How to add weather to i3status in NixOS

Question

Adding weather to the status bar in i3 can be done in several ways, including:

• py3status
• piping i3status to a custom bash script

i3status does not allow including arbitrary shell commands in the configuration file. NixOS environment for Python requires further configuration, and when I pipe i3status I lose the color formatting. How do I preserve color formatting and add weather without adding additional i3 extensions?

Answer 1

Add a shell script to /etc/nixos/i3/weather.sh (modified from Reddit user @olemartinorg):

#!/bin/sh
# weather.sh
# shell script to prepend i3status with weather

i3status -c /etc/nixos/i3/i3status.conf | while :
do
  read line
  weather=$(cat ~/.weather.cache)
  weather_json='"name":"weather","color":"#FFFFFF", "full_text":'
  weather_json+=$(echo -n "$weather" | python -c 'import json,sys; print json.dumps(sys.stdin.read())')
  weather_json+='},{'

  # Inject our JSON into $line after the first [{
  line=${line/[{/[{$weather_json}
  echo "$line" || exit 1
done

Create a cronjob in your NixOs configuration.nix:

services.cron = {
    enable = true;
    systemCronJobs = [
      "*/5 * * * *      USERNAME    . /etc/profile; curl -s wttr.in/Osnabrueck?format=3 > ~/.weather.cache"
    ];
  };

Replace "Osnabrueck" with your city name, and USERNAME with your username. This creates a file .weather.cache which will contain the local weather as a one-liner.

Finally, update i3.conf, replacing i3status with the path to your script:

bar {
    status_command /etc/nixos/i3/weather.sh
    tray_output primary
}

nixos-rebuild switch and start i3 ($mod+Shift+R). You should now see your weather at the bottom (or wherever your i3 status bar displays).