From 5c6fe8580c20e1fed13b14b3533eff84c037d3e2 Mon Sep 17 00:00:00 2001
From: spleenftw <57947900+Spleenftw@users.noreply.github.com>
Date: Fri, 23 Feb 2024 00:27:05 +0100
Subject: [PATCH] Update main.go

Adding a new metric  :service_openvpn
---
 main.go | 131 +++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 82 insertions(+), 49 deletions(-)

diff --git a/main.go b/main.go
index 07a6fe0..d8c5326 100644
--- a/main.go
+++ b/main.go
@@ -1,59 +1,92 @@
-// Copyright 2017 Kumina, https://kumina.nl/
-// 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.
-
 package main
 
 import (
-	"flag"
-	"github.com/kumina/openvpn_exporter/exporters"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"log"
-	"net/http"
-	"strings"
+//      "bytes"
+        "flag"
+        "fmt"
+        "github.com/kumina/openvpn_exporter/exporters"
+        "github.com/prometheus/client_golang/prometheus"
+        "github.com/prometheus/client_golang/prometheus/promhttp"
+        "log"
+        "net/http"
+        "os/exec"
+        "strings"
+        "time"
 )
 
+var serviceOpenVPN = prometheus.NewGauge(prometheus.GaugeOpts{
+        Name: "service_openvpn",
+        Help: "Indicates whether the OpenVPN service is up (1) or down (0).",
+})
+
 func main() {
-	var (
-		listenAddress      = flag.String("web.listen-address", ":9176", "Address to listen on for web interface and telemetry.")
-		metricsPath        = flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics.")
-		openvpnStatusPaths = flag.String("openvpn.status_paths", "examples/client.status,examples/server2.status,examples/server3.status", "Paths at which OpenVPN places its status files.")
-		ignoreIndividuals  = flag.Bool("ignore.individuals", false, "If ignoring metrics for individuals")
-	)
-	flag.Parse()
+        var (
+                listenAddress      = flag.String("web.listen-address", ":9176", "Address to listen on for web interface and telemetry.")
+                metricsPath        = flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics.")
+                openvpnStatusPaths = flag.String("openvpn.status_paths", "/var/log/openvpn-status.log", "Paths at which OpenVPN places its status files.")
+                ignoreIndividuals  = flag.Bool("ignore.individuals", false, "If ignoring metrics for individuals.")
+        )
+        flag.Parse()
 
-	log.Printf("Starting OpenVPN Exporter\n")
-	log.Printf("Listen address: %v\n", *listenAddress)
-	log.Printf("Metrics path: %v\n", *metricsPath)
-	log.Printf("openvpn.status_path: %v\n", *openvpnStatusPaths)
-	log.Printf("Ignore Individuals: %v\n", *ignoreIndividuals)
+        log.Printf("Starting OpenVPN Exporter\n")
+        log.Printf("Listen address: %v\n", *listenAddress)
+        log.Printf("Metrics path: %v\n", *metricsPath)
+        log.Printf("openvpn.status_path: %v\n", *openvpnStatusPaths)
+        log.Printf("Ignore Individuals: %v\n", *ignoreIndividuals)
 
-	exporter, err := exporters.NewOpenVPNExporter(strings.Split(*openvpnStatusPaths, ","), *ignoreIndividuals)
-	if err != nil {
-		panic(err)
-	}
-	prometheus.MustRegister(exporter)
+        exporter, err := exporters.NewOpenVPNExporter(strings.Split(*openvpnStatusPaths, ","), *ignoreIndividuals)
+        if err != nil {
+                panic(err)
+        }
+        prometheus.MustRegister(exporter)
+        prometheus.MustRegister(serviceOpenVPN)
 
-	http.Handle(*metricsPath, promhttp.Handler())
-	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		w.Write([]byte(`
-			<html>
-			<head><title>OpenVPN Exporter</title></head>
-			<body>
-			<h1>OpenVPN Exporter</h1>
-			<p><a href='` + *metricsPath + `'>Metrics</a></p>
-			</body>
-			</html>`))
-	})
-	log.Fatal(http.ListenAndServe(*listenAddress, nil))
+        go updateOpenVPNServiceStatus()
+
+        http.Handle(*metricsPath, promhttp.Handler())
+        http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+                w.Write([]byte(`
+                        <html>
+                        <head><title>OpenVPN Exporter</title></head>
+                        <body>
+                        <h1>OpenVPN Exporter</h1>
+                        <p><a href='` + *metricsPath + `'>Metrics</a></p>
+                        </body>
+                        </html>`))
+        })
+        log.Fatal(http.ListenAndServe(*listenAddress, nil))
+}
+
+func updateOpenVPNServiceStatus() {
+        for {
+                isActive, err := isServiceActive("openvpn")
+                if err != nil {
+                        log.Printf("Error checking OpenVPN service status: %v", err)
+                } else {
+                        if isActive {
+                                serviceOpenVPN.Set(1)
+                        } else {
+                                serviceOpenVPN.Set(0)
+                        }
+                }
+                time.Sleep(5 * time.Second)
+        }
+}
+
+func isServiceActive(serviceName string) (bool, error) {
+    cmd := exec.Command("systemctl", "is-active", "--quiet", serviceName)
+
+    // Run the command without capturing output
+    if err := cmd.Run(); err != nil {
+        // Check if exit status is 3 (unknown) and treat it as inactive
+        if exitError, ok := err.(*exec.ExitError); ok {
+            if status, ok := exitError.Sys().(syscall.WaitStatus); ok && status.ExitStatus() == 3 {
+                return false, nil
+            }
+        }
+
+        return false, fmt.Errorf("failed to check service status: %v", err)
+    }
+
+    return true, nil
 }