KNIME how two group several extensions under one category

Dear community members,

I have a question about python extension development. I made a number of python extensions and want to group them under one “Group” (like “KNIME Server extensions”, for example in the screenshot). But each of them is under it’s own group, that is not convinient. My question is how to provide one group for a number of extensions?

Hi @pirotex,

If you want to distribute several extensions together on one update site, you need to create a composite update site, that collects your plugins.
Take a look at this example repository that shows how to do this: GitHub - knime-community/composite-update-site-example


@gab1one Your reply is cut off :wink:

Sorry, I missclicked and it got posted too early. Original answer is now updated.

1 Like

Dear @gab1one,

Thanks for the answer. I did it, but still has a problem at build stage. When I try to do mvn package I have:

[INFO] Resolving dependencies of MavenProject: @ /home/sergeyadmin/projects/KNIME_our_extensions/pom.xml
[INFO] {osgi.os=linux,, org.eclipse.update.install.features=true, osgi.arch=x86_64}
[ERROR] Cannot resolve project dependencies:
[ERROR] Software being installed: 0.1.0
[ERROR] Missing requirement: 0.1.0 requires ‘org.eclipse.equinox.p2.iu; [0.1.0,0.1.1)’ but it could not be found

Looks like maven does not know where are KNIME internal libraries. How to fix it? My pom and category files are attached.
category.xml (646 Bytes)
pom.xml (2.6 KB)

Hi @pirotex,

This error says that the build can not find your extension, you need to configure the repository url to point to the repository folder generated by the bundling script.
The right folder has these files in it:


Dear Gabriel,

Thanks for the very quick answer! Yes, I checked it, my repository is correct there are these files inside, and I can use it to install my extensions from KNIME. So I believe that was not the problem with path. Moreover, if I deliberately change the path to the wrong one, I have another type of error with mvn package.

I also checked it with the local path to the repo and with http server. There is no difference. And, looking at webserver, logs, one can see that maven takes files from repo correctly

Serving HTTP on port 8000 ( … - - [25/Oct/2022 11:50:18] “GET /p2.index HTTP/1.1” 200 - - - [25/Oct/2022 11:50:18] “HEAD /content.xml.xz HTTP/1.1” 200 - - - [25/Oct/2022 11:50:18] “GET /content.xml.xz HTTP/1.1” 200 -
Screenshot from 2022-10-25 11-52-16

Hi @pirotex,

In that case you need to investigate if the names of the features in the category.xml file are correct as well as their version constraints. I recommend you to set the version range to "0.0.0" this ensures that it always uses the latest version.