Revert "removed .json on logfile name"

This reverts commit 866dfba61954546e70665ced7d69f5dc7984e55c.
in orbit of rotatelog, logstash
changed nginx log directory /var to /mnt
Revert "changed nginx log directory /var to /mnt"

This reverts commit 67ed5e7de36e84dd7c6a45a16a6ecbb4a2101a9b.
elasticsearch to EBS volume