Create an app including binary/library dependencies
I have an old application, EagleCAD, from 2014, a 32bit app, I managed to install it on my linux (Debian based, 64bits) and it works fine, but I had to look for and install some lib manually.
How can I package all this, the bin and libs, into one that I could easily re-install on about any distro? AppImage? Flatpak? Snap?
Copy all the libraries into one folder, then make a wrapper script using the LD_LIBRARY_PATH environment variable pointing to that folder before starting the application.
The modern way to run 10 year old binary applications is "don't", all of the technologies you listed are designed with a security focus and that means regular updates.
Me, I'm doing it, for myself, easier to install whenever I change distro, take a laptop, etc It's also to learn how to do it, I don't know how to create a snap/flatpak image, hence the post.
And it has nothing to do with an old app, it's to have an app and all its dependencies in a container
Most of these technologies combine some sort of sandboxing with the containerization part and the app has to be specifically adapted to use different ways to access data and system services where it needs to break the sandbox barrier.