pymongo has to be manually installed

[Mapel]

I followed this manual for deployment: https://docs.alerta.io/gettingstarted/tutorial-1-deploy-alerta.html on Ubuntu 22.04, but got this error:

Dec 19 14:03:47 alerttest alertad[6560]: File "/opt/alerta/lib/python3.10/site-packages/alerta/database/base.py", line 43, in load_backend Dec 19 14:03:47 alerttest alertad[6560]: raise ImportError(f'Failed to load {backend} database backend') Dec 19 14:03:47 alerttest alertad[6560]: ImportError: Failed to load mongodb database backend

After some searching I found this old issue, where the error was the missing psycopg2-binary package.
I tried to install pymongo manually and this solved the problem.

Please add pymongo as a dependency for automatic installation or add an instruction for it to the deployment manual.

[hyberdk]

you are more than welcome to make a PR with the updated steps ;-)