Equipment/Denning

Denning
Model	Nexcom DNA1110
Sub-category	Systems
Status	Good working order
Training requirement	yes
Training link	Unknown
ACnode	no
Owner	LHS
Origin	donation from Tgreer
Maintainers	Sysadmin team

Denning

Runs the non-vital services that used to run on Boole. Might get used for other stuff as well. Same hardware as Boole

Runs zone minder and has a not very good 4 port TV capture card in it, currently connected to the 3 yard cameras and the rear lobby camera.

Also a netboot server, provides:

• Diskless i386 and amd64 debian wheezy
• Rescue and Install for debian wheezy.
• partition magic
• memtest
• dban
• Voyage (a minimised debian disto that can run from readonly media) Warning : the Voyage auto install kernel will reformat things they are booted on without prompting.

Also runs ansible for setting up machines in the space.

Issues

Has only a single mechanical harddrive so vulnerable to data loss. Maybe look at adopting this for netboot stuffs: https://github.com/askarel/Pantoufle

nfs

Denning runs a few diskless nfs clients via pxe etc, unfortunatly nfs dosn't work very well, and i don't know why.

• The kernel used nfs v3 over tcp
• the mount works on my laptop (manual mounting)
• dosn't work on the spaces "windows" laptop (when netbooting)
• dosn't work on new colin (?) (when netbooting)
• i386 seems to work (?)
• but i386 has a newer kernel...

linkdump:

• https://lists.gnu.org/archive/html/ltib/2010-08/msg00103.html
• https://www.kernel.org/doc/Documentation/filesystems/nfs/nfsroot.txt

todo

• Try other machines incase it's a wierd nic driver bug
• Try more i386 vs. amd64.
• Upgrade kernel on the amd64 diskless image

Ansible procedures

using Ansible with a Rasbperry Pi

dd raspbian image (use the 02-09 one to avoid usb issues)
boot pi
watch dhcp logs on boole
ssh pi@ip
passwd: raspberry

sudo raspi-config
update it
expand filesystem
change password
boot to console
advanced options -> hostname

cd /etc/network
edit interfaces to get a static ip
reboot

on boole:

add hostname to fwd and rev. dns, don't forget to commit your changes.

log into denning with ssh keys forwarded

add hostname to /etc/ansible/hosts in both the [lhshosts] and [rpis]
sections, and [doorbot] if it's a doorbot, make the syslocation="something sensible"

then:

if it's a replacement for an old machine then:

ssh-keygen -R hostname
ssh-keygen -R hostname.lan.london.hackspace.org.uk
ssh-keygen -R ipv4 address (?)
ssh-keygen -R ipv6 address (?)

then:

cd /etc/ansible

install python-apt which ansible needs:

ansible -vvv -u pi -k -s -m command -a "apt-get -y install python-apt" "hostname"

Then run it

ansible-playbook -u pi -s -k -l "hostname" lhs/site.yml

The 2nd one will add our users, ssh keys, packages, etc etc.

notes:

not sure how resolv.conf gets setup, I thought having:

iface eth0 inet static
        [...]
        dns-nameservers 172.31.24.2
        dns-search lan.london.hackspace.org.uk

Would sort it, but maybe that dosn't and we got lucky from dhcp?

The dns stuff in /etc/network/interfaces appears to be bogus and resolv.conf needs to be
done manually, add to ansible.

Removing an admin

edit /etc/ansible/lhs/vars/defaults.yml, remove them from users, add them to disable_users, then re-run ansible.

Ansible Troubleshooting

problem, ansible dies in the snmp config cos it can't find a default ipv4 address.

fix: make sure the machine has an ipv4 default route

problem, the sshfp stuff just has hostname. rather than hostname.lan.london.hackspace.org.uk.

fix: edit /etc/hosts on the effected machine so that both the long and short versions of the hostname are in there.