added ca file and option skipverify

will close #14

README.md

@@ -32,6 +32,8 @@ Settings:
 * PUBLISH_PORT:    "9090",
 * OUTPUT_FORMAT:   "TTY", //change to JSON if needed
 * LOG_LEVEL:       "info", // can be "debug", "info", "warning", "error", "fatal", or "panic"
+* CAFILE:          "ca.pem", // default is ca.pem. If file does not exist it will be ignored.
+* SKIPVERIFY:      false or 0, true or 1 // will skip hostname/certificate check at all
 
 Example
 

config.go

@@ -10,20 +10,24 @@ import (
 var (
 	config        rabbitExporterConfig
 	defaultConfig = rabbitExporterConfig{
-		RabbitURL:      "http://localhost:15672",
-		RabbitUsername: "guest",
-		RabbitPassword: "guest",
-		PublishPort:    "9090",
-		OutputFormat:   "TTY", //JSON
+		RabbitURL:          "http://localhost:15672",
+		RabbitUsername:     "guest",
+		RabbitPassword:     "guest",
+		PublishPort:        "9090",
+		OutputFormat:       "TTY", //JSON
+		CAFile:             "ca.pem",
+		InsecureSkipVerify: false,
 	}
 )
 
 type rabbitExporterConfig struct {
-	RabbitURL      string
-	RabbitUsername string
-	RabbitPassword string
-	PublishPort    string
-	OutputFormat   string
+	RabbitURL          string
+	RabbitUsername     string
+	RabbitPassword     string
+	PublishPort        string
+	OutputFormat       string
+	CAFile             string
+	InsecureSkipVerify bool
 }
 
 func initConfig() {
@@ -52,4 +56,11 @@ func initConfig() {
 	if output := os.Getenv("OUTPUT_FORMAT"); output != "" {
 		config.OutputFormat = output
 	}
+
+	if cafile := os.Getenv("CAFILE"); cafile != "" {
+		config.CAFile = cafile
+	}
+	if insecureSkipVerify := os.Getenv("SKIPVERIFY"); insecureSkipVerify == "true" || insecureSkipVerify == "1" {
+		config.InsecureSkipVerify = true
+	}
 }

main.go

@@ -24,6 +24,7 @@ func initLogger() {
 func main() {
 	initConfig()
 	initLogger()
+	InitClient()
 	exporter := newExporter()
 	prometheus.MustRegister(exporter)
 

rabbitClient.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"bytes"
+	"crypto/tls"
+	"crypto/x509"
 	"encoding/json"
 	"errors"
 	"io/ioutil"
@@ -13,6 +15,31 @@ import (
 
 var client = &http.Client{Timeout: 10 * time.Second}
 
+func InitClient() {
+	roots := x509.NewCertPool()
+
+	if data, err := ioutil.ReadFile(config.CAFile); err == nil {
+		if !roots.AppendCertsFromPEM(data) {
+			log.WithField("filename", config.CAFile).Error("Adding certificate to rootCAs failed")
+		}
+	} else {
+		log.Info("Using default certificate pool")
+	}
+
+	tr := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			InsecureSkipVerify: config.InsecureSkipVerify,
+			RootCAs:            roots,
+		},
+	}
+
+	client = &http.Client{
+		Transport: tr,
+		Timeout:   10 * time.Second,
+	}
+
+}
+
 func loadMetrics(config rabbitExporterConfig, endpoint string) (*json.Decoder, error) {
 	req, err := http.NewRequest("GET", config.RabbitURL+"/api/"+endpoint, nil)
 	req.SetBasicAuth(config.RabbitUsername, config.RabbitPassword)