Update go dependencies

vendor/github.com/prometheus/client_golang/CHANGELOG.md

@@ -1,3 +1,67 @@
+## 0.9.1 / 2018-11-03
+* [FEATURE] Add `WriteToTextfile` function to facilitate the creation of
+  *.prom files for the textfile collector of the node exporter. #489
+* [ENHANCEMENT] More descriptive error messages for inconsistent label
+  cardinality. #487
+* [ENHANCEMENT] Exposition: Use a GZIP encoder pool to avoid allocations in
+  high-frequency scrape scenarios. #366
+* [ENHANCEMENT] Exposition: Streaming serving of metrics data while encoding.
+  #482
+* [ENHANCEMENT] API client: Add a way to return the body of a 5xx response.
+  #479
+
+## 0.9.0 / 2018-10-15
+* [CHANGE] Go1.6 is no longer supported.
+* [CHANGE] More refinements of the `Registry` consistency checks: Duplicated
+  labels are now detected, but inconsistent label dimensions are now allowed.
+  Collisions with the “magic” metric and label names in Summaries and
+  Histograms are detected now. #108 #417 #471
+* [CHANGE] Changed `ProcessCollector` constructor. #219
+* [CHANGE] Changed Go counter `go_memstats_heap_released_bytes_total` to gauge
+  `go_memstats_heap_released_bytes`. #229
+* [CHANGE] Unexported `LabelPairSorter`. #453
+* [CHANGE] Removed the `Untyped` metric from direct instrumentation. #340
+* [CHANGE] Unexported `MetricVec`. #319
+* [CHANGE] Removed deprecated `Set` method from `Counter` #247
+* [CHANGE] Removed deprecated `RegisterOrGet` and `MustRegisterOrGet`. #247
+* [CHANGE] API client: Introduced versioned packages.
+* [FEATURE] A `Registerer` can be wrapped with prefixes and labels. #357
+* [FEATURE] “Describe by collect” helper function. #239
+* [FEATURE] Added package `testutil`. #58
+* [FEATURE] Timestamp can be explicitly set for const metrics. #187
+* [FEATURE] “Unchecked” collectors are possible now without cheating. #47
+* [FEATURE] Pushing to the Pushgateway reworked in package `push` to support
+  many new features. (The old functions are still usable but deprecated.) #372
+  #341
+* [FEATURE] Configurable connection limit for scrapes. #179
+* [FEATURE] New HTTP middlewares to instrument `http.Handler` and
+  `http.RoundTripper`. The old middlewares and the pre-instrumented `/metrics`
+  handler are (strongly) deprecated. #316 #57 #101 #224
+* [FEATURE] “Currying” for metric vectors. #320
+* [FEATURE] A `Summary` can be created without quantiles. #118
+* [FEATURE] Added a `Timer` helper type. #231
+* [FEATURE] Added a Graphite bridge. #197
+* [FEATURE] Help strings are now optional. #460
+* [FEATURE] Added `process_virtual_memory_max_bytes` metric. #438 #440
+* [FEATURE] Added `go_gc_cpu_fraction` and `go_threads` metrics. #281 #277
+* [FEATURE] Added `promauto` package with auto-registering metrics. #385 #393
+* [FEATURE] Add `SetToCurrentTime` method to `Gauge`. #259
+* [FEATURE] API client: Add AlertManager, Status, and Target methods. #402
+* [FEATURE] API client: Add admin methods. #398
+* [FEATURE] API client: Support series API. #361
+* [FEATURE] API client: Support querying label values.
+* [ENHANCEMENT] Smarter creation of goroutines during scraping. Solves memory
+  usage spikes in certain situations. #369
+* [ENHANCEMENT] Counters are now faster if dealing with integers only. #367
+* [ENHANCEMENT] Improved label validation. #274 #335
+* [BUGFIX] Creating a const metric with an invalid `Desc` returns an error. #460
+* [BUGFIX] Histogram observations don't race any longer with exposition. #275
+* [BUGFIX] Fixed goroutine leaks. #236 #472
+* [BUGFIX] Fixed an error message for exponential histogram buckets. #467
+* [BUGFIX] Fixed data race writing to the metric map. #401
+* [BUGFIX] API client: Decode JSON on a 4xx respons but do not on 204
+  responses. #476 #414
+
 ## 0.8.0 / 2016-08-17
 * [CHANGE] Registry is doing more consistency checks. This might break
   existing setups that used to export inconsistent metrics.

vendor/github.com/prometheus/client_golang/ISSUE_TEMPLATE.md

@@ -1,8 +0,0 @@
-<!--
-
-    If you are unhappy how your favorite Go dependency management tool deals
-    with this repository, please do not file an issue but read
-    https://github.com/prometheus/client_golang#important-note-about-releases-versioning-tagging-stability-and-your-favorite-go-dependency-management-tool
-    instead. Thank you very much.
-
--->

vendor/github.com/prometheus/client_golang/Makefile.common

@@ -16,7 +16,7 @@
 # !!! Open PRs only against the prometheus/prometheus/Makefile.common repository!
 
 # Example usage :
-# Create the main Makefile in the root project directory. 
+# Create the main Makefile in the root project directory.
 # include Makefile.common
 # customTarget:
 # 	@echo ">> Running customTarget"
@@ -28,18 +28,53 @@ unexport GOBIN
 GO           ?= go
 GOFMT        ?= $(GO)fmt
 FIRST_GOPATH := $(firstword $(subst :, ,$(shell $(GO) env GOPATH)))
+GOOPTS       ?=
+
+GO_VERSION        ?= $(shell $(GO) version)
+GO_VERSION_NUMBER ?= $(word 3, $(GO_VERSION))
+PRE_GO_111        ?= $(shell echo $(GO_VERSION_NUMBER) | grep -E 'go1\.(10|[0-9])\.')
+
+unexport GOVENDOR
+ifeq (, $(PRE_GO_111))
+	ifneq (,$(wildcard go.mod))
+		# Enforce Go modules support just in case the directory is inside GOPATH (and for Travis CI).
+		GO111MODULE := on
+
+		ifneq (,$(wildcard vendor))
+			# Always use the local vendor/ directory to satisfy the dependencies.
+			GOOPTS := $(GOOPTS) -mod=vendor
+		endif
+	endif
+else
+	ifneq (,$(wildcard go.mod))
+		ifneq (,$(wildcard vendor))
+$(warning This repository requires Go >= 1.11 because of Go modules)
+$(warning Some recipes may not work as expected as the current Go runtime is '$(GO_VERSION_NUMBER)')
+		endif
+	else
+		# This repository isn't using Go modules (yet).
+		GOVENDOR := $(FIRST_GOPATH)/bin/govendor
+	endif
+
+	unexport GO111MODULE
+endif
 PROMU        := $(FIRST_GOPATH)/bin/promu
 STATICCHECK  := $(FIRST_GOPATH)/bin/staticcheck
-GOVENDOR     := $(FIRST_GOPATH)/bin/govendor
 pkgs          = ./...
 
+GO_VERSION        ?= $(shell $(GO) version)
+GO_BUILD_PLATFORM ?= $(subst /,-,$(lastword $(GO_VERSION)))
+
+PROMU_VERSION ?= 0.2.0
+PROMU_URL     := https://github.com/prometheus/promu/releases/download/v$(PROMU_VERSION)/promu-$(PROMU_VERSION).$(GO_BUILD_PLATFORM).tar.gz
+
 PREFIX                  ?= $(shell pwd)
 BIN_DIR                 ?= $(shell pwd)
 DOCKER_IMAGE_TAG        ?= $(subst /,-,$(shell git rev-parse --abbrev-ref HEAD))
 DOCKER_REPO             ?= prom
 
 .PHONY: all
-all: style staticcheck unused build test
+all: precheck style staticcheck unused build test
 
 # This rule is used to forward a target like "build" to "common-build".  This
 # allows a new "build" target to be defined in a Makefile which includes this
@@ -70,37 +105,54 @@ common-check_license:
 .PHONY: common-test-short
 common-test-short:
 	@echo ">> running short tests"
-	$(GO) test -short $(pkgs)
+	GO111MODULE=$(GO111MODULE) $(GO) test -short $(GOOPTS) $(pkgs)
 
 .PHONY: common-test
 common-test:
 	@echo ">> running all tests"
-	$(GO) test -race $(pkgs)
+	GO111MODULE=$(GO111MODULE) $(GO) test -race $(GOOPTS) $(pkgs)
 
 .PHONY: common-format
 common-format:
 	@echo ">> formatting code"
-	$(GO) fmt $(pkgs)
+	GO111MODULE=$(GO111MODULE) $(GO) fmt $(GOOPTS) $(pkgs)
 
 .PHONY: common-vet
 common-vet:
 	@echo ">> vetting code"
-	$(GO) vet $(pkgs)
+	GO111MODULE=$(GO111MODULE) $(GO) vet $(GOOPTS) $(pkgs)
 
 .PHONY: common-staticcheck
 common-staticcheck: $(STATICCHECK)
 	@echo ">> running staticcheck"
+ifdef GO111MODULE
+	GO111MODULE=$(GO111MODULE) $(STATICCHECK) -ignore "$(STATICCHECK_IGNORE)" -checks "SA*" $(pkgs)
+else
 	$(STATICCHECK) -ignore "$(STATICCHECK_IGNORE)" $(pkgs)
+endif
 
 .PHONY: common-unused
 common-unused: $(GOVENDOR)
+ifdef GOVENDOR
 	@echo ">> running check for unused packages"
 	@$(GOVENDOR) list +unused | grep . && exit 1 || echo 'No unused packages'
+else
+ifdef GO111MODULE
+	@echo ">> running check for unused/missing packages in go.mod"
+	GO111MODULE=$(GO111MODULE) $(GO) mod tidy
+	@git diff --exit-code -- go.sum go.mod
+ifneq (,$(wildcard vendor))
+	@echo ">> running check for unused packages in vendor/"
+	GO111MODULE=$(GO111MODULE) $(GO) mod vendor
+	@git diff --exit-code -- go.sum go.mod vendor/
+endif
+endif
+endif
 
 .PHONY: common-build
 common-build: promu
 	@echo ">> building binaries"
-	$(PROMU) build --prefix $(PREFIX)
+	GO111MODULE=$(GO111MODULE) $(PROMU) build --prefix $(PREFIX)
 
 .PHONY: common-tarball
 common-tarball: promu
@@ -120,13 +172,52 @@ common-docker-tag-latest:
 	docker tag "$(DOCKER_REPO)/$(DOCKER_IMAGE_NAME):$(DOCKER_IMAGE_TAG)" "$(DOCKER_REPO)/$(DOCKER_IMAGE_NAME):latest"
 
 .PHONY: promu
-promu:
-	GOOS= GOARCH= $(GO) get -u github.com/prometheus/promu
+promu: $(PROMU)
+
+$(PROMU):
+	curl -s -L $(PROMU_URL) | tar -xvz -C /tmp
+	mkdir -v -p $(FIRST_GOPATH)/bin
+	cp -v /tmp/promu-$(PROMU_VERSION).$(GO_BUILD_PLATFORM)/promu $(PROMU)
+
+.PHONY: proto
+proto:
+	@echo ">> generating code from proto files"
+	@./scripts/genproto.sh
 
 .PHONY: $(STATICCHECK)
 $(STATICCHECK):
-	GOOS= GOARCH= $(GO) get -u honnef.co/go/tools/cmd/staticcheck
+ifdef GO111MODULE
+# Get staticcheck from a temporary directory to avoid modifying the local go.{mod,sum}.
+# See https://github.com/golang/go/issues/27643.
+# For now, we are using the next branch of staticcheck because master isn't compatible yet with Go modules.
+	tmpModule=$$(mktemp -d 2>&1) && \
+	mkdir -p $${tmpModule}/staticcheck && \
+	cd "$${tmpModule}"/staticcheck && \
+	GO111MODULE=on $(GO) mod init example.com/staticcheck && \
+	GO111MODULE=on GOOS= GOARCH= $(GO) get -u honnef.co/go/tools/cmd/staticcheck@next && \
+	rm -rf $${tmpModule};
+else
+	GOOS= GOARCH= GO111MODULE=off $(GO) get -u honnef.co/go/tools/cmd/staticcheck
+endif
 
+ifdef GOVENDOR
 .PHONY: $(GOVENDOR)
 $(GOVENDOR):
 	GOOS= GOARCH= $(GO) get -u github.com/kardianos/govendor
+endif
+
+.PHONY: precheck
+precheck::
+
+define PRECHECK_COMMAND_template =
+precheck:: $(1)_precheck
+
+
+PRECHECK_COMMAND_$(1) ?= $(1) $$(strip $$(PRECHECK_OPTIONS_$(1)))
+.PHONY: $(1)_precheck
+$(1)_precheck:
+	@if ! $$(PRECHECK_COMMAND_$(1)) 1>/dev/null 2>&1; then \
+		echo "Execution of '$$(PRECHECK_COMMAND_$(1))' command failed. Is $(1) installed?"; \
+		exit 1; \
+	fi
+endef

vendor/github.com/prometheus/client_golang/README.md

@@ -11,7 +11,7 @@ Prometheus HTTP API.
 
 __This library requires Go1.7 or later.__
 
-## Important note about releases, versioning, tagging, stability, and your favorite Go dependency management tool
+## Important note about releases, versioning, tagging, and stability
 
 While our goal is to follow [Semantic Versioning](https://semver.org/), this
 repository is still pre-1.0.0. To quote the
@@ -22,38 +22,42 @@ declaring something 1.0.0 doesn't make it 1.0.0. Instead, we are working
 towards a 1.0.0 release that actually deserves its major version number.
 
 Having said that, we aim for always keeping the tip of master in a workable
-state and for only introducing ”mildly” breaking changes up to and including
-[v0.9.0](https://github.com/prometheus/client_golang/milestone/1). After that,
-a number of ”hard” breaking changes are planned, see the
-[v0.10.0 milestone](https://github.com/prometheus/client_golang/milestone/2),
-which should get the library much closer to 1.0.0 state.
+state. We occasionally tag versions and track their changes in CHANGELOG.md,
+but this happens mostly to keep dependency management tools happy and to give
+people a handle they can talk about easily. In particular, all commits in the
+master branch have passed the same testing and reviewing. There is no QA
+process in place that would render tagged commits more stable or better tested
+than others.
 
-Dependency management in Go projects is still in flux, and there are many tools
-floating around. While [dep](https://golang.github.io/dep/) might develop into
-the de-facto standard tool, it is still officially experimental. The roadmap
-for this library has been laid out with a lot of sometimes painful experience
-in mind. We really cannot adjust it every other month to the needs of the
-currently most popular or most promising Go dependency management tool. The
-recommended course of action with dependency management tools is the following:
+There is a plan behind the current (pre-1.0.0) versioning, though:
 
-- Do not expect strict post-1.0.0 semver semantics prior to the 1.0.0
-  release. If your dependency management tool expects strict post-1.0.0 semver
-  semantics, you have to wait. Sorry.
-- If you want absolute certainty, please lock to a specific commit. You can
-  also lock to tags, but please don't ask for more tagging. This would suggest
-  some release or stability testing procedure that simply is not in place. As
-  said above, we are aiming for stability of the tip of master, but if we
-  tagged every single commit, locking to tags would be the same as locking to
-  commits.
-- If you want to get the newer features and improvements and are willing to
-  take the minor risk of newly introduced bugs and “mild” breakage, just always
-  update to the tip of master (which is essentially the original idea of Go
-  dependency management). We recommend to not use features marked as
-  _deprecated_ in this case.
-- Once [v0.9.0](https://github.com/prometheus/client_golang/milestone/1) is
-  out, you could lock to v0.9.x to get bugfixes (and perhaps minor new
-  features) while avoiding the “hard” breakage that will come with post-0.9
-  features.
+- v0.9 is the “production release”, currently tracked in the master
+  branch. “Patch” releases will usually be just bug fixes, indeed, but
+  important new features that do not require invasive code changes might also
+  be included in those. We do not plan any breaking changes from one v0.9.x
+  release to any later v0.9.y release, but nothing is guaranteed. Since the
+  master branch will eventually be switched over to track the upcoming v0.10
+  (see below), we recommend to tell your dependency management tool of choice
+  to use the latest v0.9.x release, at least for your production software. In
+  that way, you should get bug fixes and non-invasive, low-risk new features
+  without the need to change anything on your part.
+- v0.10 is a planned release that will have a _lot_ of breaking changes
+  (despite being only a “minor” release in the Semantic Versioning terminology,
+  but as said, pre-1.0.0 means nothing is guaranteed). Essentially, we have
+  been piling up feature requests that require breaking changes for a while,
+  and they are all collected in the
+  [v0.10 milestone](https://github.com/prometheus/client_golang/milestone/2).
+  Since there will be so many breaking changes, the development for v0.10 is
+  currently not happening in the master branch, but in the
+  [dev-0.10 branch](https://github.com/prometheus/client_golang/tree/dev-0.10).
+  It will violently change for a while, and it will definitely be in a
+  non-working state now and then. It should only be used for sneak-peaks and
+  discussions of the new features and designs.
+- Once v0.10 is ready for real-life use, it will be merged into the master
+  branch (which is the reason why you should lock your dependency management
+  tool to v0.9.x and only migrate to v0.10 when both you and v0.10 are ready
+  for it). In the ideal case, v0.10 will be the basis for the future v1.0
+  release, but we cannot provide an ETA at this time.
 
 ## Instrumenting applications
 
@@ -62,8 +66,8 @@ recommended course of action with dependency management tools is the following:
 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)

vendor/github.com/prometheus/client_golang/VERSION

@@ -1 +1 @@
-0.8.0
+0.9.1

vendor/github.com/prometheus/client_golang/go.mod

@@ -0,0 +1,12 @@
+module github.com/prometheus/client_golang
+
+require (
+	github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973
+	github.com/golang/protobuf v1.2.0
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910
+	github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce
+	github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d
+	golang.org/x/net v0.0.0-20181114220301-adae6a3d119a
+	golang.org/x/sync v0.0.0-20181108010431-42b317875d0f // indirect
+)

vendor/github.com/prometheus/client_golang/go.sum

@@ -0,0 +1,16 @@
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973 h1:xJ4a3vCFaGF/jqvzLMYoU8P317H5OQ+Via4RmuPwCS0=
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
+github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce h1:X0jFYGnHemYDIW6jlc+fSI8f9Cg+jqCnClYP2WgZT/A=
+github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d h1:GoAlyOgbOEIFdaDqxJVlbOQ1DtGmZWs/Qau0hIlk+WQ=
+github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+golang.org/x/net v0.0.0-20181114220301-adae6a3d119a h1:gOpx8G595UYyvj8UK4+OFyY4rx037g3fmfhe5SasG3U=
+golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f h1:Bl/8QSvNqXvPGPGXa2z5xUTmV7VDcZyvRZ+QQXkXTZQ=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=

vendor/github.com/prometheus/client_golang/prometheus/collector.go

@@ -40,7 +40,8 @@ type Collector interface {
 	// Collector may yield any Metric it sees fit in its Collect method.
 	//
 	// This method idempotently sends the same descriptors throughout the
-	// lifetime of the Collector.
+	// lifetime of the Collector. It may be called concurrently and
+	// therefore must be implemented in a concurrency safe way.
 	//
 	// If a Collector encounters an error while executing this method, it
 	// must send an invalid descriptor (created with NewInvalidDesc) to

vendor/github.com/prometheus/client_golang/prometheus/counter.go

@@ -136,7 +136,7 @@ func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
 	return &CounterVec{
 		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
 			if len(lvs) != len(desc.variableLabels) {
-				panic(errInconsistentCardinality)
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
 			}
 			result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
 			result.init(result) // Init self-collection.

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -93,7 +93,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 	// First add only the const label names and sort them...
 	for labelName := range constLabels {
 		if !checkLabelName(labelName) {
-			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
 			return d
 		}
 		labelNames = append(labelNames, labelName)
@@ -115,7 +115,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 	// dimension with a different mix between preset and variable labels.
 	for _, labelName := range variableLabels {
 		if !checkLabelName(labelName) {
-			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
 			return d
 		}
 		labelNames = append(labelNames, "$"+labelName)

vendor/github.com/prometheus/client_golang/prometheus/gauge.go

@@ -147,7 +147,7 @@ func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
 	return &GaugeVec{
 		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
 			if len(lvs) != len(desc.variableLabels) {
-				panic(errInconsistentCardinality)
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
 			}
 			result := &gauge{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
 			result.init(result) // Init self-collection.

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -165,7 +165,7 @@ func NewHistogram(opts HistogramOpts) Histogram {
 
 func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram {
 	if len(desc.variableLabels) != len(labelValues) {
-		panic(errInconsistentCardinality)
+		panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues))
 	}
 
 	for _, n := range desc.variableLabels {

vendor/github.com/prometheus/client_golang/prometheus/http.go

@@ -15,9 +15,7 @@ package prometheus
 
 import (
 	"bufio"
-	"bytes"
 	"compress/gzip"
-	"fmt"
 	"io"
 	"net"
 	"net/http"
@@ -41,19 +39,10 @@ const (
 	acceptEncodingHeader  = "Accept-Encoding"
 )
 
-var bufPool sync.Pool
-
-func getBuf() *bytes.Buffer {
-	buf := bufPool.Get()
-	if buf == nil {
-		return &bytes.Buffer{}
-	}
-	return buf.(*bytes.Buffer)
-}
-
-func giveBuf(buf *bytes.Buffer) {
-	buf.Reset()
-	bufPool.Put(buf)
+var gzipPool = sync.Pool{
+	New: func() interface{} {
+		return gzip.NewWriter(nil)
+	},
 }
 
 // Handler returns an HTTP handler for the DefaultGatherer. It is
@@ -71,58 +60,40 @@ func Handler() http.Handler {
 // Deprecated: Use promhttp.HandlerFor(DefaultGatherer, promhttp.HandlerOpts{})
 // instead. See there for further documentation.
 func UninstrumentedHandler() http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+	return http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
 		mfs, err := DefaultGatherer.Gather()
 		if err != nil {
-			http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError)
+			httpError(rsp, err)
 			return
 		}
 
 		contentType := expfmt.Negotiate(req.Header)
-		buf := getBuf()
-		defer giveBuf(buf)
-		writer, encoding := decorateWriter(req, buf)
-		enc := expfmt.NewEncoder(writer, contentType)
-		var lastErr error
+		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 {
-				lastErr = err
-				http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
+				httpError(rsp, err)
 				return
 			}
 		}
-		if closer, ok := writer.(io.Closer); ok {
-			closer.Close()
-		}
-		if lastErr != nil && buf.Len() == 0 {
-			http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
-			return
-		}
-		header := w.Header()
-		header.Set(contentTypeHeader, string(contentType))
-		header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
-		if encoding != "" {
-			header.Set(contentEncodingHeader, encoding)
-		}
-		w.Write(buf.Bytes())
 	})
 }
 
-// decorateWriter wraps a writer to handle gzip compression if requested.  It
-// returns the decorated writer and the appropriate "Content-Encoding" header
-// (which is empty if no compression is enabled).
-func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
-	header := request.Header.Get(acceptEncodingHeader)
-	parts := strings.Split(header, ",")
-	for _, part := range parts {
-		part = strings.TrimSpace(part)
-		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
-			return gzip.NewWriter(writer), "gzip"
-		}
-	}
-	return writer, ""
-}
-
 var instLabels = []string{"method", "code"}
 
 type nower interface {
@@ -503,3 +474,31 @@ func sanitizeCode(s int) string {
 		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,
+	)
+}

vendor/github.com/prometheus/client_golang/prometheus/labels.go

@@ -37,9 +37,22 @@ const reservedLabelPrefix = "__"
 
 var errInconsistentCardinality = errors.New("inconsistent label cardinality")
 
+func makeInconsistentCardinalityError(fqName string, labels, labelValues []string) error {
+	return fmt.Errorf(
+		"%s: %q has %d variable labels named %q but %d values %q were provided",
+		errInconsistentCardinality, fqName,
+		len(labels), labels,
+		len(labelValues), labelValues,
+	)
+}
+
 func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
 	if len(labels) != expectedNumberOfValues {
-		return errInconsistentCardinality
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(labels), labels,
+		)
 	}
 
 	for name, val := range labels {
@@ -53,7 +66,11 @@ func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
 
 func validateLabelValues(vals []string, expectedNumberOfValues int) error {
 	if len(vals) != expectedNumberOfValues {
-		return errInconsistentCardinality
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(vals), vals,
+		)
 	}
 
 	for _, val := range vals {

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -32,7 +32,6 @@
 package promhttp
 
 import (
-	"bytes"
 	"compress/gzip"
 	"fmt"
 	"io"
@@ -53,19 +52,10 @@ const (
 	acceptEncodingHeader  = "Accept-Encoding"
 )
 
-var bufPool sync.Pool
-
-func getBuf() *bytes.Buffer {
-	buf := bufPool.Get()
-	if buf == nil {
-		return &bytes.Buffer{}
-	}
-	return buf.(*bytes.Buffer)
-}
-
-func giveBuf(buf *bytes.Buffer) {
-	buf.Reset()
-	bufPool.Put(buf)
+var gzipPool = sync.Pool{
+	New: func() interface{} {
+		return gzip.NewWriter(nil)
+	},
 }
 
 // Handler returns an http.Handler for the prometheus.DefaultGatherer, using
@@ -100,19 +90,18 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
 		inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
 	}
 
-	h := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+	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(w, fmt.Sprintf(
+				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 {
@@ -123,26 +112,40 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
 				panic(err)
 			case ContinueOnError:
 				if len(mfs) == 0 {
-					http.Error(w, "No metrics gathered, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+					// Still report the error if no metrics have been gathered.
+					httpError(rsp, err)
 					return
 				}
 			case HTTPErrorOnError:
-				http.Error(w, "An error has occurred during metrics gathering:\n\n"+err.Error(), http.StatusInternalServerError)
+				httpError(rsp, err)
 				return
 			}
 		}
 
 		contentType := expfmt.Negotiate(req.Header)
-		buf := getBuf()
-		defer giveBuf(buf)
-		writer, encoding := decorateWriter(req, buf, opts.DisableCompression)
-		enc := expfmt.NewEncoder(writer, contentType)
+		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 metric family:", err)
+					opts.ErrorLog.Println("error encoding and sending metric family:", err)
 				}
 				switch opts.ErrorHandling {
 				case PanicOnError:
@@ -150,28 +153,15 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
 				case ContinueOnError:
 					// Handled later.
 				case HTTPErrorOnError:
-					http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
+					httpError(rsp, err)
 					return
 				}
 			}
 		}
-		if closer, ok := writer.(io.Closer); ok {
-			closer.Close()
+
+		if lastErr != nil {
+			httpError(rsp, lastErr)
 		}
-		if lastErr != nil && buf.Len() == 0 {
-			http.Error(w, "No metrics encoded, last error:\n\n"+lastErr.Error(), http.StatusInternalServerError)
-			return
-		}
-		header := w.Header()
-		header.Set(contentTypeHeader, string(contentType))
-		header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
-		if encoding != "" {
-			header.Set(contentEncodingHeader, encoding)
-		}
-		if _, err := w.Write(buf.Bytes()); err != nil && opts.ErrorLog != nil {
-			opts.ErrorLog.Println("error while sending encoded metrics:", err)
-		}
-		// TODO(beorn7): Consider streaming serving of metrics.
 	})
 
 	if opts.Timeout <= 0 {
@@ -292,20 +282,30 @@ type HandlerOpts struct {
 	Timeout time.Duration
 }
 
-// decorateWriter wraps a writer to handle gzip compression if requested.  It
-// returns the decorated writer and the appropriate "Content-Encoding" header
-// (which is empty if no compression is enabled).
-func decorateWriter(request *http.Request, writer io.Writer, compressionDisabled bool) (io.Writer, string) {
-	if compressionDisabled {
-		return writer, ""
-	}
-	header := request.Header.Get(acceptEncodingHeader)
-	parts := strings.Split(header, ",")
+// 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 gzip.NewWriter(writer), "gzip"
+			return true
 		}
 	}
-	return writer, ""
+	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,
+	)
 }

vendor/github.com/prometheus/client_golang/prometheus/registry.go

@@ -16,6 +16,9 @@ package prometheus
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
 	"runtime"
 	"sort"
 	"strings"
@@ -23,6 +26,7 @@ import (
 	"unicode/utf8"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/expfmt"
 
 	dto "github.com/prometheus/client_model/go"
 
@@ -107,9 +111,6 @@ type Registerer interface {
 	// Collector, and for providing a Collector that will not cause
 	// inconsistent metrics on collection. (This would lead to scrape
 	// errors.)
-	//
-	// It is in general not safe to register the same Collector multiple
-	// times concurrently.
 	Register(Collector) error
 	// MustRegister works like Register but registers any number of
 	// Collectors and panics upon the first registration that causes an
@@ -273,7 +274,12 @@ func (r *Registry) Register(c Collector) error {
 		close(descChan)
 	}()
 	r.mtx.Lock()
-	defer r.mtx.Unlock()
+	defer func() {
+		// Drain channel in case of premature return to not leak a goroutine.
+		for range descChan {
+		}
+		r.mtx.Unlock()
+	}()
 	// Conduct various tests...
 	for desc := range descChan {
 
@@ -531,6 +537,38 @@ func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
 	return internal.NormalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
 }
 
+// WriteToTextfile calls Gather on the provided Gatherer, encodes the result in the
+// Prometheus text format, and writes it to a temporary file. Upon success, the
+// temporary file is renamed to the provided filename.
+//
+// This is intended for use with the textfile collector of the node exporter.
+// Note that the node exporter expects the filename to be suffixed with ".prom".
+func WriteToTextfile(filename string, g Gatherer) error {
+	tmp, err := ioutil.TempFile(filepath.Dir(filename), filepath.Base(filename))
+	if err != nil {
+		return err
+	}
+	defer os.Remove(tmp.Name())
+
+	mfs, err := g.Gather()
+	if err != nil {
+		return err
+	}
+	for _, mf := range mfs {
+		if _, err := expfmt.MetricFamilyToText(tmp, mf); err != nil {
+			return err
+		}
+	}
+	if err := tmp.Close(); err != nil {
+		return err
+	}
+
+	if err := os.Chmod(tmp.Name(), 0644); err != nil {
+		return err
+	}
+	return os.Rename(tmp.Name(), filename)
+}
+
 // processMetric is an internal helper method only used by the Gather method.
 func processMetric(
 	metric Metric,
@@ -785,6 +823,8 @@ func checkMetricConsistency(
 	dtoMetric *dto.Metric,
 	metricHashes map[uint64]struct{},
 ) error {
+	name := metricFamily.GetName()
+
 	// Type consistency with metric family.
 	if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil ||
 		metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil ||
@@ -793,33 +833,42 @@ func checkMetricConsistency(
 		metricFamily.GetType() == dto.MetricType_UNTYPED && dtoMetric.Untyped == nil {
 		return fmt.Errorf(
 			"collected metric %q { %s} is not a %s",
-			metricFamily.GetName(), dtoMetric, metricFamily.GetType(),
+			name, dtoMetric, metricFamily.GetType(),
 		)
 	}
 
+	previousLabelName := ""
 	for _, labelPair := range dtoMetric.GetLabel() {
-		if !checkLabelName(labelPair.GetName()) {
+		labelName := labelPair.GetName()
+		if labelName == previousLabelName {
 			return fmt.Errorf(
-				"collected metric %q { %s} has a label with an invalid name: %s",
-				metricFamily.GetName(), dtoMetric, labelPair.GetName(),
+				"collected metric %q { %s} has two or more labels with the same name: %s",
+				name, dtoMetric, labelName,
 			)
 		}
-		if dtoMetric.Summary != nil && labelPair.GetName() == quantileLabel {
+		if !checkLabelName(labelName) {
+			return fmt.Errorf(
+				"collected metric %q { %s} has a label with an invalid name: %s",
+				name, dtoMetric, labelName,
+			)
+		}
+		if dtoMetric.Summary != nil && labelName == quantileLabel {
 			return fmt.Errorf(
 				"collected metric %q { %s} must not have an explicit %q label",
-				metricFamily.GetName(), dtoMetric, quantileLabel,
+				name, dtoMetric, quantileLabel,
 			)
 		}
 		if !utf8.ValidString(labelPair.GetValue()) {
 			return fmt.Errorf(
 				"collected metric %q { %s} has a label named %q whose value is not utf8: %#v",
-				metricFamily.GetName(), dtoMetric, labelPair.GetName(), labelPair.GetValue())
+				name, dtoMetric, labelName, labelPair.GetValue())
 		}
+		previousLabelName = labelName
 	}
 
 	// Is the metric unique (i.e. no other metric with the same name and the same labels)?
 	h := hashNew()
-	h = hashAdd(h, metricFamily.GetName())
+	h = hashAdd(h, name)
 	h = hashAddByte(h, separatorByte)
 	// Make sure label pairs are sorted. We depend on it for the consistency
 	// check.
@@ -833,7 +882,7 @@ func checkMetricConsistency(
 	if _, exists := metricHashes[h]; exists {
 		return fmt.Errorf(
 			"collected metric %q { %s} was collected before with the same name and label values",
-			metricFamily.GetName(), dtoMetric,
+			name, dtoMetric,
 		)
 	}
 	metricHashes[h] = struct{}{}

vendor/github.com/prometheus/client_golang/prometheus/summary.go

@@ -181,7 +181,7 @@ func NewSummary(opts SummaryOpts) Summary {
 
 func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 	if len(desc.variableLabels) != len(labelValues) {
-		panic(errInconsistentCardinality)
+		panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues))
 	}
 
 	for _, n := range desc.variableLabels {