Merge pull request #7 from wbollock/feat/https_support

feat!: https and timeout support

README.md

@@ -41,7 +41,13 @@ Create a simple `config.toml` in `/etc/prometheus-nagios-exporter` with your Nag
 APIKey = ""
 ```
 
-By default this will point to localhost, but a remote address can be specified with `--web.remote-address`. The default port is `9111`, but can be changed with `--web.listen-address`.
+By default this will point to `http://localhost`, but a remote address can be specified with `--nagios.scrape-uri`. The default port is `9111`, but can be changed with `--web.listen-address`.
+
+SSL support is included for scraping remote Nagios endpoints, and SSL verification can be enabled/disabled with `--nagios.ssl-verify`. A scrape timeout value is also available with `--nagios.timeout`.
+
+```bash
+./nagios_exporter --nagios.scrape-uri https://<my-tls-url> --nagios.ssl-verify true --nagios.timeout 5
+```
 
 To see all available configuration flags:
 

nagios_exporter.go

@@ -1,10 +1,12 @@
 package main
 
 import (
+	"crypto/tls"
 	"encoding/json"
 	"flag"
 	"io"
 	"net/http"
+	"time"
 
 	"github.com/BurntSushi/toml"
 	"github.com/prometheus/client_golang/prometheus"
@@ -153,12 +155,16 @@ var (
 
 type Exporter struct {
 	nagiosEndpoint, nagiosAPIKey string
+	sslVerify                    bool
+	nagiosAPITimeout             time.Duration
 }
 
-func NewExporter(nagiosEndpoint, nagiosAPIKey string) *Exporter {
+func NewExporter(nagiosEndpoint, nagiosAPIKey string, sslVerify bool, nagiosAPITimeout time.Duration) *Exporter {
 	return &Exporter{
-		nagiosEndpoint: nagiosEndpoint,
-		nagiosAPIKey:   nagiosAPIKey,
+		nagiosEndpoint:   nagiosEndpoint,
+		nagiosAPIKey:     nagiosAPIKey,
+		sslVerify:        sslVerify,
+		nagiosAPITimeout: nagiosAPITimeout,
 	}
 }
 
@@ -186,11 +192,11 @@ func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
 	ch <- servicechecksPerformance
 }
 
-func (e *Exporter) TestNagiosConnectivity() float64 {
+func (e *Exporter) TestNagiosConnectivity(sslVerify bool, nagiosAPITimeout time.Duration) float64 {
 
 	systemStatusURL := e.nagiosEndpoint + systemstatusAPI + "?apikey=" + e.nagiosAPIKey
 
-	body := QueryAPIs(systemStatusURL)
+	body := QueryAPIs(systemStatusURL, sslVerify, nagiosAPITimeout)
 	log.Debug("Queried API: ", systemstatusAPI)
 
 	systemStatusObject := systemStatus{}
@@ -205,7 +211,7 @@ func (e *Exporter) TestNagiosConnectivity() float64 {
 
 func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 
-	nagiosStatus := e.TestNagiosConnectivity()
+	nagiosStatus := e.TestNagiosConnectivity(e.sslVerify, e.nagiosAPITimeout)
 
 	if nagiosStatus == 0 {
 		log.Warn("Cannot connect to Nagios endpoint")
@@ -215,11 +221,20 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 		up, prometheus.GaugeValue, nagiosStatus,
 	)
 
-	e.QueryAPIsAndUpdateMetrics(ch)
+	e.QueryAPIsAndUpdateMetrics(ch, e.sslVerify, e.nagiosAPITimeout)
 
 }
 
-func QueryAPIs(url string) (body []byte) {
+func QueryAPIs(url string, sslVerify bool, nagiosAPITimeout time.Duration) (body []byte) {
+
+	// https://github.com/prometheus/haproxy_exporter/blob/main/haproxy_exporter.go#L337-L345
+
+	tr := &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: !sslVerify}}
+
+	client := http.Client{
+		Timeout:   nagiosAPITimeout,
+		Transport: tr,
+	}
 
 	req, err := http.NewRequest("GET", url, nil)
 
@@ -230,16 +245,16 @@ func QueryAPIs(url string) (body []byte) {
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("User-Agent", "Prometheus")
 
-	resp, err := http.DefaultClient.Do(req)
+	resp, err := client.Do(req)
 
 	if err != nil {
-		log.Warn(err)
+		log.Fatal(err)
 	}
 
 	if resp.Body != nil {
 		defer resp.Body.Close()
 	} else {
-		log.Warn("HTTP response body is nil - check API connectivity")
+		log.Fatal("HTTP response body is nil - check API connectivity")
 	}
 
 	body, readErr := io.ReadAll(resp.Body)
@@ -251,13 +266,13 @@ func QueryAPIs(url string) (body []byte) {
 	return body
 }
 
-func (e *Exporter) QueryAPIsAndUpdateMetrics(ch chan<- prometheus.Metric) {
+func (e *Exporter) QueryAPIsAndUpdateMetrics(ch chan<- prometheus.Metric, sslVerify bool, nagiosAPITimeout time.Duration) {
 
 	// get system status
 	systeminfoURL := e.nagiosEndpoint + systeminfoAPI + "?apikey=" + e.nagiosAPIKey
 	log.Debug("Queried API: ", systeminfoAPI)
 
-	body := QueryAPIs(systeminfoURL)
+	body := QueryAPIs(systeminfoURL, sslVerify, nagiosAPITimeout)
 
 	systemInfoObject := systemInfo{}
 	jsonErr := json.Unmarshal(body, &systemInfoObject)
@@ -272,7 +287,7 @@ func (e *Exporter) QueryAPIsAndUpdateMetrics(ch chan<- prometheus.Metric) {
 	// host status
 	hoststatusURL := e.nagiosEndpoint + hoststatusAPI + "?apikey=" + e.nagiosAPIKey
 
-	body = QueryAPIs(hoststatusURL)
+	body = QueryAPIs(hoststatusURL, sslVerify, nagiosAPITimeout)
 	log.Debug("Queried API: ", systeminfoAPI)
 
 	hostStatusObject := hostStatus{}
@@ -357,7 +372,7 @@ func (e *Exporter) QueryAPIsAndUpdateMetrics(ch chan<- prometheus.Metric) {
 	// service status
 	servicestatusURL := e.nagiosEndpoint + servicestatusAPI + "?apikey=" + e.nagiosAPIKey
 
-	body = QueryAPIs(servicestatusURL)
+	body = QueryAPIs(servicestatusURL, sslVerify, nagiosAPITimeout)
 	log.Debug("Queried API: ", servicestatusAPI)
 
 	serviceStatusObject := serviceStatus{}
@@ -459,7 +474,7 @@ func (e *Exporter) QueryAPIsAndUpdateMetrics(ch chan<- prometheus.Metric) {
 	// service status
 	systemStatusDetailURL := e.nagiosEndpoint + systemstatusDetailAPI + "?apikey=" + e.nagiosAPIKey
 
-	body = QueryAPIs(systemStatusDetailURL)
+	body = QueryAPIs(systemStatusDetailURL, sslVerify, nagiosAPITimeout)
 	log.Debug("Queried API: ", systemstatusDetailAPI)
 
 	systemStatusDetailObject := systemStatusDetail{}
@@ -573,8 +588,13 @@ func main() {
 			"Address to listen on for telemetry")
 		metricsPath = flag.String("web.telemetry-path", "/metrics",
 			"Path under which to expose metrics")
-		remoteAddress = flag.String("web.remote-address", "localhost",
+		remoteAddress = flag.String("nagios.scrape-uri", "http://localhost",
 			"Nagios application address")
+		sslVerify = flag.Bool("nagios.ssl-verify", false,
+			"SSL certificate validation")
+		// I think users would rather enter `5` over `5s`, e.g int vs Duration flag
+		nagiosAPITimeout = flag.Int("nagios.timeout", 5,
+			"Timeout for querying Nagios API in seconds")
 		configPath = flag.String("config.path", "/etc/prometheus-nagios-exporter/config.toml",
 			"Config file path")
 		logLevel = flag.String("log.level", "info",
@@ -592,10 +612,10 @@ func main() {
 
 	var conf Config = ReadConfig(*configPath)
 
-	// TODO - HTTPS support
-	nagiosURL := "http://" + *remoteAddress + nagiosAPIVersion + apiSlug
+	nagiosURL := *remoteAddress + nagiosAPIVersion + apiSlug
 
-	exporter := NewExporter(nagiosURL, conf.APIKey)
+	// convert timeout flag to seconds
+	exporter := NewExporter(nagiosURL, conf.APIKey, *sslVerify, time.Duration(*nagiosAPITimeout)*time.Second)
 	prometheus.MustRegister(exporter)
 
 	log.Info("Using connection endpoint: ", *remoteAddress)

nfpm/etc/default/prometheus-nagios-exporter

@@ -1,2 +1,2 @@
 # Prometheus Nagios Exporter default arguments
-ARGS="-config.path /etc/prometheus-nagios-exporter/config.toml -web.remote-address localhost"
+ARGS="--config.path /etc/prometheus-nagios-exporter/config.toml --nagios.scrape-uri http://localhost"