BUGFIX : conLdap now global (was previously recreated at each request after a failure, exhausting LDAP server connections)

mxrouter.go

@@ -1,7 +1,6 @@
 // mxrouter
 // Copyright (c) 2020 yo000 <johan@nosd.in>
 //
-// TODO : REconnexion ldap lorsque necessaire
 
 // checkmx : postfix tcp_table server which returns second-level domain name of the MX of a domain
 // ex :
@@ -27,11 +26,12 @@ import (
 )
 
 const (
-	version = "0.9.4"
+	version = "0.9.5"
 )
 
 var (
 	logstream  *syslog.Writer
+	conLdap    *ldap.Conn
 	mutex      sync.Mutex
 	debug      *bool
 	listen     *string
@@ -43,20 +43,22 @@ var (
 	defDomain  *string
 )
 
-func ldapSearch(conLdap *ldap.Conn, searchReq *ldap.SearchRequest, attempt int) (*ldap.SearchResult, error) {
+func ldapSearch(searchReq *ldap.SearchRequest, attempt int) (*ldap.SearchResult, error) {
 	mutex.Lock()
 	result, err := conLdap.Search(searchReq)
 	mutex.Unlock()
 	// Let's just manage connection errors here
 	if err != nil && strings.HasSuffix(err.Error(), "ldap: connection closed") {
 		logstream.Err("LDAP connection closed, retrying")
+		mutex.Lock()
 		conLdap.Close()
 		conLdap, err = connectLdap()
+		mutex.Unlock()
 		if err != nil {
 			return result, err
 		} else {
 			attempt = attempt + 1
-			return ldapSearch(conLdap, searchReq, attempt)
+			return ldapSearch(searchReq, attempt)
 		}
 	}
 
@@ -109,7 +111,7 @@ func handleConnection(connClt net.Conn, conLdap *ldap.Conn) {
 		searchReq := ldap.NewSearchRequest(*ldapBaseDN, ldap.ScopeWholeSubtree, 0, 0, 0,
 			false, filter, []string{*ldapAttr}, []ldap.Control{})
 
-		result, err := ldapSearch(conLdap, searchReq, 0)
+		result, err := ldapSearch(searchReq, 0)
 		if err != nil {
 			logstream.Err(fmt.Sprintln("Error searching into LDAP: ", err))
 			s := strings.Replace(err.Error(), " ", "%20", -1)
@@ -159,7 +161,9 @@ func handleConnection(connClt net.Conn, conLdap *ldap.Conn) {
 }
 
 func connectLdap() (*ldap.Conn, error) {
-	conLdap, err := ldap.DialURL(*ldapURL)
+	var err error
+
+	conLdap, err = ldap.DialURL(*ldapURL)
 	if err != nil {
 		logstream.Err(fmt.Sprintln("Error dialing LDAP: ", err))
 		return conLdap, err