created docker-prometheus compose file and edited the Prometheus yml file

prom/util/httputil/client.go

@@ -0,0 +1,110 @@
+// Copyright 2013 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 httputil
+
+import (
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+// NewClient returns a http.Client using the specified http.RoundTripper.
+func NewClient(rt http.RoundTripper) *http.Client {
+	return &http.Client{Transport: rt}
+}
+
+// NewDeadlineClient returns a new http.Client which will time out long running
+// requests.
+func NewDeadlineClient(timeout time.Duration, proxyURL *url.URL) *http.Client {
+	return NewClient(NewDeadlineRoundTripper(timeout, proxyURL))
+}
+
+// NewDeadlineRoundTripper returns a new http.RoundTripper which will time out
+// long running requests.
+func NewDeadlineRoundTripper(timeout time.Duration, proxyURL *url.URL) http.RoundTripper {
+	return &http.Transport{
+		// Set proxy (if null, then becomes a direct connection)
+		Proxy: http.ProxyURL(proxyURL),
+		// We need to disable keepalive, because we set a deadline on the
+		// underlying connection.
+		DisableKeepAlives: true,
+		Dial: func(netw, addr string) (c net.Conn, err error) {
+			start := time.Now()
+
+			c, err = net.DialTimeout(netw, addr, timeout)
+
+			if err == nil {
+				c.SetDeadline(start.Add(timeout))
+			}
+
+			return
+		},
+	}
+}
+
+type bearerAuthRoundTripper struct {
+	bearerToken string
+	rt          http.RoundTripper
+}
+
+// NewBearerAuthRoundTripper adds the provided bearer token to a request unless the authorization
+// header has already been set.
+func NewBearerAuthRoundTripper(bearer string, rt http.RoundTripper) http.RoundTripper {
+	return &bearerAuthRoundTripper{bearer, rt}
+}
+
+func (rt *bearerAuthRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	if len(req.Header.Get("Authorization")) == 0 {
+		req = cloneRequest(req)
+		req.Header.Set("Authorization", "Bearer "+rt.bearerToken)
+	}
+
+	return rt.rt.RoundTrip(req)
+}
+
+type basicAuthRoundTripper struct {
+	username string
+	password string
+	rt       http.RoundTripper
+}
+
+// NewBasicAuthRoundTripper will apply a BASIC auth authorization header to a request unless it has
+// already been set.
+func NewBasicAuthRoundTripper(username, password string, rt http.RoundTripper) http.RoundTripper {
+	return &basicAuthRoundTripper{username, password, rt}
+}
+
+func (rt *basicAuthRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	if len(req.Header.Get("Authorization")) != 0 {
+		return rt.rt.RoundTrip(req)
+	}
+	req = cloneRequest(req)
+	req.SetBasicAuth(rt.username, rt.password)
+	return rt.rt.RoundTrip(req)
+}
+
+// cloneRequest returns a clone of the provided *http.Request.
+// The clone is a shallow copy of the struct and its Header map.
+func cloneRequest(r *http.Request) *http.Request {
+	// Shallow copy of the struct.
+	r2 := new(http.Request)
+	*r2 = *r
+	// Deep copy of the Header.
+	r2.Header = make(http.Header)
+	for k, s := range r.Header {
+		r2.Header[k] = s
+	}
+	return r2
+}

prom/util/httputil/compression.go

@@ -0,0 +1,92 @@
+// Copyright 2013 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 httputil
+
+import (
+	"compress/gzip"
+	"compress/zlib"
+	"io"
+	"net/http"
+	"strings"
+)
+
+const (
+	acceptEncodingHeader  = "Accept-Encoding"
+	contentEncodingHeader = "Content-Encoding"
+	gzipEncoding          = "gzip"
+	deflateEncoding       = "deflate"
+)
+
+// Wrapper around http.Handler which adds suitable response compression based
+// on the client's Accept-Encoding headers.
+type compressedResponseWriter struct {
+	http.ResponseWriter
+	writer io.Writer
+}
+
+// Writes HTTP response content data.
+func (c *compressedResponseWriter) Write(p []byte) (int, error) {
+	return c.writer.Write(p)
+}
+
+// Closes the compressedResponseWriter and ensures to flush all data before.
+func (c *compressedResponseWriter) Close() {
+	if zlibWriter, ok := c.writer.(*zlib.Writer); ok {
+		zlibWriter.Flush()
+	}
+	if gzipWriter, ok := c.writer.(*gzip.Writer); ok {
+		gzipWriter.Flush()
+	}
+	if closer, ok := c.writer.(io.Closer); ok {
+		defer closer.Close()
+	}
+}
+
+// Constructs a new compressedResponseWriter based on client request headers.
+func newCompressedResponseWriter(writer http.ResponseWriter, req *http.Request) *compressedResponseWriter {
+	encodings := strings.Split(req.Header.Get(acceptEncodingHeader), ",")
+	for _, encoding := range encodings {
+		switch strings.TrimSpace(encoding) {
+		case gzipEncoding:
+			writer.Header().Set(contentEncodingHeader, gzipEncoding)
+			return &compressedResponseWriter{
+				ResponseWriter: writer,
+				writer:         gzip.NewWriter(writer),
+			}
+		case deflateEncoding:
+			writer.Header().Set(contentEncodingHeader, deflateEncoding)
+			return &compressedResponseWriter{
+				ResponseWriter: writer,
+				writer:         zlib.NewWriter(writer),
+			}
+		}
+	}
+	return &compressedResponseWriter{
+		ResponseWriter: writer,
+		writer:         writer,
+	}
+}
+
+// CompressionHandler is a wrapper around http.Handler which adds suitable
+// response compression based on the client's Accept-Encoding headers.
+type CompressionHandler struct {
+	Handler http.Handler
+}
+
+// ServeHTTP adds compression to the original http.Handler's ServeHTTP() method.
+func (c CompressionHandler) ServeHTTP(writer http.ResponseWriter, req *http.Request) {
+	compWriter := newCompressedResponseWriter(writer, req)
+	c.Handler.ServeHTTP(compWriter, req)
+	compWriter.Close()
+}