With the release of version 0.9.0 of the Extension Manager more extensions become available after the installation of Docker. On DietPi it is easy to add Docker to the mix, you can install it via the dietpi-software installer. Docker can be found in the ‘System Stats / Management’ group within ‘Software Optimized’.
Alternatively, you can install from the command line:
dietpi-software install 162
If you perform a clean install you have to install both the Extension Manager and Docker:
dietpi-software install 86 162
I created two videos, one that demonstrates the clean install:
And one that demonstrates the upgrade: