@@ -143,7 +143,7 @@ github.com/coreos/pkg                               3ac0863d7acf3bc44daf49afef89

 code.cloudfoundry.org/clock                         02e53af36e6c978af692887ed449b74026d76fec

 # prometheus

-github.com/prometheus/client_golang                 c5b7fccd204277076155f10851dad72b76a49317 # v0.8.0

+github.com/prometheus/client_golang                 2641b987480bca71fb39738eb8c8b0d577cb1d76 # v0.9.4

 github.com/beorn7/perks                             37c8de3658fcb183f997c4e13e8337516ab753e6 # v1.0.1

 github.com/prometheus/client_model                  d1d2010b5beead3fa1c5f271a5cf626e40b3ad6e # v0.1.0

 github.com/prometheus/common                        287d3e634a1e550c9e463dd7e5a75a422c614505 # v0.7.0

@@ -159,7 +159,7 @@ github.com/inconshreveable/mousetrap                76626ae9c91c4f2a10f34cad8ce8

 github.com/morikuni/aec                             39771216ff4c63d11f5e604076f9c45e8be1067b

 # metrics

-github.com/docker/go-metrics                        d466d4f6fd960e01820085bd7e1a24426ee7ef18

+github.com/docker/go-metrics                        b619b3592b65de4f087d9f16863a7e6ff905973c # v0.0.1

 github.com/opencontainers/selinux                   3a1f366feb7aecbf7a0e71ac4cea88b31597de9e # v1.2.2

new file mode 100644

@@ -0,0 +1,191 @@

+

+                                 Apache License

+                           Version 2.0, January 2004

+                        https://www.apache.org/licenses/

+

+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

+

+   1. Definitions.

+

+      "License" shall mean the terms and conditions for use, reproduction,

+      and distribution as defined by Sections 1 through 9 of this document.

+

+      "Licensor" shall mean the copyright owner or entity authorized by

+      the copyright owner that is granting the License.

+

+      "Legal Entity" shall mean the union of the acting entity and all

+      other entities that control, are controlled by, or are under common

+      control with that entity. For the purposes of this definition,

+      "control" means (i) the power, direct or indirect, to cause the

+      direction or management of such entity, whether by contract or

+      otherwise, or (ii) ownership of fifty percent (50%) or more of the

+      outstanding shares, or (iii) beneficial ownership of such entity.

+

+      "You" (or "Your") shall mean an individual or Legal Entity

+      exercising permissions granted by this License.

+

+      "Source" form shall mean the preferred form for making modifications,

+      including but not limited to software source code, documentation

+      source, and configuration files.

+

+      "Object" form shall mean any form resulting from mechanical

+      transformation or translation of a Source form, including but

+      not limited to compiled object code, generated documentation,

+      and conversions to other media types.

+

+      "Work" shall mean the work of authorship, whether in Source or

+      Object form, made available under the License, as indicated by a

+      copyright notice that is included in or attached to the work

+      (an example is provided in the Appendix below).

+

+      "Derivative Works" shall mean any work, whether in Source or Object

+      form, that is based on (or derived from) the Work and for which the

+      editorial revisions, annotations, elaborations, or other modifications

+      represent, as a whole, an original work of authorship. For the purposes

+      of this License, Derivative Works shall not include works that remain

+      separable from, or merely link (or bind by name) to the interfaces of,

+      the Work and Derivative Works thereof.

+

+      "Contribution" shall mean any work of authorship, including

+      the original version of the Work and any modifications or additions

+      to that Work or Derivative Works thereof, that is intentionally

+      submitted to Licensor for inclusion in the Work by the copyright owner

+      or by an individual or Legal Entity authorized to submit on behalf of

+      the copyright owner. For the purposes of this definition, "submitted"

+      means any form of electronic, verbal, or written communication sent

+      to the Licensor or its representatives, including but not limited to

+      communication on electronic mailing lists, source code control systems,

+      and issue tracking systems that are managed by, or on behalf of, the

+      Licensor for the purpose of discussing and improving the Work, but

+      excluding communication that is conspicuously marked or otherwise

+      designated in writing by the copyright owner as "Not a Contribution."

+

+      "Contributor" shall mean Licensor and any individual or Legal Entity

+      on behalf of whom a Contribution has been received by Licensor and

+      subsequently incorporated within the Work.

+

+   2. Grant of Copyright License. Subject to the terms and conditions of

+      this License, each Contributor hereby grants to You a perpetual,

+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable

+      copyright license to reproduce, prepare Derivative Works of,

+      publicly display, publicly perform, sublicense, and distribute the

+      Work and such Derivative Works in Source or Object form.

+

+   3. Grant of Patent License. Subject to the terms and conditions of

+      this License, each Contributor hereby grants to You a perpetual,

+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable

+      (except as stated in this section) patent license to make, have made,

+      use, offer to sell, sell, import, and otherwise transfer the Work,

+      where such license applies only to those patent claims licensable

+      by such Contributor that are necessarily infringed by their

+      Contribution(s) alone or by combination of their Contribution(s)

+      with the Work to which such Contribution(s) was submitted. If You

+      institute patent litigation against any entity (including a

+      cross-claim or counterclaim in a lawsuit) alleging that the Work

+      or a Contribution incorporated within the Work constitutes direct

+      or contributory patent infringement, then any patent licenses

+      granted to You under this License for that Work shall terminate

+      as of the date such litigation is filed.

+

+   4. Redistribution. You may reproduce and distribute copies of the

+      Work or Derivative Works thereof in any medium, with or without

+      modifications, and in Source or Object form, provided that You

+      meet the following conditions:

+

+      (a) You must give any other recipients of the Work or

+          Derivative Works a copy of this License; and

+

+      (b) You must cause any modified files to carry prominent notices

+          stating that You changed the files; and

+

+      (c) You must retain, in the Source form of any Derivative Works

+          that You distribute, all copyright, patent, trademark, and

+          attribution notices from the Source form of the Work,

+          excluding those notices that do not pertain to any part of

+          the Derivative Works; and

+

+      (d) If the Work includes a "NOTICE" text file as part of its

+          distribution, then any Derivative Works that You distribute must

+          include a readable copy of the attribution notices contained

+          within such NOTICE file, excluding those notices that do not

+          pertain to any part of the Derivative Works, in at least one

+          of the following places: within a NOTICE text file distributed

+          as part of the Derivative Works; within the Source form or

+          documentation, if provided along with the Derivative Works; or,

+          within a display generated by the Derivative Works, if and

+          wherever such third-party notices normally appear. The contents

+          of the NOTICE file are for informational purposes only and

+          do not modify the License. You may add Your own attribution

+          notices within Derivative Works that You distribute, alongside

+          or as an addendum to the NOTICE text from the Work, provided

+          that such additional attribution notices cannot be construed

+          as modifying the License.

+

+      You may add Your own copyright statement to Your modifications and

+      may provide additional or different license terms and conditions

+      for use, reproduction, or distribution of Your modifications, or

+      for any such Derivative Works as a whole, provided Your use,

+      reproduction, and distribution of the Work otherwise complies with

+      the conditions stated in this License.

+

+   5. Submission of Contributions. Unless You explicitly state otherwise,

+      any Contribution intentionally submitted for inclusion in the Work

+      by You to the Licensor shall be under the terms and conditions of

+      this License, without any additional terms or conditions.

+      Notwithstanding the above, nothing herein shall supersede or modify

+      the terms of any separate license agreement you may have executed

+      with Licensor regarding such Contributions.

+

+   6. Trademarks. This License does not grant permission to use the trade

+      names, trademarks, service marks, or product names of the Licensor,

+      except as required for reasonable and customary use in describing the

+      origin of the Work and reproducing the content of the NOTICE file.

+

+   7. Disclaimer of Warranty. Unless required by applicable law or

+      agreed to in writing, Licensor provides the Work (and each

+      Contributor provides its Contributions) on an "AS IS" BASIS,

+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or

+      implied, including, without limitation, any warranties or conditions

+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A

+      PARTICULAR PURPOSE. You are solely responsible for determining the

+      appropriateness of using or redistributing the Work and assume any

+      risks associated with Your exercise of permissions under this License.

+

+   8. Limitation of Liability. In no event and under no legal theory,

+      whether in tort (including negligence), contract, or otherwise,

+      unless required by applicable law (such as deliberate and grossly

+      negligent acts) or agreed to in writing, shall any Contributor be

+      liable to You for damages, including any direct, indirect, special,

+      incidental, or consequential damages of any character arising as a

+      result of this License or out of the use or inability to use the

+      Work (including but not limited to damages for loss of goodwill,

+      work stoppage, computer failure or malfunction, or any and all

+      other commercial damages or losses), even if such Contributor

+      has been advised of the possibility of such damages.

+

+   9. Accepting Warranty or Additional Liability. While redistributing

+      the Work or Derivative Works thereof, You may choose to offer,

+      and charge a fee for, acceptance of support, warranty, indemnity,

+      or other liability obligations and/or rights consistent with this

+      License. However, in accepting such obligations, You may act only

+      on Your own behalf and on Your sole responsibility, not on behalf

+      of any other Contributor, and only if You agree to indemnify,

+      defend, and hold each Contributor harmless for any liability

+      incurred by, or claims asserted against, such Contributor by reason

+      of your accepting any such warranty or additional liability.

+

+   END OF TERMS AND CONDITIONS

+

+   Copyright 2013-2016 Docker, Inc.

+

+   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

+

+       https://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.

deleted file mode 100644

@@ -1,191 +0,0 @@

-

-                                 Apache License

-                           Version 2.0, January 2004

-                        https://www.apache.org/licenses/

-

-   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

-

-   1. Definitions.

-

-      "License" shall mean the terms and conditions for use, reproduction,

-      and distribution as defined by Sections 1 through 9 of this document.

-

-      "Licensor" shall mean the copyright owner or entity authorized by

-      the copyright owner that is granting the License.

-

-      "Legal Entity" shall mean the union of the acting entity and all

-      other entities that control, are controlled by, or are under common

-      control with that entity. For the purposes of this definition,

-      "control" means (i) the power, direct or indirect, to cause the

-      direction or management of such entity, whether by contract or

-      otherwise, or (ii) ownership of fifty percent (50%) or more of the

-      outstanding shares, or (iii) beneficial ownership of such entity.

-

-      "You" (or "Your") shall mean an individual or Legal Entity

-      exercising permissions granted by this License.

-

-      "Source" form shall mean the preferred form for making modifications,

-      including but not limited to software source code, documentation

-      source, and configuration files.

-

-      "Object" form shall mean any form resulting from mechanical

-      transformation or translation of a Source form, including but

-      not limited to compiled object code, generated documentation,

-      and conversions to other media types.

-

-      "Work" shall mean the work of authorship, whether in Source or

-      Object form, made available under the License, as indicated by a

-      copyright notice that is included in or attached to the work

-      (an example is provided in the Appendix below).

-

-      "Derivative Works" shall mean any work, whether in Source or Object

-      form, that is based on (or derived from) the Work and for which the

-      editorial revisions, annotations, elaborations, or other modifications

-      represent, as a whole, an original work of authorship. For the purposes

-      of this License, Derivative Works shall not include works that remain

-      separable from, or merely link (or bind by name) to the interfaces of,

-      the Work and Derivative Works thereof.

-

-      "Contribution" shall mean any work of authorship, including

-      the original version of the Work and any modifications or additions

-      to that Work or Derivative Works thereof, that is intentionally

-      submitted to Licensor for inclusion in the Work by the copyright owner

-      or by an individual or Legal Entity authorized to submit on behalf of

-      the copyright owner. For the purposes of this definition, "submitted"

-      means any form of electronic, verbal, or written communication sent

-      to the Licensor or its representatives, including but not limited to

-      communication on electronic mailing lists, source code control systems,

-      and issue tracking systems that are managed by, or on behalf of, the

-      Licensor for the purpose of discussing and improving the Work, but

-      excluding communication that is conspicuously marked or otherwise

-      designated in writing by the copyright owner as "Not a Contribution."

-

-      "Contributor" shall mean Licensor and any individual or Legal Entity

-      on behalf of whom a Contribution has been received by Licensor and

-      subsequently incorporated within the Work.

-

-   2. Grant of Copyright License. Subject to the terms and conditions of

-      this License, each Contributor hereby grants to You a perpetual,

-      worldwide, non-exclusive, no-charge, royalty-free, irrevocable

-      copyright license to reproduce, prepare Derivative Works of,

-      publicly display, publicly perform, sublicense, and distribute the

-      Work and such Derivative Works in Source or Object form.

-

-   3. Grant of Patent License. Subject to the terms and conditions of

-      this License, each Contributor hereby grants to You a perpetual,

-      worldwide, non-exclusive, no-charge, royalty-free, irrevocable

-      (except as stated in this section) patent license to make, have made,

-      use, offer to sell, sell, import, and otherwise transfer the Work,

-      where such license applies only to those patent claims licensable

-      by such Contributor that are necessarily infringed by their

-      Contribution(s) alone or by combination of their Contribution(s)

-      with the Work to which such Contribution(s) was submitted. If You

-      institute patent litigation against any entity (including a

-      cross-claim or counterclaim in a lawsuit) alleging that the Work

-      or a Contribution incorporated within the Work constitutes direct

-      or contributory patent infringement, then any patent licenses

-      granted to You under this License for that Work shall terminate

-      as of the date such litigation is filed.

-

-   4. Redistribution. You may reproduce and distribute copies of the

-      Work or Derivative Works thereof in any medium, with or without

-      modifications, and in Source or Object form, provided that You

-      meet the following conditions:

-

-      (a) You must give any other recipients of the Work or

-          Derivative Works a copy of this License; and

-

-      (b) You must cause any modified files to carry prominent notices

-          stating that You changed the files; and

-

-      (c) You must retain, in the Source form of any Derivative Works

-          that You distribute, all copyright, patent, trademark, and

-          attribution notices from the Source form of the Work,

-          excluding those notices that do not pertain to any part of

-          the Derivative Works; and

-

-      (d) If the Work includes a "NOTICE" text file as part of its

-          distribution, then any Derivative Works that You distribute must

-          include a readable copy of the attribution notices contained

-          within such NOTICE file, excluding those notices that do not

-          pertain to any part of the Derivative Works, in at least one

-          of the following places: within a NOTICE text file distributed

-          as part of the Derivative Works; within the Source form or

-          documentation, if provided along with the Derivative Works; or,

-          within a display generated by the Derivative Works, if and

-          wherever such third-party notices normally appear. The contents

-          of the NOTICE file are for informational purposes only and

-          do not modify the License. You may add Your own attribution

-          notices within Derivative Works that You distribute, alongside

-          or as an addendum to the NOTICE text from the Work, provided

-          that such additional attribution notices cannot be construed

-          as modifying the License.

-

-      You may add Your own copyright statement to Your modifications and

-      may provide additional or different license terms and conditions

-      for use, reproduction, or distribution of Your modifications, or

-      for any such Derivative Works as a whole, provided Your use,

-      reproduction, and distribution of the Work otherwise complies with

-      the conditions stated in this License.

-

-   5. Submission of Contributions. Unless You explicitly state otherwise,

-      any Contribution intentionally submitted for inclusion in the Work

-      by You to the Licensor shall be under the terms and conditions of

-      this License, without any additional terms or conditions.

-      Notwithstanding the above, nothing herein shall supersede or modify

-      the terms of any separate license agreement you may have executed

-      with Licensor regarding such Contributions.

-

-   6. Trademarks. This License does not grant permission to use the trade

-      names, trademarks, service marks, or product names of the Licensor,

-      except as required for reasonable and customary use in describing the

-      origin of the Work and reproducing the content of the NOTICE file.

-

-   7. Disclaimer of Warranty. Unless required by applicable law or

-      agreed to in writing, Licensor provides the Work (and each

-      Contributor provides its Contributions) on an "AS IS" BASIS,

-      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or

-      implied, including, without limitation, any warranties or conditions

-      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A

-      PARTICULAR PURPOSE. You are solely responsible for determining the

-      appropriateness of using or redistributing the Work and assume any

-      risks associated with Your exercise of permissions under this License.

-

-   8. Limitation of Liability. In no event and under no legal theory,

-      whether in tort (including negligence), contract, or otherwise,

-      unless required by applicable law (such as deliberate and grossly

-      negligent acts) or agreed to in writing, shall any Contributor be

-      liable to You for damages, including any direct, indirect, special,

-      incidental, or consequential damages of any character arising as a

-      result of this License or out of the use or inability to use the

-      Work (including but not limited to damages for loss of goodwill,

-      work stoppage, computer failure or malfunction, or any and all

-      other commercial damages or losses), even if such Contributor

-      has been advised of the possibility of such damages.

-

-   9. Accepting Warranty or Additional Liability. While redistributing

-      the Work or Derivative Works thereof, You may choose to offer,

-      and charge a fee for, acceptance of support, warranty, indemnity,

-      or other liability obligations and/or rights consistent with this

-      License. However, in accepting such obligations, You may act only

-      on Your own behalf and on Your sole responsibility, not on behalf

-      of any other Contributor, and only if You agree to indemnify,

-      defend, and hold each Contributor harmless for any liability

-      incurred by, or claims asserted against, such Contributor by reason

-      of your accepting any such warranty or additional liability.

-

-   END OF TERMS AND CONDITIONS

-

-   Copyright 2013-2016 Docker, Inc.

-

-   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

-

-       https://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.

@@ -68,9 +68,21 @@ If you need to use a unit but it is not defined in the package please open a PR

 Package documentation can be found [here](https://godoc.org/github.com/docker/go-metrics).

+## HTTP Metrics

+

+To instrument a http handler, you can wrap the code like this:

+

+```go

+namespace := metrics.NewNamespace("docker_distribution", "http", metrics.Labels{"handler": "your_http_handler_name"})

+httpMetrics := namespace.NewDefaultHttpMetrics()

+metrics.Register(namespace)

+instrumentedHandler = metrics.InstrumentHandler(httpMetrics, unInstrumentedHandler)

+```

+Note: The `handler` label must be provided when a new namespace is created.

+

 ## Additional Metrics

-Additional metrics are also defined here that are not avaliable in the prometheus client.

+Additional metrics are also defined here that are not available in the prometheus client.

 If you need a custom metrics and it is generic enough to be used by multiple projects, define it here.

new file mode 100644

@@ -0,0 +1,5 @@

+module github.com/docker/go-metrics

+

+go 1.11

+

+require github.com/prometheus/client_golang v1.1.0

@@ -4,10 +4,71 @@ import (

 	"net/http"

 	"github.com/prometheus/client_golang/prometheus"

+	"github.com/prometheus/client_golang/prometheus/promhttp"

+)

+

+// HTTPHandlerOpts describes a set of configurable options of http metrics

+type HTTPHandlerOpts struct {

+	DurationBuckets     []float64

+	RequestSizeBuckets  []float64

+	ResponseSizeBuckets []float64

+}

+

+const (

+	InstrumentHandlerResponseSize = iota

+	InstrumentHandlerRequestSize

+	InstrumentHandlerDuration

+	InstrumentHandlerCounter

+	InstrumentHandlerInFlight

+)

+

+type HTTPMetric struct {

+	prometheus.Collector

+	handlerType int

+}

+

+var (

+	defaultDurationBuckets     = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10, 25, 60}

+	defaultRequestSizeBuckets  = prometheus.ExponentialBuckets(1024, 2, 22) //1K to 4G

+	defaultResponseSizeBuckets = defaultRequestSizeBuckets

 )

 // Handler returns the global http.Handler that provides the prometheus

-// metrics format on GET requests

+// metrics format on GET requests. This handler is no longer instrumented.

 func Handler() http.Handler {

-	return prometheus.Handler()

+	return promhttp.Handler()

+}

+

+func InstrumentHandler(metrics []*HTTPMetric, handler http.Handler) http.HandlerFunc {

+	return InstrumentHandlerFunc(metrics, handler.ServeHTTP)

+}

+

+func InstrumentHandlerFunc(metrics []*HTTPMetric, handlerFunc http.HandlerFunc) http.HandlerFunc {

+	var handler http.Handler

+	handler = http.HandlerFunc(handlerFunc)

+	for _, metric := range metrics {

+		switch metric.handlerType {

+		case InstrumentHandlerResponseSize:

+			if collector, ok := metric.Collector.(prometheus.ObserverVec); ok {

+				handler = promhttp.InstrumentHandlerResponseSize(collector, handler)

+			}

+		case InstrumentHandlerRequestSize:

+			if collector, ok := metric.Collector.(prometheus.ObserverVec); ok {

+				handler = promhttp.InstrumentHandlerRequestSize(collector, handler)

+			}

+		case InstrumentHandlerDuration:

+			if collector, ok := metric.Collector.(prometheus.ObserverVec); ok {

+				handler = promhttp.InstrumentHandlerDuration(collector, handler)

+			}

+		case InstrumentHandlerCounter:

+			if collector, ok := metric.Collector.(*prometheus.CounterVec); ok {

+				handler = promhttp.InstrumentHandlerCounter(collector, handler)

+			}

+		case InstrumentHandlerInFlight:

+			if collector, ok := metric.Collector.(prometheus.Gauge); ok {

+				handler = promhttp.InstrumentHandlerInFlight(collector, handler)

+			}

+		}

+	}

+	return handler.ServeHTTP

 }

@@ -179,3 +179,137 @@ func makeName(name string, unit Unit) string {

 	return fmt.Sprintf("%s_%s", name, unit)

 }

+

+func (n *Namespace) NewDefaultHttpMetrics(handlerName string) []*HTTPMetric {

+	return n.NewHttpMetricsWithOpts(handlerName, HTTPHandlerOpts{

+		DurationBuckets:     defaultDurationBuckets,

+		RequestSizeBuckets:  defaultResponseSizeBuckets,

+		ResponseSizeBuckets: defaultResponseSizeBuckets,

+	})

+}

+

+func (n *Namespace) NewHttpMetrics(handlerName string, durationBuckets, requestSizeBuckets, responseSizeBuckets []float64) []*HTTPMetric {

+	return n.NewHttpMetricsWithOpts(handlerName, HTTPHandlerOpts{

+		DurationBuckets:     durationBuckets,

+		RequestSizeBuckets:  requestSizeBuckets,

+		ResponseSizeBuckets: responseSizeBuckets,

+	})

+}

+

+func (n *Namespace) NewHttpMetricsWithOpts(handlerName string, opts HTTPHandlerOpts) []*HTTPMetric {

+	var httpMetrics []*HTTPMetric

+	inFlightMetric := n.NewInFlightGaugeMetric(handlerName)

+	requestTotalMetric := n.NewRequestTotalMetric(handlerName)

+	requestDurationMetric := n.NewRequestDurationMetric(handlerName, opts.DurationBuckets)

+	requestSizeMetric := n.NewRequestSizeMetric(handlerName, opts.RequestSizeBuckets)

+	responseSizeMetric := n.NewResponseSizeMetric(handlerName, opts.ResponseSizeBuckets)

+	httpMetrics = append(httpMetrics, inFlightMetric, requestDurationMetric, requestTotalMetric, requestSizeMetric, responseSizeMetric)

+	return httpMetrics

+}

+

+func (n *Namespace) NewInFlightGaugeMetric(handlerName string) *HTTPMetric {

+	labels := prometheus.Labels(n.labels)

+	labels["handler"] = handlerName

+	metric := prometheus.NewGauge(prometheus.GaugeOpts{

+		Namespace:   n.name,

+		Subsystem:   n.subsystem,

+		Name:        "in_flight_requests",

+		Help:        "The in-flight HTTP requests",

+		ConstLabels: prometheus.Labels(labels),

+	})

+	httpMetric := &HTTPMetric{

+		Collector:   metric,

+		handlerType: InstrumentHandlerInFlight,

+	}

+	n.Add(httpMetric)

+	return httpMetric

+}

+

+func (n *Namespace) NewRequestTotalMetric(handlerName string) *HTTPMetric {

+	labels := prometheus.Labels(n.labels)

+	labels["handler"] = handlerName

+	metric := prometheus.NewCounterVec(

+		prometheus.CounterOpts{

+			Namespace:   n.name,

+			Subsystem:   n.subsystem,

+			Name:        "requests_total",

+			Help:        "Total number of HTTP requests made.",

+			ConstLabels: prometheus.Labels(labels),

+		},

+		[]string{"code", "method"},

+	)

+	httpMetric := &HTTPMetric{

+		Collector:   metric,

+		handlerType: InstrumentHandlerCounter,

+	}

+	n.Add(httpMetric)

+	return httpMetric

+}

+func (n *Namespace) NewRequestDurationMetric(handlerName string, buckets []float64) *HTTPMetric {

+	if len(buckets) == 0 {

+		panic("DurationBuckets must be provided")

+	}

+	labels := prometheus.Labels(n.labels)

+	labels["handler"] = handlerName

+	opts := prometheus.HistogramOpts{

+		Namespace:   n.name,

+		Subsystem:   n.subsystem,

+		Name:        "request_duration_seconds",

+		Help:        "The HTTP request latencies in seconds.",

+		Buckets:     buckets,

+		ConstLabels: prometheus.Labels(labels),

+	}

+	metric := prometheus.NewHistogramVec(opts, []string{"method"})

+	httpMetric := &HTTPMetric{

+		Collector:   metric,

+		handlerType: InstrumentHandlerDuration,

+	}

+	n.Add(httpMetric)

+	return httpMetric

+}

+

+func (n *Namespace) NewRequestSizeMetric(handlerName string, buckets []float64) *HTTPMetric {

+	if len(buckets) == 0 {

+		panic("RequestSizeBuckets must be provided")

+	}

+	labels := prometheus.Labels(n.labels)

+	labels["handler"] = handlerName

+	opts := prometheus.HistogramOpts{

+		Namespace:   n.name,

+		Subsystem:   n.subsystem,

+		Name:        "request_size_bytes",

+		Help:        "The HTTP request sizes in bytes.",

+		Buckets:     buckets,

+		ConstLabels: prometheus.Labels(labels),

+	}

+	metric := prometheus.NewHistogramVec(opts, []string{})

+	httpMetric := &HTTPMetric{

+		Collector:   metric,

+		handlerType: InstrumentHandlerRequestSize,

+	}

+	n.Add(httpMetric)

+	return httpMetric

+}

+

+func (n *Namespace) NewResponseSizeMetric(handlerName string, buckets []float64) *HTTPMetric {

+	if len(buckets) == 0 {

+		panic("ResponseSizeBuckets must be provided")

+	}

+	labels := prometheus.Labels(n.labels)

+	labels["handler"] = handlerName

+	opts := prometheus.HistogramOpts{

+		Namespace:   n.name,

+		Subsystem:   n.subsystem,

+		Name:        "response_size_bytes",

+		Help:        "The HTTP response sizes in bytes.",

+		Buckets:     buckets,

+		ConstLabels: prometheus.Labels(labels),

+	}

+	metrics := prometheus.NewHistogramVec(opts, []string{})

+	httpMetric := &HTTPMetric{

+		Collector:   metrics,

+		handlerType: InstrumentHandlerResponseSize,

+	}

+	n.Add(httpMetric)

+	return httpMetric

+}

@@ -28,15 +28,27 @@ type Timer interface {

 // LabeledTimer is a timer that must have label values populated before use.

 type LabeledTimer interface {

-	WithValues(labels ...string) Timer

+	WithValues(labels ...string) *labeledTimerObserver

 }

 type labeledTimer struct {

 	m *prometheus.HistogramVec

 }

-func (lt *labeledTimer) WithValues(labels ...string) Timer {

-	return &timer{m: lt.m.WithLabelValues(labels...)}

+type labeledTimerObserver struct {

+	m prometheus.Observer

+}

+

+func (lbo *labeledTimerObserver) Update(duration time.Duration) {

+	lbo.m.Observe(duration.Seconds())

+}

+

+func (lbo *labeledTimerObserver) UpdateSince(since time.Time) {

+	lbo.m.Observe(time.Since(since).Seconds())

+}

+

+func (lt *labeledTimer) WithValues(labels ...string) *labeledTimerObserver {

+	return &labeledTimerObserver{m: lt.m.WithLabelValues(labels...)}

 }

 func (lt *labeledTimer) Describe(c chan<- *prometheus.Desc) {

@@ -48,7 +60,7 @@ func (lt *labeledTimer) Collect(c chan<- prometheus.Metric) {

 }

 type timer struct {

-	m prometheus.Histogram

+	m prometheus.Observer

 }

 func (t *timer) Update(duration time.Duration) {

@@ -60,9 +72,14 @@ func (t *timer) UpdateSince(since time.Time) {

 }

 func (t *timer) Describe(c chan<- *prometheus.Desc) {

-	t.m.Describe(c)

+	c <- t.m.(prometheus.Metric).Desc()

 }

 func (t *timer) Collect(c chan<- prometheus.Metric) {

-	t.m.Collect(c)

+	// Are there any observers that don't implement Collector? It is really

+	// unclear what the point of the upstream change was, but we'll let this

+	// panic if we get an observer that doesn't implement collector. In this

+	// case, we should almost always see metricVec objects, so this should

+	// never panic.

+	t.m.(prometheus.Collector).Collect(c)

 }

@@ -1,12 +1,52 @@

 # Prometheus Go client library

 [![Build Status](https://travis-ci.org/prometheus/client_golang.svg?branch=master)](https://travis-ci.org/prometheus/client_golang)

+[![Go Report Card](https://goreportcard.com/badge/github.com/prometheus/client_golang)](https://goreportcard.com/report/github.com/prometheus/client_golang)

+[![go-doc](https://godoc.org/github.com/prometheus/client_golang?status.svg)](https://godoc.org/github.com/prometheus/client_golang)

 This is the [Go](http://golang.org) client library for

 [Prometheus](http://prometheus.io). It has two separate parts, one for

 instrumenting application code, and one for creating clients that talk to the

 Prometheus HTTP API.

+__This library requires Go1.9 or later.__

+

+## Important note about releases, versioning, tagging, and stability

+

+In this repository, we used to mostly ignore the many coming and going

+dependency management tools for Go and instead wait for a tool that most of the

+community would converge on. Our bet is that this tool has arrived now in the

+form of [Go

+Modules](https://github.com/golang/go/wiki/Modules#how-to-upgrade-and-downgrade-dependencies).

+

+To make full use of what Go Modules are offering, the previous versioning

+roadmap for this repository had to be changed. In particular, Go Modules

+finally provide a way for incompatible versions of the same package to coexist

+in the same binary. For that, however, the versions must be tagged with

+different major versions of 1 or greater (following [Semantic

+Versioning](https://semver.org/)). Thus, we decided to abandon the original

+plan of introducing a lot of breaking changes _before_ releasing v1 of this

+repository, mostly driven by the widespread use this repository already has and

+the relatively stable state it is in.

+

+To leverage the mechanism Go Modules offers for a transition between major

+version, the current plan is the following:

+

+- The v0.9.x series of releases will see a small number of bugfix releases to

+  deal with a few remaining minor issues (#543, #542, #539).

+- After that, all features currently marked as _deprecated_ will be removed,

+  and the result will be released as v1.0.0.

+- The planned breaking changes previously gathered as part of the v0.10

+  milestone will now go into the v2 milestone. The v2 development happens in a

+  [separate branch](https://github.com/prometheus/client_golang/tree/dev-v2)

+  for the time being. v2 releases off that branch will happen once sufficient

+  stability is reached. v1 and v2 will coexist for a while to enable a

+  convenient transition.

+- The API client in prometheus/client_golang/api/… is still considered

+  experimental. While it will be tagged alongside the rest of the code

+  according to the plan above, we cannot strictly guarantee semver semantics

+  for it.

+

 ## Instrumenting applications

 [![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/prometheus)](http://gocover.io/github.com/prometheus/client_golang/prometheus) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus)

@@ -14,8 +54,8 @@ Prometheus HTTP API.

 The

 [`prometheus` directory](https://github.com/prometheus/client_golang/tree/master/prometheus)

 contains the instrumentation library. See the

-[best practices section](http://prometheus.io/docs/practices/naming/) of the

-Prometheus documentation to learn more about instrumenting applications.

+[guide](https://prometheus.io/docs/guides/go-application/) on the Prometheus

+website to learn more about instrumenting applications.

 The

 [`examples` directory](https://github.com/prometheus/client_golang/tree/master/examples)

@@ -23,13 +63,14 @@ contains simple examples of instrumented code.

 ## Client for the Prometheus HTTP API

-[![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/api/prometheus)](http://gocover.io/github.com/prometheus/client_golang/api/prometheus) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/api/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/api/prometheus)

+[![code-coverage](http://gocover.io/_badge/github.com/prometheus/client_golang/api/prometheus/v1)](http://gocover.io/github.com/prometheus/client_golang/api/prometheus/v1) [![go-doc](https://godoc.org/github.com/prometheus/client_golang/api/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/api)

 The

 [`api/prometheus` directory](https://github.com/prometheus/client_golang/tree/master/api/prometheus)

 contains the client for the

 [Prometheus HTTP API](http://prometheus.io/docs/querying/api/). It allows you

-to write Go applications that query time series data from a Prometheus server.

+to write Go applications that query time series data from a Prometheus

+server. It is still in alpha stage.

 ## Where is `model`, `extraction`, and `text`?

new file mode 100644

@@ -0,0 +1,13 @@

+module github.com/prometheus/client_golang

+

+require (

+	github.com/beorn7/perks v1.0.0

+	github.com/golang/protobuf v1.3.1

+	github.com/json-iterator/go v1.1.6

+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect

+	github.com/modern-go/reflect2 v1.0.1 // indirect

+	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90

+	github.com/prometheus/common v0.4.1

+	github.com/prometheus/procfs v0.0.2

+	github.com/stretchr/testify v1.3.0 // indirect

+)

new file mode 100644

@@ -0,0 +1,29 @@

+// Copyright 2019 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 go1.12

+

+package prometheus

+

+import "runtime/debug"

+

+// readBuildInfo is a wrapper around debug.ReadBuildInfo for Go 1.12+.

+func readBuildInfo() (path, version, sum string) {

+	path, version, sum = "unknown", "unknown", "unknown"

+	if bi, ok := debug.ReadBuildInfo(); ok {

+		path = bi.Main.Path

+		version = bi.Main.Version

+		sum = bi.Main.Sum

+	}

+	return

+}

new file mode 100644

@@ -0,0 +1,22 @@

+// Copyright 2019 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 !go1.12

+

+package prometheus

+

+// readBuildInfo is a wrapper around debug.ReadBuildInfo for Go versions before

+// 1.12. Remove this whole file once the minimum supported Go version is 1.12.

+func readBuildInfo() (path, version, sum string) {

+	return "unknown", "unknown", "unknown"

+}