Merge pull request karrieretutor#1 from karrieretutor/fix-external-disco

added tcp conn watcher

CHANGELOG.md

@@ -0,0 +1,13 @@
+# Changelog
+## Unreleased
+
+## [0.0.2] 2019-09-05
+### Added
+- the prom exporter now watches the tcp conn to the xmpp server (this led to some confusion on k8s), if the connection to the xmpp server is lost, the exporter exits 
+
+### Fixed
+- Exit the prom-exporter if connection gets closed externally (eg. the XMPP server stops)
+
+## [0.0.1] 2019-08-30
+### Added
+- initial release

exporter/main.go

@@ -21,6 +21,7 @@ import (
 	"crypto/tls"
 	"encoding/xml"
 	"fmt"
+	"net"
 	"net/http"
 	"os"
 	"os/signal"
@@ -53,6 +54,8 @@ var (
 		connected: false,
 	}
 
+	serverChecker *xmpp.ServerCheck
+
 	jvbbrewery string
 	cm         *xmpp.StreamManager
 
@@ -120,6 +123,20 @@ func main() {
 		fmt.Println("internal muc domain not specified")
 		os.Exit(2)
 	}
+
+	//we need a serverchecker
+	go func() {
+		address := xmppServer + ":" + xmppPort
+		for true {
+			_, err := net.DialTimeout("tcp", address, 5*time.Second)
+			if err != nil {
+				fmt.Printf("Could not connect to server %s: %s\nexiting\n", address, err.Error())
+				signals <- iExit
+			}
+			time.Sleep(10 * time.Second)
+		}
+	}()
+
 	jvbbrewery = breweryroom + "@" + internalMucDomain
 
 	jid := xmppUser + "@" + xmppAuthDomain
@@ -169,7 +186,8 @@ func main() {
 }
 
 func shutdown() {
-	if cm != nil {
+	//we get a segfault if connection actually never happened
+	if cm != nil && cm.Metrics.ConnectTime != 0*time.Second {
 		cm.Stop()
 	}
 }
@@ -251,5 +269,11 @@ func connectClient(c xmpp.Config, r *xmpp.Router) {
 	if err != nil {
 		fmt.Printf("xmpp connection manager returned with error: %s\n", err.Error())
 		signals <- iFail
+		return
 	}
+
+	//connection closed we are done
+	fmt.Println("XMPP connection closed, exiting.")
+	signals <- iExit
+	return
 }