New World file system layout

New World computers start life as out-of-the-box standard, minimally-configured Debian systems. The vast majority of software and configuration files on these computers is installed from standard Debian repositories by apt. Thus, to a very large extent, where things are in the file system is pretty-much dictated by Debian. This includes binaries, libaries, man pages and configuration files.

CSE-specific files — such as administration scripts, configuration files, teaching-related files., etc. — are largely located under either /etc or /usr/local. Below is a broad outline of what's where, why and how it gets there.

Path	Discussion
/etc	System configuration files. Most are left as they are out-of-the-box
/etc/auto*	Automounter configurations. See automounter operation
/etc/cron.d /etc/cron.daily	Directories containing scripts and cron configurations. CSE's contribution here mainly consists of scripts which regularly clean up left-over user session debris — files in /tmp, left-over virtual exam gaols, etc.
/etc/hosts	Automatically-generated list of all New World-known hosts and their IP addresses. Installed/updated by cf-agent. Used to avoid having to make DNS queries
/etc/krb5.conf	Kerberos configuration which points at UNSW's Active Directory servers for zID/zPass authentication of logins
/etc/ldap/ldap.conf	Configure OpenLDAP libraries and binaries (e.g., ldapsearch) to use CSE's own LDAP server, i.e., the UDB
/etc/libnss-ldap.conf /etc/pam_ldap.conf (symlink to /etc/ldap/ldap.conf)	Configure the PAM + NSS modules used for LDAP authorisation to point to CSE's own LDAP server, i.e., the UDB. See also /etc/nsswitch.conf
/etc/postfix/main.cf	Outgoing email configuration
/etc/sudoers.d/*	sudo configuration, particularly including priv-related sudo support
/etc/X11/xdm/xdm-config /etc/X11/xdm/Xresources /etc/X11/xdm/Xservers /etc/X11/xdm/Xsession-vlab /etc/X11/xdm/Xstartup-vlab	New or changed files to configure graphical login window on lab computers and VLAB, and specific startup scripts for VLAB sessions
/usr/local/acc	Passwords used by acc to access Active Directory and CSE's own User Database (UDB)
/usr/local/bin	Symlink to extrafiles/bin, i.e., to teaching-administered bin directory
/usr/local/etc	CSG-administered configuration and miscellaneous files including ARCH (the local host CPU architecture: Intel, AMD, ARM, etc.)
/usr/local/extrafiles	An entire file system sub-tree managed by teaching. Its contents are rsync'd from the cfengine hub holus-bolus. See /usr/local/extrafiles
/usr/local/extrapackages	Teaching-administered lists of additional standard Debian packages to be installed beyond the packages specified by CSG
/usr/local/games	Debian standard
/usr/local/include	Debian standard
/usr/local/infrastructure	Directories and files maintained by CSG
/usr/local/infrastructure/acc	Duplicate of /usr/local/acc
/usr/local/infrastructure/bin	Scripts maintained by CSG. This directory is used instead of /usr/local/bin to minimise confusion for students. The reasoning is that many of them may already be familiar with looking in /usr/local/bin (which teaching administers) while more savvy users (including CSG) will not have problems with looking for scripts in this current directory
/usr/local/infrastructure/bin/autofs_* /usr/local/infrastructure/bin/cifs_upcall_shim.sh	Automounter support scripts. See automounter operation
/usr/local/infrastructure/bin/classrun* /etc/sudoers.d/classrun	Run teaching's classrun
/usr/local/infrastructure/bin/get_device_temperature /usr/local/infrastructure/bin/getdiskstats /usr/local/infrastructure/bin/snmpd_loadaverage /usr/local/infrastructure/bin/snmpd_usercount	Used to extend information the snmpd daemon can return. See /etc/snmp/snmpd.conf
/usr/local/infrastructure/bin/start*	vx01 only: Configure user networking and run user VM's in /usr/local/qemu_machines for ZZEN9217. Se also ZZEN9217 H6 O.S. Fundamentals for Security: VM platform notes
/usr/local/infrastructure/bin/userresourcelimits.sh	Applies resource limits (such as PIDs, CPU and memory) to user sessions as the user logs in. See also man systemd-logind and /etc/systemd/logind.conf
/usr/local/infrastructure/bin/vmexec*<vr/> /etc/sudoers.d/vmexec*	Run user-defined virtual machines. See /usr/local/uservms
/usr/local/infrastructure/bin/vm /usr/local/infrastructure/bin/vm.sh /etc/sudoers.d/vm	Run CSG-maintained virtual machines for users. See /usr/local/vmimages
/usr/local/infrastructure/bin/vncsend* /usr/local/infrastructure/bin/vncrecv*	See vncsend
/usr/local/infrastructure/debpkgs_lists	CSG-managed lists of Debian packages to install
/usr/local/infrastructure/etc	CSG-maintained configuration files for CSG-developed systems
/usr/local/infrastructure/lib	CSG-maintained library files for CSG-developed systems
/usr/local/infrastructure/mlalias	Duplicate of /usr/local/mlalias
/usr/local/infrastructure/priv	priv scripts and "compiled" versions thereof. "priv" is a New World implemention of an Old World way of allowing users to run scripts as other users (notable root). This is a like sudo and, in fact, Old World-priv scripts can be copied into New World and then, when the New World priv is used to run them, it transparently converts them to work with sudo
/usr/local/infrastructure/privbin	Support components of the priv-to-sudo compiler
/usr/local/infrastructure/vlab	CSG-developed tools and scripts used to run the VLAB environment
/usr/local/lib	Debian standard
/usr/local/man	Debian standard, which is a symlink to share/man which actually, in turn, points into teaching-administered file system space. See /usr/local/share (below)
/usr/local/mlalias	Passwords used by mlalias to access CSE's User Database (UDB)
/usr/local/priv	Looks like old files
/usr/local/qemu_machines	Custom QEMU virtual machine images and support scripts. See also /etc/sudoers.d and /usr/local/infrastructure/bin for sudo configurations and start scripts, respectively
/usr/local/sbin	Debian standard
/usr/local/share	Symlink to extrafiles/share
/usr/local/src	Debian standard
/usr/local/tigervnc	Version of TigerVNC server as directly downloaded from the TigerVNC website. This is more recent than the version which comes with Debian. Used on VLAB servers
/usr/local/uservms	Experimental QEMU virtiual machines used for testing user-created-and-run VM's
/usr/local/vlab	Support scripts used for starting up the VLAB environment for each user
/usr/local/vmimages	CSG-managed VM's used by students