5.5 KiB
Setup
Add this repo to your local Nix registry
As an alternative to a local checkout, always pull the latest code from this repo.
nix registry add c3d2 git+https://gitea.c3d2.de/C3D2/nix-config
This enables nix
commands to find this Flake given the c3d2#
prefix in some arguments.
Working with this repo
If you checked out this git repository for working on the code,
replace c3d2#
with .#
and run commands from the repository root.
Don't forget to git add
new files! Flakes require that.
The secrets repo
Make sure you have access.
Install Nix Flakes
Nix Flakes ist gegenwärtig bei Nix (Version 20.09) noch keine standardmäßige Funktionalität für Nix. Die Bereitstellung der Kommandos für Nix Flakes müssen als experimentelle Funktionalität für das Kommando ''nix'' festgelegt werden, um sie verfügbar zu machen.
Set some configuration (do this only once):
echo 'experimental-features = nix-command flakes' >> ~/.config/nix/nix.conf
Permanent System with Nix Flakes
set this to your NixOS configuration:
{ pkgs, ... }: {
nix = {
extraOptions = "experimental-features = nix-command flakes";
};
}
Deployment
Deploy a NixOS system from this Flake locally
Running nixos-rebuild --flake c3d2 switch
on a machine should be sufficient
to update that machine to the current configuration and Nixpkgs revision.
Deploy to a remote NixOS system with this Flake
For every host that has a nixosConfiguration
in our Flake, there are
two scripts that can be run for deployment via ssh.
-
nix run .#glotzbert-nixos-rebuild switch
Copies the current state to build on the target system. This may fail due to eg. container resource limits.
The target must already be a nixFlakes system.
-
nix run .#glotzbert-nixos-rebuild-local switch
Builds locally, then uses
nix copy
to transfer the new NixOS system to the target.Help! It's needlessly rebuilding stuff that already runs on the target? If so, use
nix copy
to transfer where/run/current-system
points to to your build machine.
Remote deployment from non-NixOS
A shell script that copies the current working tree, and runs
nixos-rebuild switch
on the target:
./deploy-flake.sh hydra.hq.c3d2.de
It cannot not lookup hostnames in host-registry.nix
. To avoid
deploying the wrong container on the unrelated DNS records, the script
always uses the hostname that is already configured on the target
system.
Checking for updates
nix run .#list-upgradable
Checks all hosts with a nixosConfiguration
in flake.nix
.
Update from Hydra build
The fastest way to update a system, a manual alternative to setting
c3d2.autoUpdate = true;
Just run:
update-from-hydra
Deploy a MicroVM
Building spaceapi remotely, and deploy
nix run .#microvm-update-spaceapi
Building spaceapi locally, and deploy
nix run .#microvm-update-spaceapi-local
Update MicroVM from our Hydra
Our Hydra runs nix flake update
daily in the updater.timer
,
pushing it to the flake-update
branch so that it can build fresh
systems. This branch is setup as the source flake in all the MicroVMs,
so the following is all that is needed on a MicroVM-hosting server:
microvm -Ru $hostname
High Availability Deployment on Nomad
First, stop and delete /var/lib/microvm/$NAME
where the
systemd-managed MicroVMs live, or move the state to
/glusterfs/fast/microvms/$NAME
.
nix run .#nomad-$NAME
Secrets management
Secrets managment with PGP
Add your gpg-id to the .gpg-id file in secrets and let somebody reencrypt it for you. Maybe this works for you, maybe not. I did it somehow:
PASSWORD_STORE_DIR=`pwd` tr '\n' ' ' < .gpg-id | xargs -I{} pass init {}
Your gpg key has to have the Authenticate flag set. If not update it and push it to a keyserver and wait. This is necessary, so you can login to any machine with your gpg key.
Secrets Management Using sops-nix
Adding a new host
Edit secrets/.sops.yaml
:
- Add an AGE key for this host. Comments in this file tell you how to do it.
- Add a
creation_rules
section forhost/$host/*yaml
files
Editing a hosts secrets
Edit secrets/.sops.yaml
to add files for a new host and its SSH pubkey.
# Enter the secrets flake
cd secrets
# Get sops
nix develop
# Decrypt, start en EDITOR, encrypt
sops hosts/.../secrets.yaml
# Push
git commit -a -m YOLO
git push origin HEAD:master
# Go back to this flake
cd ..
# Update flake.lock file
nix flake lock . --update-input secrets
Laptops / Desktops
This repository contains a NixOS module that can be used with personal machines
as well. This module appends /etc/ssh/ssh_known_hosts
with the host keys of
registered HQ hosts, and optionally appends /etc/hosts
with static IPv6
addresses local to HQ. Simply import the lib
directory to use the module. As
an example:
# /etc/nixos/configuration.nix
{ config, pkgs, lib, ... }:
let
c3d2Config =
builtins.fetchGit { url = "https://gitea.c3d2.de/C3D2/nix-config.git"; };
in {
imports = [
# ...
"${c3d2Config}/modules/c3d2.nix"
];
c3d2 = {
isInHq = false; # not in HQ, this is the default.
mergeHostsFile = true; # Make entries in /etc/hosts form hosts.nix
enableMotd = true; # Set the login shell message to the <<</>> logo.
};
# ...
}