AppImageUpdate lets you update AppImages in a decentral way using information embedded in the AppImage itself. No central repository is involved. This enables upstream application projects to release AppImages that can be updated easily. Since AppImageKit uses delta updates, the downloads are very small and efficient.
This is an implementation of AppImageUpdate in modern C++ (C++11, to be precise).
This is beta-level code. It works, and most features available work fine. However, in this state, there is not much real world experience with the application. Please report any issues on the bug tracker.
Notice how quick the update was. Combined with fully automated continuous or nightly builds, this should make software "fluid", as users can get the latest development versions very rapidly.
If you have the optional appimaged daemon installed, then it can use AppImageUpdate enable right-click updates in the launcher:
Here are some concrete use cases for AppImageUpdate:
With AppImages allowing upstream software developers to publish applications directly to end users, we need a way to easily update these applications. While we could accomplish this by putting AppImages into traditional
rpm packages and setting up a repository for these, this would have several disadvantages:
AppImageUpdate to the rescue.
AppImageUpdate has been created with specific objectives in mind.
In order for AppImageUpdate to do its magic, Update information must be embedded inside the AppImage. Update information is what tells AppImageUpdate vital data such as:
While all of this information could simply be put inside the AppImage, this could be a bit inconvenient since that would mean changing the download server location would require the AppImage to be re-created. Hence, this information is not put into the file system inside the AppImage, but rather embedded into the AppImage in a way that makes it very easy to change this information should it be required, e.g., if you put the files onto a different download server. As you will probably know, an AppImage is both an ISO 9660 file (that you can mount and examine) and an ELF executable (that you can execute). We are using the ISO 9660 Volume Descriptor #1 field "Application Used" to store this information.
You should be able to add this repository (with this branch) as a submodule
in your own repository. When using CMake, call
add_subdirectory() on the
submodule path. The header directories should then be added globally. All
you need to do is link your application against
example by calling
Note that as mentioned previously, this project uses C++11. However, care
has been taken to make public headers work in older versions of C++ as
well. Therefore, it should not be necessary to set
-std=c++11 etc. in projects using this library. If you notice that this
stops working, please open an issue.
For details on the licensing of the libraries AppImageUpdate uses, please see their documentation.
The code of AppImageUpdate is licensed under the terms of the MIT license. Please see LICENSE.txt for details.
The sample AppImageUpdate GUI is based in part on the work of the FLTK project (http://www.fltk.org). We are interested in adding Qt and Gtk+ versions.
If you have questions, the developers are on