Grid5000
On the Grid5000 testbed experiment platform there is no first class support for Nix (right now). NixOSCompose relies at least on the presence of the Nix store on the frontend commands that are not init and build and access to the Nix package manager for those two. To have it, we need to use some workarounds. Except for the init and build commands (see details here), that will requiere a local installation of Nix followed by a chroot, the rest of the commands are only relying on Python. It means that for building your distributed environments you will need the reservation of ressource
Nix installation on frontend
We are going to use the script nix-user-chroot.sh. It provides Nix without root permissions on the frontend. At its first call it will install the Nix package manager and create all required folders in your home folder (e.g. ~/.nix/store/) then change the apparent root directory so that the nix command works as expected. All subsequent call to this script will only do the second part followed by the activation of the nixcommand.
curl -L -O https://raw.githubusercontent.com/oar-team/nix-user-chroot-companion/master/nix-user-chroot.sh
chmod +x nix-user-chroot.sh
On a interactive session on a node (using oarsub -I)
login@dahu-17:~$ ./nix-user-chroot.sh
...
Activate Nix
login@dahu-17:~$
The call nix-user-chroot.sh can be done either on the frontend or on a node. Doing it on the frontend is practical when you want to exploit the Nix store (e.g. when using nix shells) but we advise to avoid building phases on the frontend (any commands that will populate the Nix store).
TODO interesting but not clear enough...
Installation of NixOSCompose
The threee following sections describe alternative approaches to install NixOSCompose.
Local installation with a poetry shell
Instal poetry locally in your home
curl -sSL https://install.python-poetry.org | python3 -
Clone NixOSCompose project then install all python dependencies thanks to Poetry. Finally activate the virtualenv.
TODO avec le changement de l'arborescence des dossiers les commandes ci dessous vont changer... cd nixos-compose/src ou autre.
git clone https://gitlab.inria.fr/nixos-compose/nixos-compose.git
cd nixos-compose
poetry install
poetry shell
For further use only poetry shell is needed.
Python virtualenv with poetry then poetry shell
Similar to the method above but avoid the poetry instalation in your home directory and instead does it in a virtualenv.
git clone https://gitlab.inria.fr/nixos-compose/nixos-compose.git
cd nixos-compose
python3 -m venv /path/to/nxcEnv
. /path/to/nxcEnv/bin/activate
pip install poetry
poetry install
deactivate
Drops you in the virtualenv with NixOSCompose available.
Nix chroot on frontal with nix develop
As seen in the local installation it is preferable to use the same nxc version that the one used in the project. The downside of this method is that you are loosing access to the specific commands of the platform (e.g. oarsub command is not acessible in a nix-shell) so you need either do your reservation of ressources before entering those commands or use multiple terminal or a terminal multiplxer (for instance tmux).
./nix-user-chroot.sh #activate Nix
nix develop .#nxcShellLite