Purchase one of these rigid plastic (or carton) tubes – they are usually sold for storing and/or mailing documents and drawings. In my experience they are cheaper than many of the dedicated items sold for storing needles, and what’s more, they are long enough to store even the longest knitting needles.
If you are really into being eco-friendly, you will seek out discarded textile industry tubes for the same purpose. I have one about 130 cms long which I will be cutting into 2 or 3 sections to hold my long rulers. It has a wider diameter than the plastic tubes I mentioned previously – about 8 cms across. You don’t need to, but can of course decorate these tubes if you like.