Allow user config for default install dir and directories to search for updates

[HaleTom]

Issue background

I store my AppImages in /opt, which has permission g+w set for wheel.

I'd like to be able to set that as the default install directory for new AppImages.

Additionally, sometimes opinionated programs want to install AppImages to other locations, so I want to also specify those for updating purposes.

Suggested improvement

Please allow a config file in which that the user can set their own preference:

• Directory for installation
• DirectorIES to search for updates

XDG Base Directory Specification says:

There is a single base directory relative to which user-specific configuration files should be written. This directory is defined by the environment variable $XDG_CONFIG_HOME.

Therefore, I'd suggest the app's config file be: $XDG_CONFIG_HOME/AppManager.{conf,yaml,toml,...}

Related issue

[FR] Use XDG_APPLICATIONS_DIR instead of ~/Applications #30

[kem-a]

I'll see what I can do. Changing default install location is a little finicky since whole code structure relies on it

[ivan-hc]

@kem-a To write to /opt, you need root privileges. Unless you create a directory where you can only read/write once and move all the AppImages there, it would be a mess, even with updates.

When delta updates are performed, a new temporary file is created next to the AppImage until the update is complete.

It would therefore be necessary to create a writable directory in /opt.

@HaleTom However, for backup purposes, it's best to save everything in $HOME, or at least in a directory where you can write without necessarily having to use root privileges.

[HaleTom]

To write to /opt, you need root privileges.

I don't -- as I said in the first line, my /opt has permission g+w set for group wheel. It could be appimage or any other group :)

My point is that I should be able to specify any directory to which my user has write permissions, and use that for installation.

[HaleTom]

An edge case would be if one of the "search for updates" directories isn't writable -- then install the update in the "install" directory instead. Otherwise, try to update an appimage in the directory in which it currently resides -- some appImages may be called by scripts and expect to be in a particular place.

[kem-a]

I'm confused. If you have set write access to /opt then why don't you use it?

AppManager does not have config files, everything preferences related is stored in dconf, everything app related is stored in ~/.local/share` .json registry.