NGIPKGS

Ngipkgs is a collection of Nix packages and services for software projects that are supported through the Next Generation Internet (NGI) program of the European Commission.

Structure of Ngipkgs

The software in Ngipkgs can be divided into two broad categories: Nix packages, and NixOS services.

Nix packages can theoretically be built and run on any operating system that runs the Nix package manager. The output of building a Nix package is often a usable library or executable and most if not all of its dependencies. In Ngipkgs, these packages are all contained in the pkgs directory, and also listed in the file all-packages.nix.

NixOS services are nix packages that are designed to be configured through, and run persistently on, the NixOS operating system. These services are configured with options defined in the modules directory of Ngipkgs, and they are ready to be deployed to a new NixOS host (such as a container, VM, or physical machine) using NixOS configuration templates listed in the configs directory.

.
├── all-packages.nix              # import package directories here
├── configs
│   ├── all-configurations.nix    # import configuration files here
│   └── ...                       # add configuration directories here
├── flake.lock
├── flake.nix
├── modules
│   ├── all-modules.nix           # import module files here
│   └── ...                       # add module files here  
├── pkgs                          # add package directories here
├── README.md                     # this file

Add and build a package

For each package there is a directory in pkgs that contains a core default.nix file and possibly other files required to build the package. Each package directory must also be imported into Ngipkgs by adding a line to the file all-packages.nix. For example, this is the import line for building the libgnunetchat package:

libgnunetchat = callPackage ./pkgs/libgnunetchat { };

This package can then be built using the following command:

nix build .#libgnunetchat

Add and deploy a service

For each service there is a module file in the modules directory which is where most of the work is done to define the configuration for a service. Whereas the default.nix for a package usually somewhat corresponds to the upstream instructions for building and installing from source, the module for a service will correspond to the instructions for configuring and running the software persistently, including integration with other system components such as a systemd service or a web server config. Each module must also be imported into Ngipkgs by adding a line to the file modules/all-modules.nix.

A service has its NixOS configuration options defined in its module. To actually be used, this module file must be imported into a NixOS system configuration so that the options can be used and the service deployed. There is a directory in configs for each service that contains NixOS configuration template files for practical deployment of the service to different kinds of target systems, such as a container or a cloud VM. Each configuration must also be imported into Ngipkgs by adding a line to the file configs/all-configurations.nix. For clarity, the name given to the configuration in this file should include both the name of the service, and its target system. For example, this is the import line for deployment of liberaforms to a container:

  liberaforms-container = import ./liberaforms/container.nix;

This service can then be deployed on NixOS to a local container using the following comamand:

sudo nixos-container create libera0 --flake .#liberaforms-container

[TODO: Add details about how to do more production-like deployments that require non-default config options.]

[TODO: How to import all of Ngipkgs as an input to an existing NixOS configuration, in order to deploy a service alongside other services on the same virtual or physical machine.]

Continuous builds of packages with Hydra

Once they are merged into the main branch of the repo, all of the packages in Ngipkgs are a automatically built by a Hydra server. The results of these builds can be seen at https://hydra.ngi0.nixos.org/jobset/ngipkgs/main#tabs-jobs

Reasoning for creation of the Ngipkgs monorepo

• The user can discover ngi projects through a unified webpage and expectation is set that many of them are research projects.
• The developers get a unified code structure, CI & CD tooling, and a common PR and issue tracker which facilitates reviews.
• The funding organizations get an easy overview of the packaging situation.