ATLAS@Home native app on Ubuntu Bionic

In case you haven't heard: the ATLAS@Home app is available for download in Linux. This app normally runs inside a Virtualbox VM, which is a good way to get things working with different operating systems, but adds the overhead of a virtual machine. This can be avoided when ATLAS@Home is running on your Ubuntu Bionic computer by following the steps outlined below.

First, let's make sure you have the essentials:

sudo apt update && sudo apt -y dist-upgrade
sudo apt install attr autofs curl boinc-client fuse gawk gdb lsb-release perl psmisc python2.7 singularity-container uuid-dev uuid wget
Next step is to add the repositories and install cvmfs.

wget https://ecsft.cern.ch/dist/cvmfs/cvmfs-release/cvmfs-release-latest_all.deb \
http://cvmrepo.web.cern.ch/cvmrepo/apt/pool/bionic-testing/main/cvmfs-config-default_1.4-1_all.deb \
http://cvmrepo.web.cern.ch/cvmrepo/apt/pool/bionic-testing/main/cvmfs_2.5.1~1+ubuntu18.04_amd64.deb
sudo dpkg -i cvmfs*.deb
Before you continue, however, you may have noticed the following warning:

Warning: this distribution is not supported. Using Ubuntu 12.04 packages as fallback.
If you don't get this: excellent! If you do: it simply means that the repository hasn't been correctly configured for Bionic yet. The fix is simple enough:

sudo sed -i 's/precise/bionic/g' /etc/apt/sources.list.d/cernvm.list
Note that an update to the cvmfs-release package may overwrite these changes, so you'll have to do it again.
Also note that, at time of writing, the Bionic repos have not been set up correctly, which is why you need to manually download the packages. If the packages change (usually due to a version update), you can find the required packages at http://cvmrepo.web.cern.ch/cvmrepo/apt/pool/bionic-testing/main/. Once the repositories are set up properly, the packages will update as expected.

And now a few more steps:

sudo cvmfs_config setup
printf "CVMFS_REPOSITORIES=atlas.cern.ch,atlas-condb.cern.ch,grid.cern.ch\nCVMFS_HTTP_PROXY=DIRECT\n" | sudo tee /etc/cvmfs/default.local
sudo systemctl restart autofs
Finally, check everything is okie dokie:

$ cvmfs_config probe
Probing /cvmfs/atlas.cern.ch... OK
Probing /cvmfs/atlas-condb.cern.ch... OK
Probing /cvmfs/grid.cern.ch... OK
Cushty.

Notes:

• If you have a proxy, you should use that in place of CVMFS_HTTP_PROXY=DIRECT. However, this must be set to something or it will fail.
  
• If you have a lot of machines and a server which runs all the time (such as a proxy server), you will probably be better off installing cvmfs on the server, and exporting the share over NFS. This will save a lot of duplication and inbound bandwidth.
  
• At time of writing, none of the LHC@Home applications run on GPU for mainly historical reasons. Given improvements in the way VMs are handled this may change in the future. If you wish to use your GPU then you will also need to install the relevant drivers and libraries.
  

References:

1. https://cernvm.cern.ch/portal/filesystem/quickstart
   
2. https://lhcathomedev.cern.ch/lhcathome-dev/forum_thread.php?id=348
   
3. http://cvmrepo.web.cern.ch/cvmrepo/apt/pool/
   
4. https://twiki.cern.ch/twiki/bin/view/CvmFS/ClientSetupCERN