Using the SCAS

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The LCAS/LCMAPS GT4-interface for Globus GridFTPd, Gatekeeper and GSI-OpenSSHd and gLExec all share the LCMAPS framework as their mapping back-end. It can be configured to use the SCAS client LCMAPS plug-in. This will contact the SCAS service to trigger an authorization decision and, on a positive result, return a mapping result. This will then be input for the LCMAPS user mapping back-end of gLExec to continue.


Installation

Add the scas-client plugin to the set of RPMs on your machine. The SCAS client LCMAPS plug-in has a requirement on the SAML2-XACML2 C Library.

Configuration

Configure the LCMAPS You would add to /opt/glite/etc/lcmaps/lcmaps.db or /opt/glite/etc/lcmaps/lcmaps-glexec.db:

scasclient = "lcmaps_scas_client.mod"
            " -capath /etc/grid-security/certificates/"
            " -endpoint https://graszaad.nikhef.nl:8443"
            " -resourcetype wn"
            " -actiontype execute-now"

and the following policy execution flow at the end:

# policies
glexec_get_account:
verify_proxy  -> scasclient
scasclient -> posix_enf

Note: This example assumes a verify_proxy and posix_enf plug-in to be configured in the same lcmaps.db file.

Usage: gLExec on the WN

The most complex use case is that of the Multi User Pilot Job (MUPJ).

To test the plug-in the X509_USER_PROXY environment variable must be set for gLExec.