1. Print the files.
2. Apply super glue to the side rails of the solenoid valve and glue a peice of foam on each sides 3.Wire the Relay + The 12V adaptor + Outdoor power cable 4.With Hot Glue (NOT SUPER GLUE) fix the components inside the plastic box
3. Again with Hot Glue OR Aquarium Grade DAP fill the side of the valve and the opening for so you get a water tight seal. 6.Close the box.

As for the code i use home assistant with Esphome and since it's a simple relay: https://esphome.io/cookbook/relay.html

For the automation depending on the weather elements there's plenty of videos and tuto's out there but here's the one i followed: (you can skip to 14:45) https://www.youtube.com/watch?v=eUsA-8u-E3o

For more control create a button in home assistant dashboard and you can add open weather maps to create custom automations.

There's multiple ways/parts you can buy to achieve this project here's what i bought and assembled:

Materials used:

M3 (10-15mm) Screws: https://www.aliexpress.com/item/32963722509.html

Time 4 Crafts 12-Piece Foam EVA Sheets, 9 x 12 inches, Black https://www.amazon.com/Time-Crafts-sheet-inches-Black/dp/B0764LX5Q4

3/4" Plastic Solenoid Valve 12V: https://www.aliexpress.com/item/1005001369725159.html

12V Charger (2A): https://www.aliexpress.com/item/32961533195.html

ESP8266 ESP-01 12V: https://www.aliexpress.com/item/4001149691409.html

Outdoor cable: Dollar Store

For minimal soldering i used:

Quick wiring connector: https://www.aliexpress.com/item/1005003655645428.html