Dependencies for the affinity router and the
affinity routing daemon.
Change-Id: Icda72c3594ef7f8f0bc0c33dc03087a4c25529ca
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/http.go b/vendor/github.com/prometheus/client_golang/prometheus/http.go
new file mode 100644
index 0000000..9f0875b
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/http.go
@@ -0,0 +1,504 @@
+// 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 (
+ "bufio"
+ "compress/gzip"
+ "io"
+ "net"
+ "net/http"
+ "strconv"
+ "strings"
+ "sync"
+ "time"
+
+ "github.com/prometheus/common/expfmt"
+)
+
+// TODO(beorn7): Remove this whole file. It is a partial mirror of
+// promhttp/http.go (to avoid circular import chains) where everything HTTP
+// related should live. The functions here are just for avoiding
+// breakage. Everything is deprecated.
+
+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 DefaultGatherer. It is
+// already instrumented with InstrumentHandler (using "prometheus" as handler
+// name).
+//
+// Deprecated: Please note the issues described in the doc comment of
+// InstrumentHandler. You might want to consider using promhttp.Handler instead.
+func Handler() http.Handler {
+ return InstrumentHandler("prometheus", UninstrumentedHandler())
+}
+
+// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
+//
+// Deprecated: Use promhttp.HandlerFor(DefaultGatherer, promhttp.HandlerOpts{})
+// instead. See there for further documentation.
+func UninstrumentedHandler() http.Handler {
+ return http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
+ mfs, err := DefaultGatherer.Gather()
+ if err != nil {
+ httpError(rsp, err)
+ return
+ }
+
+ contentType := expfmt.Negotiate(req.Header)
+ header := rsp.Header()
+ header.Set(contentTypeHeader, string(contentType))
+
+ w := io.Writer(rsp)
+ if 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)
+
+ for _, mf := range mfs {
+ if err := enc.Encode(mf); err != nil {
+ httpError(rsp, err)
+ return
+ }
+ }
+ })
+}
+
+var instLabels = []string{"method", "code"}
+
+type nower interface {
+ Now() time.Time
+}
+
+type nowFunc func() time.Time
+
+func (n nowFunc) Now() time.Time {
+ return n()
+}
+
+var now nower = nowFunc(func() time.Time {
+ return time.Now()
+})
+
+// InstrumentHandler wraps the given HTTP handler for instrumentation. It
+// registers four metric collectors (if not already done) and reports HTTP
+// metrics to the (newly or already) registered collectors: http_requests_total
+// (CounterVec), http_request_duration_microseconds (Summary),
+// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
+// has a constant label named "handler" with the provided handlerName as
+// value. http_requests_total is a metric vector partitioned by HTTP method
+// (label name "method") and HTTP status code (label name "code").
+//
+// Deprecated: InstrumentHandler has several issues. Use the tooling provided in
+// package promhttp instead. The issues are the following: (1) It uses Summaries
+// rather than Histograms. Summaries are not useful if aggregation across
+// multiple instances is required. (2) It uses microseconds as unit, which is
+// deprecated and should be replaced by seconds. (3) The size of the request is
+// calculated in a separate goroutine. Since this calculator requires access to
+// the request header, it creates a race with any writes to the header performed
+// during request handling. httputil.ReverseProxy is a prominent example for a
+// handler performing such writes. (4) It has additional issues with HTTP/2, cf.
+// https://github.com/prometheus/client_golang/issues/272.
+func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
+ return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFunc wraps the given function for instrumentation. It
+// otherwise works in the same way as InstrumentHandler (and shares the same
+// issues).
+//
+// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
+// InstrumentHandler is. Use the tooling provided in package promhttp instead.
+func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+ return InstrumentHandlerFuncWithOpts(
+ SummaryOpts{
+ Subsystem: "http",
+ ConstLabels: Labels{"handler": handlerName},
+ Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+ },
+ handlerFunc,
+ )
+}
+
+// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
+// issues) but provides more flexibility (at the cost of a more complex call
+// syntax). As InstrumentHandler, this function registers four metric
+// collectors, but it uses the provided SummaryOpts to create them. However, the
+// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
+// by "requests_total", "request_duration_microseconds", "request_size_bytes",
+// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
+// help string. The names of the variable labels of the http_requests_total
+// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
+//
+// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
+// behavior of InstrumentHandler:
+//
+// prometheus.InstrumentHandlerWithOpts(
+// prometheus.SummaryOpts{
+// Subsystem: "http",
+// ConstLabels: prometheus.Labels{"handler": handlerName},
+// },
+// handler,
+// )
+//
+// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
+// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
+// and all its fields are set to the equally named fields in the provided
+// SummaryOpts.
+//
+// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
+// InstrumentHandler is. Use the tooling provided in package promhttp instead.
+func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
+ return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
+// the same issues) but provides more flexibility (at the cost of a more complex
+// call syntax). See InstrumentHandlerWithOpts for details how the provided
+// SummaryOpts are used.
+//
+// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
+// as InstrumentHandler is. Use the tooling provided in package promhttp instead.
+func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+ reqCnt := NewCounterVec(
+ CounterOpts{
+ Namespace: opts.Namespace,
+ Subsystem: opts.Subsystem,
+ Name: "requests_total",
+ Help: "Total number of HTTP requests made.",
+ ConstLabels: opts.ConstLabels,
+ },
+ instLabels,
+ )
+ if err := Register(reqCnt); err != nil {
+ if are, ok := err.(AlreadyRegisteredError); ok {
+ reqCnt = are.ExistingCollector.(*CounterVec)
+ } else {
+ panic(err)
+ }
+ }
+
+ opts.Name = "request_duration_microseconds"
+ opts.Help = "The HTTP request latencies in microseconds."
+ reqDur := NewSummary(opts)
+ if err := Register(reqDur); err != nil {
+ if are, ok := err.(AlreadyRegisteredError); ok {
+ reqDur = are.ExistingCollector.(Summary)
+ } else {
+ panic(err)
+ }
+ }
+
+ opts.Name = "request_size_bytes"
+ opts.Help = "The HTTP request sizes in bytes."
+ reqSz := NewSummary(opts)
+ if err := Register(reqSz); err != nil {
+ if are, ok := err.(AlreadyRegisteredError); ok {
+ reqSz = are.ExistingCollector.(Summary)
+ } else {
+ panic(err)
+ }
+ }
+
+ opts.Name = "response_size_bytes"
+ opts.Help = "The HTTP response sizes in bytes."
+ resSz := NewSummary(opts)
+ if err := Register(resSz); err != nil {
+ if are, ok := err.(AlreadyRegisteredError); ok {
+ resSz = are.ExistingCollector.(Summary)
+ } else {
+ panic(err)
+ }
+ }
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+
+ delegate := &responseWriterDelegator{ResponseWriter: w}
+ out := computeApproximateRequestSize(r)
+
+ _, cn := w.(http.CloseNotifier)
+ _, fl := w.(http.Flusher)
+ _, hj := w.(http.Hijacker)
+ _, rf := w.(io.ReaderFrom)
+ var rw http.ResponseWriter
+ if cn && fl && hj && rf {
+ rw = &fancyResponseWriterDelegator{delegate}
+ } else {
+ rw = delegate
+ }
+ handlerFunc(rw, r)
+
+ elapsed := float64(time.Since(now)) / float64(time.Microsecond)
+
+ method := sanitizeMethod(r.Method)
+ code := sanitizeCode(delegate.status)
+ reqCnt.WithLabelValues(method, code).Inc()
+ reqDur.Observe(elapsed)
+ resSz.Observe(float64(delegate.written))
+ reqSz.Observe(float64(<-out))
+ })
+}
+
+func computeApproximateRequestSize(r *http.Request) <-chan int {
+ // Get URL length in current goroutine for avoiding a race condition.
+ // HandlerFunc that runs in parallel may modify the URL.
+ s := 0
+ if r.URL != nil {
+ s += len(r.URL.String())
+ }
+
+ out := make(chan int, 1)
+
+ go func() {
+ 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)
+ }
+ out <- s
+ close(out)
+ }()
+
+ return out
+}
+
+type responseWriterDelegator struct {
+ http.ResponseWriter
+
+ status int
+ written int64
+ wroteHeader bool
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+ r.status = code
+ r.wroteHeader = true
+ r.ResponseWriter.WriteHeader(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 fancyResponseWriterDelegator struct {
+ *responseWriterDelegator
+}
+
+func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
+ return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+func (f *fancyResponseWriterDelegator) Flush() {
+ f.ResponseWriter.(http.Flusher).Flush()
+}
+
+func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+ return f.ResponseWriter.(http.Hijacker).Hijack()
+}
+
+func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
+ if !f.wroteHeader {
+ f.WriteHeader(http.StatusOK)
+ }
+ n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
+ f.written += n
+ return n, err
+}
+
+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)
+ }
+}
+
+func sanitizeCode(s int) string {
+ switch s {
+ case 100:
+ return "100"
+ case 101:
+ return "101"
+
+ case 200:
+ 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)
+ }
+}
+
+// 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,
+ )
+}