Create few good practices for our infrastucture

[CharlesNepote]

I created this page as a start: https://github.com/openfoodfacts/openfoodfacts-infrastructure/wiki

Everything can be discussed.

Here are some practices we could talk about:

0. Few and simple rules have a better chance to be followed.
   We could prioritise as W3C use to, with keywords “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL”.

1. Disable password authentication in favour of SSH keys
   Using SSH key IS really simpler, I can write a quick documentation for beginners.

2. Disable root login over SSH

3. Working with root or not

4. Taking care of production resources: always using "nice" for scripts manually launched
   Stéphane's tip: just use nice ./mycommand -arg1 foo -arg2 bar (nice default to lower the priority).

5. When possible, use techs that the majority of people knows
   Our infrastructure is not so big. Low techs ensure it will be maintainable.
   Example: good old scripts vs Ansible.

6. Standardize some core tools
   Example: our standard distro is Linux Debian (well suited with point 5).

7. Basic tools to install on each machine
   Example: htop, goaccess...

8. Log every sys action on /root/changelog.log

9. Add important commands beeing played to /root/changelog.log
   So everybody knows what you have done concretly.

10. Backups?

11. Monitoring?