How to add a new host (salt era)

This example will use einstein12 as a sample machine which before was known as ra15. Before you begin, you need to have ssh-agent forwarding enabled to automatically commit/push to the various repos involved.

Steps to perform:

Salt+DNS

All of this is done on our central salt master machine:

1. Create a set of ssh hostkeys, e.g. by running

   /srv/salt/bin/salt_add_ssh_hostkeys einstein12

   followed by running

   /srv/salt/bin/recreate_ssh_knownhosts

2. Add host under

   /srv/salt/hosts/hosts.d

   e.g. in this case

   /srv/salt/hosts/hosts.d/einstein.hosts

   e.g. in this case

   10.20.80.12 einstein12.atlas.local einstein12
   172.17.0.12 mgeinstein12.atlas.local mgeinstein12
   172.17.1.12 ipeinstein12.atlas.local ipeinstein12
   

3. Commit these changes and push upstream, e.g.

   git add einstein.hosts
   git commit -m "Add einstein12 to DNS" einstein.hosts
   git push

   The actual /etc/hosts will be auto-created via a git hook and this change will be also automatically propagated to condormaster via a hooked salt state.apply
4. Check if the new host is already part of the appropriate nodegroups (/srv/salt/master.d/nodegroups.conf) and if the appropriate states are defined as the machine will run a salt highstate upon first reboot. Changes to nodegroups.conf or salt's top.sls may require a reload/restart of the salt-master process.

DHCP+FAI

All of this is done on our FAI server

1. Add/change MAC address to IP mapping under /etc/dhcp. In this case ra15 was the progenitor of einstein12, hence the old entries for ra15 needed to be moved from {data,mgmt}/radio.part to {data,mgmt}/einstein.part.
2. Committing the changes will automatically trigger a DHCP server restart

   git commit -am "Rename ra15 to einstein12"

3. Check configuration under /srv/fai/config if it is suitable for the base installation. Usually, this involves checking if the appropriate classes are set (class/50-host-classes) and depending on hostname/classes files under disk_config/, package_config/ and ZFS/.
4. Tell FAI to install the machine upon next reboot by running

   /usr/local/bin/fai-boot-generic.sh -v einstein12

   Please note that you need to automatically log into our salt server for this to work, e.g. you need to have ssh-agent forwarding enabled.

-- CarstenAulbert - 26 Oct 2016