Infrastructure:Sysadmin Handbook

This page describes how to manage the infra. See rtfm.txt for a guide to build it from scratch.

This is NOT up to date as of 2019.

This covers setup of a Debian 9 VM on cyberdelia. This is current as of 2017-08-19.

Networks

We should have the following networks in place:

• Cyberdelia br0 on eth4 <--> eth1 on temp88191. This is the main LUUG network.
  • 10.0.0.1/22 for VTLUUG NAT (echarlie thinks we should only use a /24)
  • IPv6 via NDP proxying (static hosts configured in /root/scripts/router/ipv6/setup_ipv6.sh, but things should work without)
  • Global IPv4s via ARP proxying (edit /root/scripts/router/ipv4/Nat and edit $Inside_Hosts). Gateway is 128.173.88.1/22.
• Internal VM network (10.99.0.1/24). This is useful for sharing NFS insecurely, but be aware it only works on cyberdelia. If we get more VM hosts, they won't be able to use it without network reconfiguration. Several hosts also use this for LDAP
• "Internet" (a CNS portal) <--> eth0 on temp88191. LUUG only has one of these, and port security is probably enabled.

Most of our hosts consist of a "LUUG network" eth0 as the default route and an internal network for eth1.

DNS/DHCP:

• I think echarlie manages vtluug.org DNS? (It's on namecheap. we should unfuck this)
• jkh and Roddy own ece.vt.edu. DNS updates don't happen. echarlie can add IPv6-only records if needed to wuvt.vt.edu so we have PTRs.
• temp88191 runs DHCP and dnsmasq on eth1 (that is, 10.0.0.1/22). Edit /etc/dnsmasq.conf, add your static entries, and restart dnsmasq.

Auth

• apt-get -y install sssd-ldap nscd
• vim /etc/sssd/sssd.conf

[sssd]
config_file_version = 2
services = nss, pam
domains = LDAP
debug_level = 5

[nss]
filter_users = root,ldap,named,avahi,haldaemon,dbus,radiusd,news,nscd
homedir_substring = /home

[domain/LDAP]
id_provider = ldap
auth_provider = ldap
ldap_search_base = dc=vtluug,dc=org
ldap_tls_reqcert = allow
ldap_uri = ldaps://razor.vtluug.org

Storage

• apt-get -y install nfs-common
• vim /etc/idmap.conf

[General]

Verbosity = 0
Pipefs-Directory = /run/rpc_pipefs
# set your own domain here, if it differs from FQDN minus hostname
# Domain = localdomain
Domain = vtluug.org

[Mapping]

Nobody-User = nobody
Nobody-Group = nogroup

• vim /etc/fstab

10.99.0.1:/tank/nfs/home			/home	nfs	soft,auto,nodev	0	0
10.99.0.1:/tank/nfs/share 		/tank/nfs/share	nfs	soft,auto,nodev,nosuid	0	0
10.99.0.1:/tank/nfs/scratch		/tank/nfs/scratch	nfs	soft,auto,nodev,nosuid	0	0
10.99.0.1:/tank/nfs/files		/tank/nfs/files		nfs	soft,auto,nodev,nosuid	0	0

• mkdir -p /tank/nfs/{share,scratch,files}
• systemctl restart sssd
• mount -a

Testing

To verify that this worked: su to your user, cd, and you should be able to modify your files.