Create an initial configuration

This is a NixOS system definition for a minimal working system with only
an SSH server.

.gitignore

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+hardware-configuration.nix

README.md

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+Configuration for my VPS
+========================
+
+This is the configuration for my virtual private server on
+[OVH](https://www.ovh.com/). The system is managed using
+[NixOS](https://nixos.org/).
+
+From Debian to NixOS
+--------------------
+
+Out of the box, the server came with a Debian 10 installation, OVH does not
+offer NixOS as an option for their servers. The part of the dicumentation on
+[Installing from another Linux
+distribution](https://nixos.org/nixos/manual/index.html#sec-installing-from-other-distro)
+on the same partition did work fine.  The call to `nixos-generate-config` made
+an initial configuration with `extlinux` as the boot loader but the VPS
+actually uses Grub.

configuration.nix

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+# The is the system definition for vps749417.ovh.net.
+
+{ config, pkgs, ... }:
+
+{
+  imports =
+    [ # Include the results of the hardware scan.
+      ./hardware-configuration.nix
+    ];
+
+  # Boot loader
+  boot.loader = {
+    grub = {
+      enable = true;
+      device = "/dev/sda";
+    };
+  };
+
+  # Network configuration
+  networking = {
+    hostName = "vps749417";
+    useDHCP = false;
+    interfaces.ens3.useDHCP = true;
+  };
+
+  # Time zone
+  time.timeZone = "Europe/Paris";
+
+  # Packages installed in system profile
+  environment.systemPackages = with pkgs; [
+    git htop tmux vim wget
+  ];
+
+  # OpenSSH daemon
+  services.openssh = {
+    enable = true;
+    passwordAuthentication = false;
+  };
+
+  # Initial user account
+  users.users.manu = {
+    isNormalUser = true;
+    extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
+    initialHashedPassword = "$6$40/yq55oyhD2MhbS$fox2DB5Aj4EpbQAx8z6FYEh3Jl3HKa7aHlGbijJukWxOpXIlKqNucBA8Eene7SaUQzHpvrhke9EFZIRxZpl5F/";
+  };
+
+  # This value determines the NixOS release with which your system is to be
+  # compatible, in order to avoid breaking some software such as database
+  # servers. You should change this only after NixOS release notes say you
+  # should.
+  system.stateVersion = "19.09"; # Did you read the comment?
+
+}
+