Apps for Server/DC are almost all packages which you can download to a machine and then upload on to your server/dc install with the "upload app" link.
If you dig through the marketplace pages for the app you want, you will find a list of versions of the app, which then links to a direct download of the package (it will be a .jar or .obr file), but you'll need to check what versions are valid for your version of Jira.
If you were to able to use the built-in "install new app" function, it would be doing the same thing you have to do manually - it finds the app in the marketplace, reads the version information and downloads and installs the latest version compatible with your current Jira server version.
The last bit you have to do is paste a licence key into the licence box after you've purchased one. That's also the one bit the plugin manager does not do for you.
To answer your specific questions:
- do the add-ons work without internet connection
- Yes, mostly. Some might require an internet connection if they are apps that try to talk to other systems over the internet, but that should be obvious from the app description
- are there any restrictions?
- No, manual upload works the same as the marketplace stuff doing all the work for you
- Is it possible in general?
- Is it only needed for the license key?
- How does it deal with the licenses?
- the licence key is a copy and paste, whatever the installation method
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.