From 8e0284d9f04fa885c67493a5af2db6df6fb291db Mon Sep 17 00:00:00 2001
From: Hector <hector@hjs.dev>
Date: Thu, 22 Jun 2023 15:16:12 +0000
Subject: [PATCH] feat: print fail2ban version on startup (!96)

* Print the version reported by `fail2ban-server` when the exporter starts up
* Logs an error if the connection to the server fails

https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/-/merge_requests/96
---
 collector/f2b/collector.go | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/collector/f2b/collector.go b/collector/f2b/collector.go
index 95f9bd0..e6a8ed8 100644
--- a/collector/f2b/collector.go
+++ b/collector/f2b/collector.go
@@ -1,11 +1,12 @@
 package f2b
 
 import (
+	"log"
+	"os"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/cfg"
 	"gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/socket"
-	"log"
-	"os"
 )
 
 type Collector struct {
@@ -18,7 +19,8 @@ type Collector struct {
 }
 
 func NewExporter(appSettings *cfg.AppSettings, exporterVersion string) *Collector {
-	log.Printf("reading metrics from fail2ban socket: %s", appSettings.Fail2BanSocketPath)
+	log.Printf("reading fail2ban metrics from socket file: %s", appSettings.Fail2BanSocketPath)
+	printFail2BanServerVersion(appSettings.Fail2BanSocketPath)
 	return &Collector{
 		socketPath:                 appSettings.Fail2BanSocketPath,
 		exporterVersion:            exporterVersion,
@@ -58,3 +60,17 @@ func (c *Collector) Collect(ch chan<- prometheus.Metric) {
 	}
 	c.collectErrorCountMetric(ch)
 }
+
+func printFail2BanServerVersion(socketPath string) {
+	s, err := socket.ConnectToSocket(socketPath)
+	if err != nil {
+		log.Printf("error connecting to socket: %v", err)
+	} else {
+		version, err := s.GetServerVersion()
+		if err != nil {
+			log.Printf("error interacting with socket: %v", err)
+		} else {
+			log.Printf("successfully connected to fail2ban socket! fail2ban version: %s", version)
+		}
+	}
+}