Rotate nginx logs (#601)

* Rotate nginx logs

* Create logrotate.sh

* Update Dockerfile

* Update entrypoint.sh

* Update Dockerfile

* Update logrotate.sh

* No reason to disable logrotate

* Update logrotate.sh

* Update entrypoint.sh

* typo

* Avoid useless output

* Use gosu

util/Nginx/logrotate.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+while true
+do
+  [ "$1" == "loop" ] && sleep $((24 * 3600 - (`date +%H` * 3600 + `date +%M` * 60 + `date +%S`)))
+  ts=$(date +%Y%m%d_%H%M%S)
+  mv /var/log/nginx/access.log /var/log/nginx/access.$ts.log
+  mv /var/log/nginx/error.log /var/log/nginx/error.$ts.log
+  kill -USR1 `cat /var/run/nginx/nginx.pid`
+  sleep 1
+  gzip /var/log/nginx/access.$ts.log
+  gzip /var/log/nginx/error.$ts.log
+  find /var/log/nginx/ -name "*.gz" -mtime +32 -delete
+  [ "$1" != "loop" ] && break
+done