Prometheus overwrites log file when restarted

[jnogol]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Checked that your issue isn't already filled: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aidealista
  • Checked that there is not already provided the described functionality

Description

Due to the ">" in https://github.com/idealista/prometheus_server-role/blob/master/templates/prometheus.service.j2#L11, every time Prometheus is restarted it overwrites prometheus.log. It should be replaced with ">>" so it appends the new output to the previous log file.

Steps to Reproduce

1. Watch prometheus.log file.
2. Restart Prometheus with systemctl restart prometheus.service
3. Watch prometheus.log file.

Expected behavior: See both restarts.

Actual behavior: Only last restart appears.

Reproduces how often: Always

Versions

All.