You know what I'm talking about, these food tubes that are popular for tomato paste, or pesto.  Searching for 'food in tube' or 'how to make your own tomato paste in tube' yields mixed results, so I'm wondering if I'm even calling this preservation method correctly. I personally think they are amazing when cooking with small quantities (as opposed to cans), and I would like to 'tube' my own pastes, pestos, creams, purees, mustards, and whatnot. However I have a very hard time to find any DIY info on what to buy, what tools are needed, etc. Any advice on where to look for information about this process on a DIY standpoint? 
Tubes like that are assembled with the bottom open (so at that point it's a cylinder, closed at the cap end), filled, and then folded and heat-sealed at the bottom. The filling is done with a rigid baster-like thing to minimize air bubbles. Here's a video of the process. There's no particular reason you couldn't do most of this at home, with the exception of the heat sealer (though you might be able to repurpose a vacuum sealer). The real issue would be sourcing the tubes, which I doubt are generally available if you're buying less than a thousand. If your primary goal is easy dispensability, have you considered a large food-safe syringe? Easy to find, similar in functionality, and while they're more expensive than foil tubes they're also reusable. 