NixOS is a very cool Linux distribution built on top of the Nix pkg manager. It’s very reliable and easy to deploy on multiple machines, however installing 3rd party software may be tricky.
Starting from version 3.2.1, you can run EVA ICS on NixOS. This article describes how to install it.
Install/enable mosquitto MQTT broker. Append the following lines to /etc/nixos/configuration.nix:
services.mosquitto.enable = true;
services.mosquitto.allowAnonymous = true;
services.mosquitto.users = {};
Then run
nixos-rebuild switch
Download and extract EVA ICS distribution:
cd /opt wget https://get.eva-ics.com/3.2.1/stable/eva-3.2.1-2019041702.tgz tar xzvf eva-3.2.1-2019041702.tgz mv eva-3.2.1 eva
NixOS has all required libraries for EVA ICS except OWFS libow (NixOS libow package is maintained by our team, but will be included in NixOS stable distribution later), so you must use included “nix” build file to compile it and then use package overlay.
“nix” files for EVA ICS load all required libraries. “Heavy” pandas/numpy Python modules are got from NixOS package repository, others are installed with pip.
Let’s build libow package:
cd /opt/eva/include/nixos/contrib/libow
nix-build -E "(import <nixpkgs> {}).callPackage ./default.nix {}"
Consider everything’s okay, then we can start EVA ICS setup (use “localhost” without username/password/SSL for MQTT):
echo "SYSTEM_SITE_PACKAGES=1" > /opt/eva/etc/venv echo "SKIP=pandas" >> /opt/eva/etc/venv nix-shell -I nixpkgs-overlays=/opt/eva/include/nixos/overlays /opt/eva/include/nixos/setup.nix --run /opt/eva/easy-setup
Great! Everything’s installed, now you can start EVA shell:
nix-shell /opt/eva/include/nixos --run eva-shell