Fluentd: add fluent-plugin-concat:1.0.0 gem
Fluentd: add fluent-plugin-concat:1.0.0 gem

Actual Fluentd config doesn't manage multiline log pattern like:

2017-08-16 21:41:03.097 7 WARNING oslo_config.cfg [req-34ea3f23-f780-4059-b911-2788ea4af7b2 - - - - -] Option "firewall_driver" from group "DEFAULT" is deprecated for removal (
nova-network is deprecated, as are any related configuration options.
). Its value may be silently ignored in the future.

This log will generate 1 Fluentd records for each line (3 records),
this is really a wrong behaviour, and made Kibana interface unusable.

This patch add fluent-plugin-concat in order to concatenate multiline
log separated in multiple events.

Change-Id: I83e583605b49b7c421109d662de1291f38bd5c07
Closes-Bug: #1711399

nihilifer/kolla,stackforge/kolla,rahulunair/kolla,stackforge/kolla,stackforge/kolla,nihilifer/kolla,openstack/kolla,openstack/kolla,rahulunair/kolla