Originally Posted at: https://forum.minetest.net/viewtopic.php?id=4375
A newer mod, based on this one, is here: https://github.com/Mossmanikin/fishing

Includes:
    a fish (can be cooked or eaten raw),
    fishing poles,
    worm (bait),
    sushi
To get worms for bait you must dig in dirt (without grass) by hand. There is a default 30% chance that you will find one. This can be configured in init.lua, as well as the chance of catching a fish. Or, you can use "/giveme fishing:bait_worm".
To catch a fish, use a baited fishing pole on a water node.
Depends:
    To craft a fishing pole: (or you can use "/giveme fishing:pole")
        ropes or moreblocks or farming
            I suggest using my modified version of ropes. Get it here.
            This also modifies moreblocks:rope to be used as ropes:rope -- which is really handy.
    To craft sushi: (or you can use "/giveme fishing:sushi")
        plantlife

Code:WTFPL
Textures:
<http://www.planetminecraft.com/texture_pack/wolfhound/>

TODO:
    item wear,
    automatic re-baiting option,
    different types of bait/fish/sushi,
    sounds,
    nets and traps