Install and configure cvmfs on MacOS

Step 1: install MacFuse and then reboot.

https://osxfuse.github.io

Step 2: install cvmfs

https://cernvm.cern.ch/fs/

Step 3: Create /etc/cvmfs/default.local file with these contents. (Note that we must specify a non-standard mount dir for MacOS since it will not allow us to create a directory in "/". Specifically, we can't create /cvmfs

   CVMFS_MOUNT_DIR=/opt/cvmfs
   
   CVMFS_REPOSITORIES=oasis.opensciencegrid.org,eic.opensciencegrid.org,singularity.opensciencegrid.org
   
   CVMFS_CLIENT_PROFILE=single
   CVMFS_HTTP_PROXY=DIRECT

Step 4: Create the mount point directories and mount the desired volumes. Note here this is being done manually instead of relying on the CVMFS_REPOSITORIES setting in default.local. I'm not sure why it needs to be done this way, but it does.

   sudo mkdir /opt/cvmfs/oasis.opensciencegrid.org
   sudo mkdir /opt/cvmfs/eic.opensciencegrid.org
   sudo mkdir /opt/cvmfs/singularity.opensciencegrid.org
   
   sudo mount -t cvmfs oasis.opensciencegrid.org /opt/cvmfs/oasis.opensciencegrid.org
   sudo mount -t cvmfs eic.opensciencegrid.org /opt/cvmfs/eic.opensciencegrid.org
   sudo mount -t cvmfs singularity.opensciencegrid.org /opt/cvmfs/singularity.opensciencegrid.org