How to add weather to i3status in NixOS - weather

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).