How to use the LSST software framework

The LSST science pipelines software is available under (see Software):

/cvmfs/sw.lsst.eu

At any moment you can know what releases (stable or otherwise) of the LSST software are available. Connect to the Login Farm and do:

tree -L 3 /cvmfs/sw.lsst.eu

In the sections below we present a very quick start guide to use that software and provide references to additional ressources on that topic.

Quick start guide

To use a given release of the software distribtion lsst_distrib, you must first log in to a host in the Login Farm:

ssh cca.in2p3.fr

Since all the hosts in the login farm run Linux, assuming you want to use w_2020_18 and your shell is bash do:

source /cvmfs/sw.lsst.eu/linux-x86_64/lsst_distrib/w_2020_18/loadLSST.bash

This will bootstrap your environment to use the specified release. As a result of executing this command, some environmental variables are extended or initialized, such as PATH, PYTHONPATH, LD_LIBRARY_PATH and EUPS_PATH.

To activate the whole set of the packages of this particular release, that is, making the commands available in you PATH and the Python packages in your PYTHONPATH do:

setup lsst_distrib

Alternatively, you can select a specific set of packages to activate. The LSST software uses EUPS for managing the set of packages which are part of a given release. EUPS allows you to select the packages you need to use in a work session. For instance, to use the command line tasks for processing CFHT images, instead of activating all the packages in lsst_distrib you can activate a subset of them:

$ setup obs_cfht
$ setup pipe_tasks

After these steps, your working environment is modified so that you can use the command line tasks (e.g. ingestImages.py, processCcd.py, etc.) and import Python modules in your own programs (e.g. import lsst.daf.persistence)

If you need to work with a different release of the stack, say w_2020_20, you must create a new terminal session and bootstrap your environment with the desired release. For instance:

# In a new terminal session
$ source /cvmfs/sw.lsst.eu/linux-x86_64/lsst_distrib/w_2020_20/loadLSST.bash
$ setup obs_cfht
$ setup pipe_tasks
$ processCcd.py --help

To retrieve the list of Python packages included in release w_2020_20, do:

$ source /cvmfs/sw.lsst.eu/linux-x86_64/lsst_distrib/w_2020_20/loadLSST.bash
$ conda list

Usage of lsst_sims is analogous as the usage of lsst_distrib.

Additional ressources

To get a deeper understanding of what you can do with the LSST software pipelines the resources below may help: