[Feature] Add License, JWT Token Refresh and several fixes

LICENSE.BOILERPLATE

@@ -0,0 +1,19 @@
+
+DISCLAIMER
+
+Copyright 2020 ArangoDB GmbH, Cologne, Germany
+
+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.
+
+Copyright holder is ArangoDB GmbH, Cologne, Germany
+

Makefile

@@ -44,6 +44,8 @@ DOCKERIMAGE := $(DOCKERNAMESPACE)/arangodb-exporter:$(DOCKERTAG)
 RELEASE := $(SRCDIR)/bin/release$(shell go env GOEXE)
 GHRELEASE := $(SRCDIR)/bin/github-release$(shell go env GOEXE)
 GOX := $(SRCDIR)/bin/gox$(shell go env GOEXE)
+GOIMPORTS := $(SRCDIR)/bin/fmt$(shell go env GOEXE)
+ADDLICENSE := $(SRCDIR)/bin/addlicense$(shell go env GOEXE)
 
 # Magical rubbish to teach make what commas and spaces are.
 EMPTY :=
@@ -53,6 +55,12 @@ COMMA := $(EMPTY),$(EMPTY)
 ARCHS:=amd64 arm arm64
 PLATFORMS:=$(subst $(SPACE),$(COMMA),$(foreach arch,$(ARCHS),linux/$(arch)))
 
+GO_IGNORED:=vendor .gobuild
+
+GO_SOURCES_QUERY := find $(SRCDIR) -name '*.go' -type f $(foreach IGNORED,$(GO_IGNORED),-not -path '$(SRCDIR)/$(IGNORED)/*' )
+GO_SOURCES := $(shell $(GO_SOURCES_QUERY) | sort | uniq)
+GO_SOURCES_PACKAGES := $(shell $(GO_SOURCES_QUERY) -exec dirname {} \; | sort | uniq)
+
 SOURCES := $(shell find $(SRCDIR) -name '*.go' -not -path './test/*')
 
 .PHONY: all clean build docker
@@ -91,31 +99,45 @@ docker-ubi-base: check-vars
 	docker build --no-cache -t $(DOCKERIMAGE)-base-image-ubi -f Dockerfile.ubi .
 
 docker-ubi: docker-ubi-base build
+ifndef LOCAL
 	for arch in amd64; do \
 		docker build --build-arg "GOARCH=$$arch" --build-arg "VERSION=$(VERSION_MAJOR_MINOR_PATCH)" -t $(DOCKERIMAGE)-ubi --build-arg "BASE_IMAGE=$(DOCKERIMAGE)-base-image-ubi" -f Dockerfile.scratch . ; \
 		docker push $(DOCKERIMAGE)-ubi ; \
 	done
+else
+	for arch in amd64; do \
+		docker build --build-arg "GOARCH=$$arch" --build-arg "VERSION=$(VERSION_MAJOR_MINOR_PATCH)" -t $(DOCKERIMAGE)-ubi --build-arg "BASE_IMAGE=$(DOCKERIMAGE)-base-image-ubi" -f Dockerfile.scratch . ; \
+	done
+endif
 
 ifndef IGNORE_UBI
 docker: docker-ubi
 endif
 
 docker: check-vars build
+ifndef LOCAL
 	for arch in $(ARCHS); do \
 		docker build --build-arg "GOARCH=$$arch" --build-arg "VERSION=$(VERSION_MAJOR_MINOR_PATCH)" -t $(DOCKERIMAGE)-$$arch -f Dockerfile.scratch . ; \
 		docker push $(DOCKERIMAGE)-$$arch ; \
 	done
-	DOCKER_CLI_EXPERIMENTAL=enabled docker manifest create --amend $(DOCKERIMAGE) $(foreach arch,$(ARCHS),$(DOCKERIMAGE)-$(arch)) $(DOCKERIMAGE)-ubi
-	DOCKER_CLI_EXPERIMENTAL=enabled docker manifest push $(DOCKERIMAGE)
+	docker tag $(DOCKERIMAGE)-amd64 $(DOCKERIMAGE)
+	docker push $(DOCKERIMAGE)
+else
+	for arch in $(ARCHS); do \
+		docker build --build-arg "GOARCH=$$arch" --build-arg "VERSION=$(VERSION_MAJOR_MINOR_PATCH)" -t $(DOCKERIMAGE)-$$arch -f Dockerfile.scratch . ; \
+	done
+endif
 
 $(RELEASE): $(GOBUILDDIR) $(SOURCES) $(GHRELEASE)
 	go build -o $(RELEASE) $(REPOPATH)/tools/release
 
-$(GHRELEASE): $(GOBUILDDIR) 
-	go build -o $(GHRELEASE) github.com/aktau/github-release
+$(GHRELEASE): $(GOBUILDDIR)
+	@go build -mod='' -o "$(GHRELEASE)" github.com/aktau/github-release
+
+github-release: $(GHRELEASE)
 
 $(GOX): 
-	go build -o $(GOX) github.com/mitchellh/gox
+	go build -mod='' -o $(GOX) github.com/mitchellh/gox
 
 release-patch: $(RELEASE) $(GHRELEASE)
 	$(RELEASE) -type=patch 
@@ -126,3 +148,48 @@ release-minor: $(RELEASE) $(GHRELEASE)
 release-major: $(RELEASE) $(GHRELEASE)
 	$(RELEASE) -type=major 
 
+## LINT
+
+GOLANGCI_ENABLED=deadcode gocyclo golint varcheck structcheck maligned errcheck \
+                 ineffassign interfacer unconvert goconst \
+                 megacheck
+
+.PHONY: tools
+tools: $(ADDLICENSE) $(GOIMPORTS) $(GHRELEASE)
+
+$(ADDLICENSE):
+	@go build -mod='' -o "$(ADDLICENSE)" github.com/google/addlicense
+
+.PHONY: license
+license: $(ADDLICENSE)
+	@echo ">> Verify license of files"
+	@$(ADDLICENSE) -f "./LICENSE.BOILERPLATE" $(GO_SOURCES)
+
+.PHONY: license-verify
+license-verify: $(ADDLICENSE)
+	@echo ">> Ensuring license of files"
+	@$(ADDLICENSE) -f "./LICENSE.BOILERPLATE" -check $(GO_SOURCES)
+
+$(GOIMPORTS):
+	@go build -mod='' -o "$(GOIMPORTS)" golang.org/x/tools/cmd/goimports
+
+.PHONY: fmt
+fmt: $(GOIMPORTS)
+	@echo ">> Ensuring style of files"
+	@$(GOIMPORTS) -w $(GO_SOURCES)
+
+.PHONY: fmt-verify
+fmt-verify: license-verify $(GOIMPORTS)
+	@echo ">> Verify files style"
+	@if [ X"$$($(GOIMPORTS) -l $(GO_SOURCES) | wc -l)" != X"0" ]; then echo ">> Style errors"; $(GOIMPORTS) -l $(GO_SOURCES); exit 1; fi
+
+.PHONY: linter
+linter: fmt
+	@golangci-lint run --no-config --issues-exit-code=1 --deadline=30m --disable-all \
+	                  $(foreach MODE,$(GOLANGCI_ENABLED),--enable $(MODE) ) \
+	                  --exclude-use-default=false \
+	                  $(GO_SOURCES_PACKAGES)
+
+.PHONY: vendor
+vendor:
+	@go mod vendor

connection.go

@@ -0,0 +1,51 @@
+//
+// DISCLAIMER
+//
+// Copyright 2018 ArangoDB GmbH, Cologne, Germany
+//
+// 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.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+// Author Adam Janikowski
+//
+
+package main
+
+import (
+	"io/ioutil"
+	"strings"
+)
+
+type Authentication func() (string, error)
+
+func newAuthentication() Authentication {
+	if arangodbOptions.jwtFile != "" {
+		return func() (string, error) {
+
+			data, err := ioutil.ReadFile(arangodbOptions.jwtFile)
+			if err != nil {
+				return "", err
+			}
+
+			return strings.TrimSpace(string(data)), nil
+		}
+	} else if arangodbOptions.jwtSecret != "" {
+		return func() (string, error) {
+			return CreateArangodJWT(arangodbOptions.jwtSecret)
+		}
+	}
+	return func() (string, error) {
+		return "", nil
+	}
+}

exporter.go

@@ -92,7 +92,7 @@ func newMetric(group StatisticGroup, figure StatisticFigure) []prometheus.Collec
 // Exporter collects ArangoDB statistics from the given endpoint and exports them using
 // the prometheus metrics package.
 type Exporter struct {
-	conn    driver.Connection
+	factory connClientFactory
 	timeout time.Duration
 	mutex   sync.RWMutex
 
@@ -102,31 +102,10 @@ type Exporter struct {
 }
 
 // NewExporter returns an initialized Exporter.
-func NewExporter(arangodbEndpoint, jwt string, sslVerify bool, timeout time.Duration) (*Exporter, error) {
-	connCfg := driver_http.ConnectionConfig{
-		Endpoints: []string{arangodbEndpoint},
-	}
-	if !sslVerify {
-		connCfg.TLSConfig = &tls.Config{InsecureSkipVerify: true}
-	}
-	conn, err := driver_http.NewConnection(connCfg)
-	if err != nil {
-		return nil, maskAny(err)
-	}
-	if jwt != "" {
-		hdr, err := CreateArangodJwtAuthorizationHeader(jwt)
-		if err != nil {
-			return nil, maskAny(err)
-		}
-		auth := driver.RawAuthentication(hdr)
-		conn, err = conn.SetAuthentication(auth)
-		if err != nil {
-			return nil, maskAny(err)
-		}
-	}
+func NewExporter(arangodbEndpoint string, jwt Authentication, sslVerify bool, timeout time.Duration) (*Exporter, error) {
 
 	return &Exporter{
-		conn:    conn,
+		factory: newConnClientFactory(arangodbEndpoint, jwt, sslVerify, timeout),
 		timeout: timeout,
 		up: prometheus.NewGauge(prometheus.GaugeOpts{
 			Namespace: namespace,
@@ -147,6 +126,42 @@ func NewExporter(arangodbEndpoint, jwt string, sslVerify bool, timeout time.Dura
 	}, nil
 }
 
+type connClientFactory func() (driver.Connection, error)
+
+func newConnClientFactory(arangodbEndpoint string, auth Authentication, sslVerify bool, timeout time.Duration) connClientFactory {
+	return func() (driver.Connection, error) {
+		connCfg := driver_http.ConnectionConfig{
+			Endpoints: []string{arangodbEndpoint},
+		}
+		if !sslVerify {
+			connCfg.TLSConfig = &tls.Config{InsecureSkipVerify: true}
+		}
+
+		jwt, err := auth()
+		if err != nil {
+			return nil, err
+		}
+
+		conn, err := driver_http.NewConnection(connCfg)
+		if err != nil {
+			return nil, maskAny(err)
+		}
+		if jwt != "" {
+			hdr, err := CreateArangodJwtAuthorizationHeader(jwt)
+			if err != nil {
+				return nil, maskAny(err)
+			}
+			auth := driver.RawAuthentication(hdr)
+			conn, err = conn.SetAuthentication(auth)
+			if err != nil {
+				return nil, maskAny(err)
+			}
+		}
+
+		return conn, nil
+	}
+}
+
 // Describe describes all the metrics ever exported by the HAProxy exporter. It
 // implements prometheus.Collector.
 func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
@@ -181,16 +196,23 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 func (e *Exporter) scrape(ctx context.Context) {
 	e.totalScrapes.Inc()
 
+	conn, err := e.factory()
+	if err != nil {
+		e.up.Set(0)
+		log.Errorf("Failed to create client: %v", err)
+		return
+	}
+
 	// Gather descriptions
-	descr, err := GetStatisticsDescription(ctx, e.conn)
+	descr, err := GetStatisticsDescription(ctx, conn)
 	if err != nil {
 		e.up.Set(0)
 		log.Errorf("Failed to fetch statistic descriptions: %v", err)
 		return
 	}
 
 	// Collect statistics
-	stats, err := GetStatistics(ctx, e.conn)
+	stats, err := GetStatistics(ctx, conn)
 	if err != nil {
 		e.up.Set(0)
 		log.Errorf("Failed to fetch statistics: %v", err)

go.mod

@@ -5,37 +5,20 @@ go 1.12
 replace github.com/Sirupsen/logrus => github.com/sirupsen/logrus v1.4.1
 
 require (
-	github.com/Sirupsen/logrus v0.0.0-00010101000000-000000000000 // indirect
-	github.com/aktau/github-release v0.7.2 // indirect
 	github.com/arangodb-helper/go-certificates v0.0.0-20180821055445-9fca24fc2680
 	github.com/arangodb/go-driver v0.0.0-20190430103524-b14f41496c3d
-	github.com/codegangsta/cli v1.20.0 // indirect
 	github.com/coreos/go-semver v0.3.0
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible
-	github.com/docker/docker v1.13.1 // indirect
-	github.com/docker/go-connections v0.4.0 // indirect
-	github.com/docker/go-metrics v0.0.0-20181218153428-b84716841b82 // indirect
-	github.com/docker/go-units v0.4.0 // indirect
-	github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 // indirect
-	github.com/dustin/go-humanize v1.0.0 // indirect
-	github.com/estesp/manifest-tool v0.9.0 // indirect
-	github.com/go-yaml/yaml v2.1.0+incompatible // indirect
-	github.com/gorilla/mux v1.7.1 // indirect
+	github.com/google/addlicense v0.0.0-20200906110928-a0294312aa76 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/mitchellh/gox v1.0.1 // indirect
-	github.com/opencontainers/go-digest v1.0.0-rc1 // indirect
-	github.com/opencontainers/image-spec v1.0.1 // indirect
-	github.com/opencontainers/runc v0.1.1 // indirect
-	github.com/opencontainers/runtime-spec v1.0.1 // indirect
 	github.com/pavel-v-chernykh/keystore-go v2.1.0+incompatible // indirect
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v0.9.2
 	github.com/prometheus/common v0.3.0
 	github.com/spf13/cobra v0.0.3
 	github.com/spf13/pflag v1.0.3 // indirect
-	github.com/tomnomnom/linkheader v0.0.0-20180905144013-02ca5825eb80 // indirect
-	github.com/vbatts/tar-split v0.11.1 // indirect
-	github.com/voxelbrain/goptions v0.0.0-20180630082107-58cddc247ea2 // indirect
-	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 // indirect
-	google.golang.org/grpc v1.20.1 // indirect
+	golang.org/x/sync v0.0.0-20201207232520-09787c993a3a // indirect
+	golang.org/x/sys v0.0.0-20201207223542-d4d67f95c62d // indirect
+	golang.org/x/tools v0.0.0-20201208233053-a543418bbed2 // indirect
 )