Tensorflow GPU / CUDA installation on Ubuntu

I have set up a Ubuntu 18.04, and tried to make Tensorflow 2.2 GPU work (I have a Nvidia/CUDA graphic card) with Python. Even after reading the documentation https://www.tensorflow.org/install/gpu#linux_setup, it failed (see below for details about how it failed).

Question: would you have a canonical "todo" list (starting point: freshly installed Ubuntu server) on how to install tensorflow-gpu and make it work, with as few steps?

Notes:

• I have read many similar forum posts, and I think that having a canonical "todo" (from a fresh Ubuntu install to having tensorflow-gpu working) would be interesting, with a few steps / bash commands

• the documentation I used involved

    export LD_LIBRARY_PATH...
  
    # Add NVIDIA package repository
    sudo apt-key adv --fetch-keys http://developer.download...
    ...
    # Install CUDA and tools. Include optional NCCL 2.x
    sudo apt install cuda9.0 cuda...
  

  Even after a lot of trial and errors (I don't copy/paste all the different errors here, would be too long), then at the end:

    import tensorflow
  

  always failed. Some reasons included ImportError: libcublas.so.9.0: cannot open shared object file: No such file or directory. I have already read the relevant question here, or this very long (!) github issue.

• After some trial and error, import tensorflow works, but it doesn't use the GPU (see also Tensorflow not running on GPU).

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