Remove Windows platform support, add the Golangci check code, compile…

.gitignore

@@ -4,4 +4,5 @@ vendor
 .vscode
 .DS_Store
 beat-exporter
-beat-exporter.exe
+beat-exporter.exe
+/bin

.golangci.yaml

@@ -0,0 +1,22 @@
+linters-settings:
+  golint:
+    min-confidence: 0
+  misspell:
+    locale: US
+linters:
+  disable-all: true
+  enable:
+    - typecheck
+    - varcheck
+    - goimports
+    - misspell
+    - govet
+    - golint
+    - ineffassign
+    - gosimple
+    - deadcode
+    - structcheck
+    - unused
+    - errcheck
+service:
+  golangci-lint-version: 1.41.1 # use the fixed version to not introduce new linters unexpectedly

Dockerfile

@@ -1,7 +1,20 @@
-FROM quay.io/prometheus/busybox:latest
-LABEL MAINTAINER="Audrius Karabanovas <[email protected]>"
+FROM golang:1.16.10-alpine3.13 AS builder
 
-COPY .build/linux-amd64/beat-exporter /bin/beat-exporter
+WORKDIR /root/go/src/beat-exporter
 
-EXPOSE      9479
-ENTRYPOINT  [ "/bin/beat-exporter" ]
+ENV GOPROXY https://goproxy.cn
+ENV GOPATH /root/go
+COPY go.mod .
+COPY go.sum .
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -a -o beat-exporter
+
+FROM alpine:3.13 AS final
+
+WORKDIR /bin
+COPY --from=builder /root/go/src/beat-exporter/beat-exporter /bin/
+
+EXPOSE 9479
+ENTRYPOINT ["/bin/beat-exporter"]

Makefile

@@ -0,0 +1,30 @@
+BUILD_BIN_PATH := $(shell pwd)/bin
+BUILD_BIN_NAME := beat-exporter
+
+VERSION_PKG := beat-exporter/internal/service
+
+LD_FLAGS += -X "$(VERSION_PKG).releaseVersion=$(shell git describe --tags --dirty --always)"
+LD_FLAGS += -X "$(VERSION_PKG).buildDate=$(shell date -u '+%Y-%m-%d %I:%M:%S')"
+LD_FLAGS += -X "$(VERSION_PKG).gitHash=$(shell git rev-parse HEAD)"
+LD_FLAGS += -X "$(VERSION_PKG).gitBranch=$(shell git rev-parse --abbrev-ref HEAD)"
+
+GOVER_MAJOR := $(shell go version | sed -E -e "s/.*go([0-9]+)[.]([0-9]+).*/\1/")
+GOVER_MINOR := $(shell go version | sed -E -e "s/.*go([0-9]+)[.]([0-9]+).*/\2/")
+GO111 := $(shell [ $(GOVER_MAJOR) -gt 1 ] || [ $(GOVER_MAJOR) -eq 1 ] && [ $(GOVER_MINOR) -ge 11 ]; echo $$?)
+ifeq ($(GO111), 1)
+  $(error "go below 1.11 does not support modules")
+endif
+
+default: check build
+
+build-deps:
+	@mkdir -p bin
+build: export GO111MODULE=on
+build: build-deps
+	go build -ldflags '$(LD_FLAGS)' -o $(BUILD_BIN_PATH)/$(BUILD_BIN_NAME) main.go
+
+check: check-static
+check-static: tools/bin/golangci-lint
+	tools/bin/golangci-lint run -v --deadline=3m --config ./.golangci.yaml $$($(PACKAGE_DIRECTORIES))
+tools/bin/golangci-lint:
+	curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b ./tools/bin v1.41.1;

go.mod

@@ -1,4 +1,4 @@
-module github.com/trustpilot/beat-exporter
+module beat-exporter
 
 go 1.12
 
@@ -7,5 +7,4 @@ require (
 	github.com/prometheus/client_golang v1.3.0
 	github.com/prometheus/common v0.8.0
 	github.com/sirupsen/logrus v1.4.2
-	golang.org/x/sys v0.0.0-20200113162924-86b910548bc1
 )

go.sum

@@ -47,7 +47,6 @@ github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5Fsn
 github.com/prometheus/client_golang v1.3.0 h1:miYCvYqFXtl/J9FIy8eNpBfYthAEFg+Ys0XyUVEcDsc=
 github.com/prometheus/client_golang v1.3.0/go.mod h1:hJaj2vgQTGQmVCsAACORcieXFeDPbaTKGT+JTgUa3og=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
-github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.1.0 h1:ElTg5tNp4DqfV7UQjDqv2+RJlNzsDtvNAWccbItceIE=
 github.com/prometheus/client_model v0.1.0/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=

internal/service/exporter.go

@@ -0,0 +1,135 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+
+	"beat-exporter/collector"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/version"
+	log "github.com/sirupsen/logrus"
+)
+
+type Params struct {
+	ServiceName   string
+	ListenAddress string
+	TLSCertFile   string
+	TLSKeyFile    string
+	MetricsPath   string
+	BeatURI       string
+	BeatTimeout   time.Duration
+	SystemBeat    bool
+}
+
+func NewParams(
+	listenAddress,
+	tlsCertFile,
+	tlsKeyFile,
+	metricsPath,
+	beatURI string,
+	BeatTimeout time.Duration,
+	systemBeat bool) *Params {
+	return &Params{
+		ServiceName:   "beat_exporter",
+		ListenAddress: listenAddress,
+		TLSCertFile:   tlsCertFile,
+		TLSKeyFile:    tlsKeyFile,
+		MetricsPath:   metricsPath,
+		BeatURI:       beatURI,
+		BeatTimeout:   BeatTimeout,
+		SystemBeat:    systemBeat,
+	}
+}
+
+type Exporter struct {
+	ServiceParams      *Params
+	BeatURL            *url.URL
+	HTTPClient         *http.Client
+	BeatInfo           *collector.BeatInfo
+	PrometheusRegistry *prometheus.Registry
+}
+
+func NewExporter(params *Params) *Exporter {
+	exporter := &Exporter{ServiceParams: params}
+	beatURL, err := url.Parse(exporter.ServiceParams.BeatURI)
+	if err != nil {
+		log.Fatalf("failed to parse beat.uri, error: %v", err)
+		panic(err)
+	}
+	exporter.BeatURL = beatURL
+	exporter.HTTPClient = &http.Client{
+		Timeout: exporter.ServiceParams.BeatTimeout,
+	}
+
+	exporter.handleURL()
+	exporter.loadBeatInfo()
+	exporter.loadPrometheusRegistry()
+	return exporter
+}
+
+func (e *Exporter) handleURL() {
+	if e.BeatURL.Scheme == "unix" {
+		unixPath := e.BeatURL.Path
+		e.BeatURL.Scheme = "http"
+		e.BeatURL.Host = "localhost"
+		e.BeatURL.Path = ""
+		e.HTTPClient.Transport = &http.Transport{
+			DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
+				return (&net.Dialer{}).DialContext(ctx, "unix", unixPath)
+			},
+		}
+	}
+}
+
+func (e *Exporter) loadBeatInfo() {
+	response, err := e.HTTPClient.Get(e.BeatURL.String())
+	if err != nil {
+		log.Errorf("Could not load beat type, with error: %v", err)
+		panic(err)
+	}
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusOK {
+		log.Errorf("Beat URL: %q status code: %d", e.BeatURL.String(), response.StatusCode)
+		panic(err)
+	}
+
+	bodyBytes, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		log.Error("Can't read body of response")
+		panic(err)
+	}
+
+	beatInfo := &collector.BeatInfo{}
+	if err := json.Unmarshal(bodyBytes, &beatInfo); err != nil {
+		log.Error("Could not parse JSON response for target")
+		panic(err)
+	}
+
+	log.WithFields(
+		log.Fields{
+			"beat":     beatInfo.Beat,
+			"version":  beatInfo.Version,
+			"name":     beatInfo.Name,
+			"hostname": beatInfo.Hostname,
+			"uuid":     beatInfo.UUID,
+		}).Info("Target beat configuration loaded successfully!")
+
+	e.BeatInfo = beatInfo
+}
+
+func (e *Exporter) loadPrometheusRegistry() {
+	params := e.ServiceParams
+	// version metric
+	e.PrometheusRegistry = prometheus.NewRegistry()
+	versionMetric := version.NewCollector(params.ServiceName)
+	mainCollector := collector.NewMainCollector(e.HTTPClient, e.BeatURL, params.ServiceName, e.BeatInfo, params.SystemBeat)
+	e.PrometheusRegistry.MustRegister(versionMetric)
+	e.PrometheusRegistry.MustRegister(mainCollector)
+}