What kind of virtualization, VM or Containers?

Many questions to be tackled under this item:
- building vs running
- our software vs 3rd party libraries vs system libraries
- LAT calibrations
- connection to mysql db
Following June 6th 2017 meeting, we'll initially focused on Containers as it's very unlikely that the SLAC farm will move to Virtual Machines (Brian's comment)
- For SLAC farm - docker containers for GlastRelease. Need docker registry
- Use their system run to RHEL6 container, but batch host is RHEL7.
- Johan: VMs might still be useful for code development and debugging, for GR in particular.

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Virtual machines running in a cloud environment or on a farm made of virtual nodes
just a simple VM for developers or end users

a few technologies to consider Docker, Shifter (Nersk for HPC) and Singularity
advantages over a full VM usually are:
- light weight
- better performance
- container has to be carefully built
Docker: the container
Shifter: NERSC container optimized for HPC
Singularity: containers for scientist

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Details for main packages

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