Title: Managing /etc/hosts on NixOS
       Author: Solène
       Date: 14 September 2021
       Tags: nixos
       Description: 
       
       # Introduction
       
       This is a simple article explaining how to manage entries in /etc/hosts
       in a NixOS system.  Modifying this file is quite useful when you need
       to make tests on a remote server while its domain name is still not
       updated so you can force a domain name to be resolved by a given IP
       address, bypassing DNS queries.
       
       NixOS being what is is, you can't modify the /etc/hosts file directly.
       
 (HTM) NixOS stable documentation about the extraHosts variable
       
       # Configuration
       
       In your /etc/nixos/configuration.nix file, you have to declare the
       variable networking.extraHosts and use "\n" as separator for entries.
       
       ```NixOS configuration file sample
       networking.extraHosts = "1.2.3.4 foobar.perso.pw\n1.2.3.5 foo.perso.pw";
       ```
       
       or as suggested by @tokudan@chaos.social on Mastodon, you can use
       multiple lines in the string as follow (using two single quotes
       character):
       
       ```NixOS configuration file sample
       networking.extraHosts = ''
       1.2.3.4 foobar.perso.pw
       1.2.3.5 foo.perso.pw
       '';
       ```
       
       The previous pieces of configuration will associate "foobar.perso.pw"
       to IP 1.2.3.4 and "foo.perso.pw" to IP 1.2.3.5.
       
       Now, I need to rebuild my system configuration and use it, this can be
       done with the command `nixos-rebuild switch` as root.