom + http.Hijacker + }{d, readerFromDelegator{d}, hijackerDelegator{d}} + } + pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13 + return struct { + *responseWriterDelegator + io.ReaderFrom + http.Hijacker + http.CloseNotifier + }{d, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14 + return struct { + *responseWriterDelegator + io.ReaderFrom + http.Hijacker + http.Flusher + }{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}} + } + pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15 + return struct { + *responseWriterDelegator + io.ReaderFrom + http.Hijacker + http.Flusher + http.CloseNotifier + }{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}} + } +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go new file mode 100644 index 0000000..31a7069 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go @@ -0,0 +1,181 @@ +// Copyright 2017 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 go1.8 + +package promhttp + +import ( + "io" + "net/http" +) + +type pusherDelegator struct{ *responseWriterDelegator } + +func (d pusherDelegator) Push(target string, opts *http.PushOptions) error { + return d.ResponseWriter.(http.Pusher).Push(target, opts) +} + +func init() { + pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16 + return pusherDelegator{d} + } + pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17 + return struct { + *responseWriterDelegator + http.Pusher + http.CloseNotifier + }{d, pusherDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18 + return struct { + *responseWriterDelegator + http.Pusher + http.Flusher + }{d, pusherDelegator{d}, flusherDelegator{d}} + } + pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19 + return struct { + *responseWriterDelegator + http.Pusher + http.Flusher + http.CloseNotifier + }{d, pusherDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20 + return struct { + *responseWriterDelegator + http.Pusher + http.Hijacker + }{d, pusherDelegator{d}, hijackerDelegator{d}} + } + pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21 + return struct { + *responseWriterDelegator + http.Pusher + http.Hijacker + http.CloseNotifier + }{d, pusherDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22 + return struct { + *responseWriterDelegator + http.Pusher + http.Hijacker + http.Flusher + }{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}} + } + pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { //23 + return struct { + *responseWriterDelegator + http.Pusher + http.Hijacker + http.Flusher + http.CloseNotifier + }{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + }{d, pusherDelegator{d}, readerFromDelegator{d}} + } + pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + http.CloseNotifier + }{d, pusherDelegator{d}, readerFromDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + http.Flusher + }{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}} + } + pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + http.Flusher + http.CloseNotifier + }{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + http.Hijacker + }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}} + } + pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + http.Hijacker + http.CloseNotifier + }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}} + } + pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + http.Hijacker + http.Flusher + }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}} + } + pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31 + return struct { + *responseWriterDelegator + http.Pusher + io.ReaderFrom + http.Hijacker + http.Flusher + http.CloseNotifier + }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}} + } +} + +func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator { + d := &responseWriterDelegator{ + ResponseWriter: w, + observeWriteHeader: observeWriteHeaderFunc, + } + + id := 0 + if _, ok := w.(http.CloseNotifier); ok { + id += closeNotifier + } + if _, ok := w.(http.Flusher); ok { + id += flusher + } + if _, ok := w.(http.Hijacker); ok { + id += hijacker + } + if _, ok := w.(io.ReaderFrom); ok { + id += readerFrom + } + if _, ok := w.(http.Pusher); ok { + id += pusher + } + + return pickDelegator[id](d) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_pre_1_8.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_pre_1_8.go new file mode 100644 index 0000000..8bb9b8b --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_pre_1_8.go @@ -0,0 +1,44 @@ +// Copyright 2017 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 !go1.8 + +package promhttp + +import ( + "io" + "net/http" +) + +func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator { + d := &responseWriterDelegator{ + ResponseWriter: w, + observeWriteHeader: observeWriteHeaderFunc, + } + + id := 0 + if _, ok := w.(http.CloseNotifier); ok { + id += closeNotifier + } + if _, ok := w.(http.Flusher); ok { + id += flusher + } + if _, ok := w.(http.Hijacker); ok { + id += hijacker + } + if _, ok := w.(io.ReaderFrom); ok { + id += readerFrom + } + + return pickDelegator[id](d) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go new file mode 100644 index 0000000..668eb6b --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go @@ -0,0 +1,311 @@ +// Copyright 2016 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 promhttp provides tooling around HTTP servers and clients. +// +// First, the package allows the creation of http.Handler instances to expose +// Prometheus metrics via HTTP. promhttp.Handler acts on the +// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a +// custom registry or anything that implements the Gatherer interface. It also +// allows the creation of handlers that act differently on errors or allow to +// log errors. +// +// Second, the package provides tooling to instrument instances of http.Handler +// via middleware. Middleware wrappers follow the naming scheme +// InstrumentHandlerX, where X describes the intended use of the middleware. +// See each function's doc comment for specific details. +// +// Finally, the package allows for an http.RoundTripper to be instrumented via +// middleware. Middleware wrappers follow the naming scheme +// InstrumentRoundTripperX, where X describes the intended use of the +// middleware. See each function's doc comment for specific details. +package promhttp + +import ( + "compress/gzip" + "fmt" + "io" + "net/http" + "strings" + "sync" + "time" + + "github.com/prometheus/common/expfmt" + + "github.com/prometheus/client_golang/prometheus" +) + +const ( + contentTypeHeader = "Content-Type" + contentLengthHeader = "Content-Length" + contentEncodingHeader = "Content-Encoding" + acceptEncodingHeader = "Accept-Encoding" +) + +var gzipPool = sync.Pool{ + New: func() interface{} { + return gzip.NewWriter(nil) + }, +} + +// Handler returns an http.Handler for the prometheus.DefaultGatherer, using +// default HandlerOpts, i.e. it reports the first error as an HTTP error, it has +// no error logging, and it applies compression if requested by the client. +// +// The returned http.Handler is already instrumented using the +// InstrumentMetricHandler function and the prometheus.DefaultRegisterer. If you +// create multiple http.Handlers by separate calls of the Handler function, the +// metrics used for instrumentation will be shared between them, providing +// global scrape counts. +// +// This function is meant to cover the bulk of basic use cases. If you are doing +// anything that requires more customization (including using a non-default +// Gatherer, different instrumentation, and non-default HandlerOpts), use the +// HandlerFor function. See there for details. +func Handler() http.Handler { + return InstrumentMetricHandler( + prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}), + ) +} + +// HandlerFor returns an uninstrumented http.Handler for the provided +// Gatherer. The behavior of the Handler is defined by the provided +// HandlerOpts. Thus, HandlerFor is useful to create http.Handlers for custom +// Gatherers, with non-default HandlerOpts, and/or with custom (or no) +// instrumentation. Use the InstrumentMetricHandler function to apply the same +// kind of instrumentation as it is used by the Handler function. +func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler { + var inFlightSem chan struct{} + if opts.MaxRequestsInFlight > 0 { + inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight) + } + + h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) { + if inFlightSem != nil { + select { + case inFlightSem <- struct{}{}: // All good, carry on. + defer func() { <-inFlightSem }() + default: + http.Error(rsp, fmt.Sprintf( + "Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight, + ), http.StatusServiceUnavailable) + return + } + } + mfs, err := reg.Gather() + if err != nil { + if opts.ErrorLog != nil { + opts.ErrorLog.Println("error gathering metrics:", err) + } + switch opts.ErrorHandling { + case PanicOnError: + panic(err) + case ContinueOnError: + if len(mfs) == 0 { + // Still report the error if no metrics have been gathered. + httpError(rsp, err) + return + } + case HTTPErrorOnError: + httpError(rsp, err) + return + } + } + + contentType := expfmt.Negotiate(req.Header) + header := rsp.Header() + header.Set(contentTypeHeader, string(contentType)) + + w := io.Writer(rsp) + if !opts.DisableCompression && gzipAccepted(req.Header) { + header.Set(contentEncodingHeader, "gzip") + gz := gzipPool.Get().(*gzip.Writer) + defer gzipPool.Put(gz) + + gz.Reset(w) + defer gz.Close() + + w = gz + } + + enc := expfmt.NewEncoder(w, contentType) + + var lastErr error + for _, mf := range mfs { + if err := enc.Encode(mf); err != nil { + lastErr = err + if opts.ErrorLog != nil { + opts.ErrorLog.Println("error encoding and sending metric family:", err) + } + switch opts.ErrorHandling { + case PanicOnError: + panic(err) + case ContinueOnError: + // Handled later. + case HTTPErrorOnError: + httpError(rsp, err) + return + } + } + } + + if lastErr != nil { + httpError(rsp, lastErr) + } + }) + + if opts.Timeout <= 0 { + return h + } + return http.TimeoutHandler(h, opts.Timeout, fmt.Sprintf( + "Exceeded configured timeout of %v.\n", + opts.Timeout, + )) +} + +// InstrumentMetricHandler is usually used with an http.Handler returned by the +// HandlerFor function. It instruments the provided http.Handler with two +// metrics: A counter vector "promhttp_metric_handler_requests_total" to count +// scrapes partitioned by HTTP status code, and a gauge +// "promhttp_metric_handler_requests_in_flight" to track the number of +// simultaneous scrapes. This function idempotently registers collectors for +// both metrics with the provided Registerer. It panics if the registration +// fails. The provided metrics are useful to see how many scrapes hit the +// monitored target (which could be from different Prometheus servers or other +// scrapers), and how often they overlap (which would result in more than one +// scrape in flight at the same time). Note that the scrapes-in-flight gauge +// will contain the scrape by which it is exposed, while the scrape counter will +// only get incremented after the scrape is complete (as only then the status +// code is known). For tracking scrape durations, use the +// "scrape_duration_seconds" gauge created by the Prometheus server upon each +// scrape. +func InstrumentMetricHandler(reg prometheus.Registerer, handler http.Handler) http.Handler { + cnt := prometheus.NewCounterVec( + prometheus.CounterOpts{ + Name: "promhttp_metric_handler_requests_total", + Help: "Total number of scrapes by HTTP status code.", + }, + []string{"code"}, + ) + // Initialize the most likely HTTP status codes. + cnt.WithLabelValues("200") + cnt.WithLabelValues("500") + cnt.WithLabelValues("503") + if err := reg.Register(cnt); err != nil { + if are, ok := err.(prometheus.AlreadyRegisteredError); ok { + cnt = are.ExistingCollector.(*prometheus.CounterVec) + } else { + panic(err) + } + } + + gge := prometheus.NewGauge(prometheus.GaugeOpts{ + Name: "promhttp_metric_handler_requests_in_flight", + Help: "Current number of scrapes being served.", + }) + if err := reg.Register(gge); err != nil { + if are, ok := err.(prometheus.AlreadyRegisteredError); ok { + gge = are.ExistingCollector.(prometheus.Gauge) + } else { + panic(err) + } + } + + return InstrumentHandlerCounter(cnt, InstrumentHandlerInFlight(gge, handler)) +} + +// HandlerErrorHandling defines how a Handler serving metrics will handle +// errors. +type HandlerErrorHandling int + +// These constants cause handlers serving metrics to behave as described if +// errors are encountered. +const ( + // Serve an HTTP status code 500 upon the first error + // encountered. Report the error message in the body. + HTTPErrorOnError HandlerErrorHandling = iota + // Ignore errors and try to serve as many metrics as possible. However, + // if no metrics can be served, serve an HTTP status code 500 and the + // last error message in the body. Only use this in deliberate "best + // effort" metrics collection scenarios. It is recommended to at least + // log errors (by providing an ErrorLog in HandlerOpts) to not mask + // errors completely. + ContinueOnError + // Panic upon the first error encountered (useful for "crash only" apps). + PanicOnError +) + +// Logger is the minimal interface HandlerOpts needs for logging. Note that +// log.Logger from the standard library implements this interface, and it is +// easy to implement by custom loggers, if they don't do so already anyway. +type Logger interface { + Println(v ...interface{}) +} + +// HandlerOpts specifies options how to serve metrics via an http.Handler. The +// zero value of HandlerOpts is a reasonable default. +type HandlerOpts struct { + // ErrorLog specifies an optional logger for errors collecting and + // serving metrics. If nil, errors are not logged at all. + ErrorLog Logger + // ErrorHandling defines how errors are handled. Note that errors are + // logged regardless of the configured ErrorHandling provided ErrorLog + // is not nil. + ErrorHandling HandlerErrorHandling + // If DisableCompression is true, the handler will never compress the + // response, even if requested by the client. + DisableCompression bool + // The number of concurrent HTTP requests is limited to + // MaxRequestsInFlight. Additional requests are responded to with 503 + // Service Unavailable and a suitable message in the body. If + // MaxRequestsInFlight is 0 or negative, no limit is applied. + MaxRequestsInFlight int + // If handling a request takes longer than Timeout, it is responded to + // with 503 ServiceUnavailable and a suitable Message. No timeout is + // applied if Timeout is 0 or negative. Note that with the current + // implementation, reaching the timeout simply ends the HTTP requests as + // described above (and even that only if sending of the body hasn't + // started yet), while the bulk work of gathering all the metrics keeps + // running in the background (with the eventual result to be thrown + // away). Until the implementation is improved, it is recommended to + // implement a separate timeout in potentially slow Collectors. + Timeout time.Duration +} + +// gzipAccepted returns whether the client will accept gzip-encoded content. +func gzipAccepted(header http.Header) bool { + a := header.Get(acceptEncodingHeader) + parts := strings.Split(a, ",") + for _, part := range parts { + part = strings.TrimSpace(part) + if part == "gzip" || strings.HasPrefix(part, "gzip;") { + return true + } + } + return false +} + +// httpError removes any content-encoding header and then calls http.Error with +// the provided error and http.StatusInternalServerErrer. Error contents is +// supposed to be uncompressed plain text. However, same as with a plain +// http.Error, any header settings will be void if the header has already been +// sent. The error message will still be written to the writer, but it will +// probably be of limited use. +func httpError(rsp http.ResponseWriter, err error) { + rsp.Header().Del(contentEncodingHeader) + http.Error( + rsp, + "An error has occurred while serving metrics:\n\n"+err.Error(), + http.StatusInternalServerError, + ) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go new file mode 100644 index 0000000..86fd564 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go @@ -0,0 +1,97 @@ +// Copyright 2017 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 promhttp + +import ( + "net/http" + "time" + + "github.com/prometheus/client_golang/prometheus" +) + +// The RoundTripperFunc type is an adapter to allow the use of ordinary +// functions as RoundTrippers. If f is a function with the appropriate +// signature, RountTripperFunc(f) is a RoundTripper that calls f. +type RoundTripperFunc func(req *http.Request) (*http.Response, error) + +// RoundTrip implements the RoundTripper interface. +func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) { + return rt(r) +} + +// InstrumentRoundTripperInFlight is a middleware that wraps the provided +// http.RoundTripper. It sets the provided prometheus.Gauge to the number of +// requests currently handled by the wrapped http.RoundTripper. +// +// See the example for ExampleInstrumentRoundTripperDuration for example usage. +func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc { + return RoundTripperFunc(func(r *http.Request) (*http.Response, error) { + gauge.Inc() + defer gauge.Dec() + return next.RoundTrip(r) + }) +} + +// InstrumentRoundTripperCounter is a middleware that wraps the provided +// http.RoundTripper to observe the request result with the provided CounterVec. +// The CounterVec must have zero, one, or two non-const non-curried labels. For +// those, the only allowed label names are "code" and "method". The function +// panics otherwise. Partitioning of the CounterVec happens by HTTP status code +// and/or HTTP method if the respective instance label names are present in the +// CounterVec. For unpartitioned counting, use a CounterVec with zero labels. +// +// If the wrapped RoundTripper panics or returns a non-nil error, the Counter +// is not incremented. +// +// See the example for ExampleInstrumentRoundTripperDuration for example usage. +func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper) RoundTripperFunc { + code, method := checkLabels(counter) + + return RoundTripperFunc(func(r *http.Request) (*http.Response, error) { + resp, err := next.RoundTrip(r) + if err == nil { + counter.With(labels(code, method, r.Method, resp.StatusCode)).Inc() + } + return resp, err + }) +} + +// InstrumentRoundTripperDuration is a middleware that wraps the provided +// http.RoundTripper to observe the request duration with the provided +// ObserverVec. The ObserverVec must have zero, one, or two non-const +// non-curried labels. For those, the only allowed label names are "code" and +// "method". The function panics otherwise. The Observe method of the Observer +// in the ObserverVec is called with the request duration in +// seconds. Partitioning happens by HTTP status code and/or HTTP method if the +// respective instance label names are present in the ObserverVec. For +// unpartitioned observations, use an ObserverVec with zero labels. Note that +// partitioning of Histograms is expensive and should be used judiciously. +// +// If the wrapped RoundTripper panics or returns a non-nil error, no values are +// reported. +// +// Note that this method is only guaranteed to never observe negative durations +// if used with Go1.9+. +func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper) RoundTripperFunc { + code, method := checkLabels(obs) + + return RoundTripperFunc(func(r *http.Request) (*http.Response, error) { + start := time.Now() + resp, err := next.RoundTrip(r) + if err == nil { + obs.With(labels(code, method, r.Method, resp.StatusCode)).Observe(time.Since(start).Seconds()) + } + return resp, err + }) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8.go new file mode 100644 index 0000000..a034d1e --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8.go @@ -0,0 +1,144 @@ +// Copyright 2017 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 go1.8 + +package promhttp + +import ( + "context" + "crypto/tls" + "net/http" + "net/http/httptrace" + "time" +) + +// InstrumentTrace is used to offer flexibility in instrumenting the available +// httptrace.ClientTrace hook functions. Each function is passed a float64 +// representing the time in seconds since the start of the http request. A user +// may choose to use separately buckets Histograms, or implement custom +// instance labels on a per function basis. +type InstrumentTrace struct { + GotConn func(float64) + PutIdleConn func(float64) + GotFirstResponseByte func(float64) + Got100Continue func(float64) + DNSStart func(float64) + DNSDone func(float64) + ConnectStart func(float64) + ConnectDone func(float64) + TLSHandshakeStart func(float64) + TLSHandshakeDone func(float64) + WroteHeaders func(float64) + Wait100Continue func(float64) + WroteRequest func(float64) +} + +// InstrumentRoundTripperTrace is a middleware that wraps the provided +// RoundTripper and reports times to hook functions provided in the +// InstrumentTrace struct. Hook functions that are not present in the provided +// InstrumentTrace struct are ignored. Times reported to the hook functions are +// time since the start of the request. Only with Go1.9+, those times are +// guaranteed to never be negative. (Earlier Go versions are not using a +// monotonic clock.) Note that partitioning of Histograms is expensive and +// should be used judiciously. +// +// For hook functions that receive an error as an argument, no observations are +// made in the event of a non-nil error value. +// +// See the example for ExampleInstrumentRoundTripperDuration for example usage. +func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc { + return RoundTripperFunc(func(r *http.Request) (*http.Response, error) { + start := time.Now() + + trace := &httptrace.ClientTrace{ + GotConn: func(_ httptrace.GotConnInfo) { + if it.GotConn != nil { + it.GotConn(time.Since(start).Seconds()) + } + }, + PutIdleConn: func(err error) { + if err != nil { + return + } + if it.PutIdleConn != nil { + it.PutIdleConn(time.Since(start).Seconds()) + } + }, + DNSStart: func(_ httptrace.DNSStartInfo) { + if it.DNSStart != nil { + it.DNSStart(time.Since(start).Seconds()) + } + }, + DNSDone: func(_ httptrace.DNSDoneInfo) { + if it.DNSDone != nil { + it.DNSDone(time.Since(start).Seconds()) + } + }, + ConnectStart: func(_, _ string) { + if it.ConnectStart != nil { + it.ConnectStart(time.Since(start).Seconds()) + } + }, + ConnectDone: func(_, _ string, err error) { + if err != nil { + return + } + if it.ConnectDone != nil { + it.ConnectDone(time.Since(start).Seconds()) + } + }, + GotFirstResponseByte: func() { + if it.GotFirstResponseByte != nil { + it.GotFirstResponseByte(time.Since(start).Seconds()) + } + }, + Got100Continue: func() { + if it.Got100Continue != nil { + it.Got100Continue(time.Since(start).Seconds()) + } + }, + TLSHandshakeStart: func() { + if it.TLSHandshakeStart != nil { + it.TLSHandshakeStart(time.Since(start).Seconds()) + } + }, + TLSHandshakeDone: func(_ tls.ConnectionState, err error) { + if err != nil { + return + } + if it.TLSHandshakeDone != nil { + it.TLSHandshakeDone(time.Since(start).Seconds()) + } + }, + WroteHeaders: func() { + if it.WroteHeaders != nil { + it.WroteHeaders(time.Since(start).Seconds()) + } + }, + Wait100Continue: func() { + if it.Wait100Continue != nil { + it.Wait100Continue(time.Since(start).Seconds()) + } + }, + WroteRequest: func(_ httptrace.WroteRequestInfo) { + if it.WroteRequest != nil { + it.WroteRequest(time.Since(start).Seconds()) + } + }, + } + r = r.WithContext(httptrace.WithClientTrace(context.Background(), trace)) + + return next.RoundTrip(r) + }) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go new file mode 100644 index 0000000..9db2438 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go @@ -0,0 +1,447 @@ +// Copyright 2017 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 promhttp + +import ( + "errors" + "net/http" + "strconv" + "strings" + "time" + + dto "github.com/prometheus/client_model/go" + + "github.com/prometheus/client_golang/prometheus" +) + +// magicString is used for the hacky label test in checkLabels. Remove once fixed. +const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa" + +// InstrumentHandlerInFlight is a middleware that wraps the provided +// http.Handler. It sets the provided prometheus.Gauge to the number of +// requests currently handled by the wrapped http.Handler. +// +// See the example for InstrumentHandlerDuration for example usage. +func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler { + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + g.Inc() + defer g.Dec() + next.ServeHTTP(w, r) + }) +} + +// InstrumentHandlerDuration is a middleware that wraps the provided +// http.Handler to observe the request duration with the provided ObserverVec. +// The ObserverVec must have zero, one, or two non-const non-curried labels. For +// those, the only allowed label names are "code" and "method". The function +// panics otherwise. The Observe method of the Observer in the ObserverVec is +// called with the request duration in seconds. Partitioning happens by HTTP +// status code and/or HTTP method if the respective instance label names are +// present in the ObserverVec. For unpartitioned observations, use an +// ObserverVec with zero labels. Note that partitioning of Histograms is +// expensive and should be used judiciously. +// +// If the wrapped Handler does not set a status code, a status code of 200 is assumed. +// +// If the wrapped Handler panics, no values are reported. +// +// Note that this method is only guaranteed to never observe negative durations +// if used with Go1.9+. +func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc { + code, method := checkLabels(obs) + + if code { + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + now := time.Now() + d := newDelegator(w, nil) + next.ServeHTTP(d, r) + + obs.With(labels(code, method, r.Method, d.Status())).Observe(time.Since(now).Seconds()) + }) + } + + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + now := time.Now() + next.ServeHTTP(w, r) + obs.With(labels(code, method, r.Method, 0)).Observe(time.Since(now).Seconds()) + }) +} + +// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler +// to observe the request result with the provided CounterVec. The CounterVec +// must have zero, one, or two non-const non-curried labels. For those, the only +// allowed label names are "code" and "method". The function panics +// otherwise. Partitioning of the CounterVec happens by HTTP status code and/or +// HTTP method if the respective instance label names are present in the +// CounterVec. For unpartitioned counting, use a CounterVec with zero labels. +// +// If the wrapped Handler does not set a status code, a status code of 200 is assumed. +// +// If the wrapped Handler panics, the Counter is not incremented. +// +// See the example for InstrumentHandlerDuration for example usage. +func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) http.HandlerFunc { + code, method := checkLabels(counter) + + if code { + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + d := newDelegator(w, nil) + next.ServeHTTP(d, r) + counter.With(labels(code, method, r.Method, d.Status())).Inc() + }) + } + + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + next.ServeHTTP(w, r) + counter.With(labels(code, method, r.Method, 0)).Inc() + }) +} + +// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided +// http.Handler to observe with the provided ObserverVec the request duration +// until the response headers are written. The ObserverVec must have zero, one, +// or two non-const non-curried labels. For those, the only allowed label names +// are "code" and "method". The function panics otherwise. The Observe method of +// the Observer in the ObserverVec is called with the request duration in +// seconds. Partitioning happens by HTTP status code and/or HTTP method if the +// respective instance label names are present in the ObserverVec. For +// unpartitioned observations, use an ObserverVec with zero labels. Note that +// partitioning of Histograms is expensive and should be used judiciously. +// +// If the wrapped Handler panics before calling WriteHeader, no value is +// reported. +// +// Note that this method is only guaranteed to never observe negative durations +// if used with Go1.9+. +// +// See the example for InstrumentHandlerDuration for example usage. +func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc { + code, method := checkLabels(obs) + + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + now := time.Now() + d := newDelegator(w, func(status int) { + obs.With(labels(code, method, r.Method, status)).Observe(time.Since(now).Seconds()) + }) + next.ServeHTTP(d, r) + }) +} + +// InstrumentHandlerRequestSize is a middleware that wraps the provided +// http.Handler to observe the request size with the provided ObserverVec. The +// ObserverVec must have zero, one, or two non-const non-curried labels. For +// those, the only allowed label names are "code" and "method". The function +// panics otherwise. The Observe method of the Observer in the ObserverVec is +// called with the request size in bytes. Partitioning happens by HTTP status +// code and/or HTTP method if the respective instance label names are present in +// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero +// labels. Note that partitioning of Histograms is expensive and should be used +// judiciously. +// +// If the wrapped Handler does not set a status code, a status code of 200 is assumed. +// +// If the wrapped Handler panics, no values are reported. +// +// See the example for InstrumentHandlerDuration for example usage. +func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc { + code, method := checkLabels(obs) + + if code { + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + d := newDelegator(w, nil) + next.ServeHTTP(d, r) + size := computeApproximateRequestSize(r) + obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(size)) + }) + } + + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + next.ServeHTTP(w, r) + size := computeApproximateRequestSize(r) + obs.With(labels(code, method, r.Method, 0)).Observe(float64(size)) + }) +} + +// InstrumentHandlerResponseSize is a middleware that wraps the provided +// http.Handler to observe the response size with the provided ObserverVec. The +// ObserverVec must have zero, one, or two non-const non-curried labels. For +// those, the only allowed label names are "code" and "method". The function +// panics otherwise. The Observe method of the Observer in the ObserverVec is +// called with the response size in bytes. Partitioning happens by HTTP status +// code and/or HTTP method if the respective instance label names are present in +// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero +// labels. Note that partitioning of Histograms is expensive and should be used +// judiciously. +// +// If the wrapped Handler does not set a status code, a status code of 200 is assumed. +// +// If the wrapped Handler panics, no values are reported. +// +// See the example for InstrumentHandlerDuration for example usage. +func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler) http.Handler { + code, method := checkLabels(obs) + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + d := newDelegator(w, nil) + next.ServeHTTP(d, r) + obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(d.Written())) + }) +} + +func checkLabels(c prometheus.Collector) (code bool, method bool) { + // TODO(beorn7): Remove this hacky way to check for instance labels + // once Descriptors can have their dimensionality queried. + var ( + desc *prometheus.Desc + m prometheus.Metric + pm dto.Metric + lvs []string + ) + + // Get the Desc from the Collector. + descc := make(chan *prometheus.Desc, 1) + c.Describe(descc) + + select { + case desc = <-descc: + default: + panic("no description provided by collector") + } + select { + case <-descc: + panic("more than one description provided by collector") + default: + } + + close(descc) + + // Create a ConstMetric with the Desc. Since we don't know how many + // variable labels there are, try for as long as it needs. + for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) { + m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...) + } + + // Write out the metric into a proto message and look at the labels. + // If the value is not the magicString, it is a constLabel, which doesn't interest us. + // If the label is curried, it doesn't interest us. + // In all other cases, only "code" or "method" is allowed. + if err := m.Write(&pm); err != nil { + panic("error checking metric for labels") + } + for _, label := range pm.Label { + name, value := label.GetName(), label.GetValue() + if value != magicString || isLabelCurried(c, name) { + continue + } + switch name { + case "code": + code = true + case "method": + method = true + default: + panic("metric partitioned with non-supported labels") + } + } + return +} + +func isLabelCurried(c prometheus.Collector, label string) bool { + // This is even hackier than the label test above. + // We essentially try to curry again and see if it works. + // But for that, we need to type-convert to the two + // types we use here, ObserverVec or *CounterVec. + switch v := c.(type) { + case *prometheus.CounterVec: + if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil { + return false + } + case prometheus.ObserverVec: + if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil { + return false + } + default: + panic("unsupported metric vec type") + } + return true +} + +// emptyLabels is a one-time allocation for non-partitioned metrics to avoid +// unnecessary allocations on each request. +var emptyLabels = prometheus.Labels{} + +func labels(code, method bool, reqMethod string, status int) prometheus.Labels { + if !(code || method) { + return emptyLabels + } + labels := prometheus.Labels{} + + if code { + labels["code"] = sanitizeCode(status) + } + if method { + labels["method"] = sanitizeMethod(reqMethod) + } + + return labels +} + +func computeApproximateRequestSize(r *http.Request) int { + s := 0 + if r.URL != nil { + s += len(r.URL.String()) + } + + s += len(r.Method) + s += len(r.Proto) + for name, values := range r.Header { + s += len(name) + for _, value := range values { + s += len(value) + } + } + s += len(r.Host) + + // N.B. r.Form and r.MultipartForm are assumed to be included in r.URL. + + if r.ContentLength != -1 { + s += int(r.ContentLength) + } + return s +} + +func sanitizeMethod(m string) string { + switch m { + case "GET", "get": + return "get" + case "PUT", "put": + return "put" + case "HEAD", "head": + return "head" + case "POST", "post": + return "post" + case "DELETE", "delete": + return "delete" + case "CONNECT", "connect": + return "connect" + case "OPTIONS", "options": + return "options" + case "NOTIFY", "notify": + return "notify" + default: + return strings.ToLower(m) + } +} + +// If the wrapped http.Handler has not set a status code, i.e. the value is +// currently 0, santizeCode will return 200, for consistency with behavior in +// the stdlib. +func sanitizeCode(s int) string { + switch s { + case 100: + return "100" + case 101: + return "101" + + case 200, 0: + return "200" + case 201: + return "201" + case 202: + return "202" + case 203: + return "203" + case 204: + return "204" + case 205: + return "205" + case 206: + return "206" + + case 300: + return "300" + case 301: + return "301" + case 302: + return "302" + case 304: + return "304" + case 305: + return "305" + case 307: + return "307" + + case 400: + return "400" + case 401: + return "401" + case 402: + return "402" + case 403: + return "403" + case 404: + return "404" + case 405: + return "405" + case 406: + return "406" + case 407: + return "407" + case 408: + return "408" + case 409: + return "409" + case 410: + return "410" + case 411: + return "411" + case 412: + return "412" + case 413: + return "413" + case 414: + return "414" + case 415: + return "415" + case 416: + return "416" + case 417: + return "417" + case 418: + return "418" + + case 500: + return "500" + case 501: + return "501" + case 502: + return "502" + case 503: + return "503" + case 504: + return "504" + case 505: + return "505" + + case 428: + return "428" + case 429: + return "429" + case 431: + return "431" + case 511: + return "511" + + default: + return strconv.Itoa(s) + } +} diff --git a/vendor/modules.txt b/vendor/modules.txt index 6d539da..dbab2ee 100644 --- a/vendor/modules.txt +++ b/vendor/modules.txt @@ -37,6 +37,7 @@ github.com/mitchellh/mapstructure # github.com/pelletier/go-toml v1.2.0 github.com/pelletier/go-toml # github.com/prometheus/client_golang v0.9.2 +github.com/prometheus/client_golang/prometheus/promhttp github.com/prometheus/client_golang/prometheus github.com/prometheus/client_golang/prometheus/promauto github.com/prometheus/client_golang/prometheus/internal