Satisfy golint (#3)

Makefile

@@ -17,9 +17,8 @@ LDFLAGS = -ldflags "-X main.VERSION=${VERSION} -X main.COMMIT=${COMMIT} -X main.
 # Build the project
 all: build
 
-test:
-	cd ${BUILD_DIR}; \
-	go test ${PKG_LIST}; \
+dep:
+	go get -v -d ./cmd/prometheus-cert-exporter/... ;
 
 fmt:
 	cd ${BUILD_DIR}; \
@@ -49,8 +48,11 @@ misspell:
 	cd ${BUILD_DIR}; \
 	find . -type f -not -path "./vendor/*" -not -path "./.git/*" -print0 | xargs -0 ${GOPATH}/bin/misspell; \
 
-dep:
-	go get -v -d ./cmd/prometheus-cert-exporter/... ;
+ci: fmt vet gocyclo golint ineffassign misspell 
+
+test: dep
+	cd ${BUILD_DIR}; \
+	go test ${PKG_LIST}; \
 
 linux: dep
 	CGO_ENABLED=0 GOOS=linux GOARCH=${GOARCH} go build ${LDFLAGS} -o ${BUILD_DIR}/out/${BINARY}-linux-${GOARCH} cmd/prometheus-cert-exporter/main.go
@@ -64,20 +66,7 @@ darwin: dep
 windows: dep
 	CGO_ENABLED=0 GOOS=windows GOARCH=${GOARCH} go build ${LDFLAGS} -o ${BUILD_DIR}/out/${BINARY}-windows-${GOARCH}.exe cmd/prometheus-cert-exporter/main.go
 
-docker_build:
-	docker run --rm -v "${PWD}":/go/src/github.com/amimof/prometheus-cert-exporter -w /go/src/github.com/amimof/prometheus-cert-exporter golang:${GOVERSION} make fmt test
-	docker build -t amimof/prometheus-cert-exporter:${VERSION} .
-	docker tag amimof/prometheus-cert-exporter:${VERSION} amimof/prometheus-cert-exporter:latest
-
-docker_push:
-	docker push amimof/prometheus-cert-exporter:${VERSION}
-	docker push amimof/prometheus-cert-exporter:latest
-
-docker: docker_build docker_push
-
 build: linux darwin rpi windows
 
 clean:
-	-rm -rf ${BUILD_DIR}/out/
-
-.PHONY: linux darwin windows test fmt clean
+	rm -rf ${BUILD_DIR}/out/

cmd/prometheus-cert-exporter/main.go

@@ -12,12 +12,19 @@ import (
 	"net/http"
 )
 
-var (
-	VERSION   string
-	COMMIT    string
-	BRANCH    string
-	GOVERSION string
+// VERSION is generated during compile as is never to be set here
+var VERSION string
+
+// COMMIT is the Git commit hash and is generated during compile as is never to be set here
+var COMMIT string
+
+// BRANCH is the Git branch name and is generated during compile as is never to be set here
+var BRANCH string
 
+// GOVERSION is the Go version used to compile and is generated during compile as is never to be set here
+var GOVERSION string
+
+var (
 	host   string
 	port   int
 	listen string

pkg/exporter/exporter.go

@@ -12,7 +12,7 @@ import (
 	"sync"
 )
 
-var extensions []string = []string{".pem", "crt", "cert", "cer"}
+var extensions = []string{".pem", "crt", "cert", "cer"}
 
 func findCertPaths(p string) ([]string, error) {
 	paths := []string{}
@@ -40,26 +40,34 @@ func isCertFile(p string) bool {
 	return false
 }
 
+// Exporter implements prometheus.Collector interface
 type Exporter struct {
 	mux        sync.Mutex
 	roots      []string
 	certExpiry *prometheus.GaugeVec
 }
 
+// SetRoots sets the list of file paths that the exporter should search for certificates in
 func (e *Exporter) SetRoots(p []string) {
 	e.roots = p
 }
 
+// Collect satisfies prometheus.Collector interface
 func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 	e.mux.Lock()
 	defer e.mux.Unlock()
 	e.Scrape(ch)
 }
 
+// Describe satisfies prometheus.Collector interface
 func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
 	ch <- e.certExpiry.WithLabelValues("path", "issuer", "alg", "version", "subject", "dns_names", "email_addresses").Desc()
 }
 
+// Scrape iterates over the list of file paths (set by SetRoot) and parses any found x509 certificates.
+// Certificates are parsed and the fields are mapped to prometheus labels which attached to a Gauge.
+// Scrape will create a new time series for each certificate file with its associated labels. The value
+// of the series equals the expiry of the certificate in UNIX timestamp.
 func (e *Exporter) Scrape(ch chan<- prometheus.Metric) {
 	for _, root := range e.roots {
 		paths, err := findCertPaths(root)
@@ -103,6 +111,7 @@ func (e *Exporter) Scrape(ch chan<- prometheus.Metric) {
 
 }
 
+// New creates an instance of Exporter and returns it
 func New() *Exporter {
 	return &Exporter{
 		certExpiry: prometheus.NewGaugeVec(prometheus.GaugeOpts{