Development for LHC@home

Ubuntu 18.10
Install CVMFS (from the docs)

wget https://ecsft.cern.ch/dist/cvmfs/cvmfs-release/cvmfs-release-latest_all.deb
sudo dpkg -i cvmfs-release-latest_all.deb
rm -f cvmfs-release-latest_all.deb
sudo apt-get update
sudo apt-get install cvmfs

Configure CVMFS

sudo wget https://lhcathomedev.cern.ch/lhcathome-dev/download/default.local -O /etc/cvmfs/default.local
sudo echo "/cvmfs /etc/auto.cvmfs" > /etc/auto.master.d/cvmfs.autofs 

Ensure autofs is running with the latest configuration

sudo systemctl autofs restart

Test CVMFS

 cvmfs_config probe

Probing /cvmfs/cernvm-prod.cern.ch... OK
Probing /cvmfs/grid.cern.ch... OK
Probing /cvmfs/sft.cern.ch... OK

Make sure the python command is available

sudo apt-get install python

Debian Stretch:
Follow the Ubuntu guide and do the following to enable user namespaces:
Unfortunately, it looks like that this fix is only temporarily, since after rebooting the system the value in that file is again 0 and the unshare command does not work anymore.
To fix this for good, I adapted the sysctl.conf file in order to make the value of "/proc/sys/kernel/unprivileged_userns_clone" to be persisant 1.

sudo echo "kernel.unprivileged_userns_clone = 1" >>  /etc/sysctl.conf
sudo sysctl -p

CentOS 7
Install CVMFS

sudo yum install https://ecsft.cern.ch/dist/cvmfs/cvmfs-release/cvmfs-release-latest.noarch.rpm
sudo yum install -y cvmfs

Configure CVMFS

sudo wget https://lhcathomedev.cern.ch/lhcathome-dev/download/default.local -O /etc/cvmfs/default.local
sudo echo "/cvmfs /etc/auto.cvmfs" > /etc/auto.master.d/cvmfs.autofs 

Ensure autofs is running with the latest configuration

sudo systemctl autofs restart

Test CVMFS

 cvmfs_config probe

Probing /cvmfs/cernvm-prod.cern.ch... OK
Probing /cvmfs/grid.cern.ch... OK
Probing /cvmfs/sft.cern.ch... OK

Increase the maximum number of user namespaces

sudo echo 100 > /proc/sys/user/max_user_namespaces

Debian Stretch:
Follow the Ubuntu guide and do the following to enable user namespaces:
Unfortunately, it looks like that this fix is only temporarily, since after rebooting the system the value in that file is again 0 and the unshare command does not work anymore.
To fix this for good, I adapted the sysctl.conf file in order to make the value of "/proc/sys/kernel/unprivileged_userns_clone" to be persisant 1.

sudo echo "kernel.unprivileged_userns_clone = 1" >>  /etc/sysctl.conf
sudo sysctl -p

Sry to be fussy, but the shown command "sudo echo...." does not work for debian. Using e.g. sed will work.
So I would suggest something like this:

Debian Stretch:
Follow the Ubuntu guide and do the following to enable user namespaces:
For enabling user namespaces for every user permanently, type

sudo sed -i '$ a\kernel.unprivileged_userns_clone = 1' /etc/sysctl.conf
sudo sysctl -p

If you want to enable user namespaces only temporarily, type

sudo su -c 'echo 1 > /proc/sys/kernel/unprivileged_userns_clone'

You will have to execute this command after every system reboot in order to be able to crunch native Theory tasks.

@Laurence (or any admin/moderator): You can delete this command if you want in order to keep this thread clean.

lhcathome has had for a while atlas native tasks. A configuration file for atlas native cvmfs is located in /etc/cvmfs/default.local.

If a volunteer is already running atlas native tasks and decides to add the capability to run theory native tasks, when they enter this command

sudo wget https://lhcathomedev.cern.ch/lhcathome-dev/download/default.local -O /etc/cvmfs/default.local

it will overlay the atlas cvmfs configuration file at that location.

lhcathome has had for a while atlas native tasks. A configuration file for atlas native cvmfs is located in /etc/cvmfs/default.local.

If a volunteer is already running atlas native tasks and decides to add the capability to run theory native tasks, when they enter this command

sudo wget https://lhcathomedev.cern.ch/lhcathome-dev/download/default.local -O /etc/cvmfs/default.local

it will overlay the atlas cvmfs configuration file at that location.

If you are already running ATLAS native the only entry you really need from that file is "CVMFS_REPOSITORIES=".
The resulting line (ATLAS + Theory) should look like this:

CVMFS_REPOSITORIES="atlas.cern.ch,atlas-condb.cern.ch,grid.cern.ch,cernvm-prod.cern.ch,sft.cern.ch"

Then save your /etc/cvmfs/default.local and run "cvmfs_config reload" to activate the changes.