extract the name of towns from all (german) islands

Hi,
I want to use osm datas to create a simple txt file from all islands (in germany).

But I don’t know whats the best practice to handle this.
My resultfile should look like:
Binz, Ruegen
Westerland, Sylt

Can I use some tools like osmosis or osmfilter or must I install a Postgres server and building some queries for these job?

thank you