Use keepalive for LDAP connections (#2344)

lemonldap-ng-common/lib/Lemonldap/NG/Common/Conf/Backends/LDAP.pm

@@ -91,8 +91,9 @@ sub ldap {
     # Connect
     my $ldap = Net::LDAP->new(
         \@servers,
-        onerror => undef,
-        verify  => ( $self->{ldapVerify} || "require" ),
+        keepalive => 1,
+        onerror   => undef,
+        verify    => ( $self->{ldapVerify} || "require" ),
         ( $self->{ldapCAFile} ? ( cafile => $self->{ldapCAFile} ) : () ),
         ( $self->{ldapCAPath} ? ( capath => $self->{ldapCAPath} ) : () ),
         ( $self->{ldapPort}   ? ( port   => $self->{ldapPort} )   : () ),

lemonldap-ng-common/lib/Lemonldap/NG/Common/Notifications/LDAP.pm

@@ -486,7 +486,8 @@ sub _ldap {
     # Connect
     my $ldap = Net::LDAP->new(
         \@servers,
-        onerror => undef,
+        onerror   => undef,
+        keepalive => 1,
         ( $self->ldapPort   ? ( port   => $self->ldapPort )   : () ),
         ( $self->ldapVerify ? ( verify => $self->ldapVerify ) : () ),
         ( $self->ldapCAFile ? ( cafile => $self->ldapCAFile ) : () ),

lemonldap-ng-portal/lib/Lemonldap/NG/Portal/Lib/Net/LDAP.pm

@@ -47,7 +47,8 @@ sub new {
     }
     $self = Net::LDAP->new(
         \@servers,
-        onerror => undef,
+        onerror   => undef,
+        keepalive => 1,
         ( $conf->{ldapPort}    ? ( port    => $conf->{ldapPort} )    : () ),
         ( $conf->{ldapTimeout} ? ( timeout => $conf->{ldapTimeout} ) : () ),
         ( $conf->{ldapVersion} ? ( version => $conf->{ldapVersion} ) : () ),
@@ -66,7 +67,7 @@ sub new {
         # socket when certificate validation fails. Net::LDAP does not catch
         # it, and the process ends up crashing.
         # As a precaution, make sure the underlying socket is doing fine:
-        if ( $self->socket->isa('IO::Socket::SSL')
+        if (    $self->socket->isa('IO::Socket::SSL')
             and $self->socket->errstr < 0 )
         {
             $portal->logger->error(