Write rpm spec file for appimaged

[probonopd]

We need to write a rpm spec file so that it can be included in gnome-software CI which is based on Fedora. This issue is to keep track of the progress.

cc @Conan-Kudo

[probonopd]

Actually it looks like CMake can do this, similar to what we do for debs. I have started in https://github.com/AppImage/appimaged/compare/feature/rpm?expand=1 but am stuck. Help appreciated.

[TheAssassin]

It doesn't just look like it can, it is used in other projects like AppImageLauncher.

CPack works like "set all the variables, then run cpack -G <generator> (RPM in this case)".

Documentation: https://cmake.org/cmake/help/latest/cpack_gen/rpm.html#cpack_gen:CPack%20RPM%20Generator

Example: https://github.com/TheAssassin/AppImageLauncher/tree/master/cmake, specifically https://github.com/TheAssassin/AppImageLauncher/blob/master/cmake/cpack_rpm.cmake.

[TheAssassin]

Also, this issue is about writing a spec file, which CPack doesn't do (see the documentation). CPack just creates an RPM package. You should open another issue.

[probonopd]

Also, this issue is about writing a spec file, which CPack doesn't do (see the documentation). CPack just creates an RPM package. You should open another issue.

Done that. Just having an RPM is exactly what we need for #25.