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Setup DNS for your RKE2 Cluster

Your RKE2/Rancher nodes need to be able to find each other by name. This means DNS.

I generally like to install and configure the Avahi Daemon so that things can just find each other automagically but this doesn't work for RKE2. We need another solution.

Unless your solution involves dynamic DNS registration (probably not), now is the time to think about IP allocations. You can either:

  • Use Static IPs
    • Should be in the same subnet as the rest of the LAN you're connecting to, unless you are deliberately segregating things (e.g. in a seperate VLAN)
    • Should be excluded from the network's DHCP pool to avoid conflicts
  • Use DHCP and/or IPv6 Auto Configuration (my preference)
    • DHCP leases should be made static/persistant in your DHCP server. Not all (read: cheap/simple) DHCP servers (e.g. in home routers) suppport this.
    • TODO: IPv6 Auto Configuration IPs are generally not static. How do we deal with this?

LAN DNS Server: Microsoft Active Directory DNS Server​

If your network already has an Active Directory, you might as well use it's DNS server.

  • Create a new "Forward Lookup" zone (unless the zone you want to use already exists)
  • Create A or AAAA records for each VM's hostname pointing at the VM's IP.

LAN DNS Server: Zentyal​

I'm using my public FQDN (for a domain I own) as the domain that the RKE2 VMs are in. In future I might decide that this was a silly idea but for now, let's work with it.

My Zentyal server is authoritive for the internal only sub-domain "ad.ghanima.net". This is not the domain my RKE2 VMs.

I don't want to add "ghanima.net" to the Zentyal server. If I did I would either need to mirror all the public records in Zentyal or whenever Zentyal is asled about a record in this domain (e.g. mail.ghanima.net) it will authoritively respond that there is no such record.

What we will do is create sub-domains for each desired record:

  • rke1.ghanima.net
  • rke2.ghanima.net
  • rke3.ghanima.net

Each domain will have only a "Domain IP Address" (in Zentyal terminology) set.

  • From the Zentyal Control Panel, click DNS from the left side menu
  • Under Domains click Add New
  • Enter the domain name and click Add
  • Click the cog in the Domain IP Addresses column next to the domain just created.
  • Click Add New
  • Enter the IP address of the RKE2 VM and click Add
  • Repeat until you have created domains for each RKE2 VM
  • Click the Save Changes button it the top right corner of the page

LAN DNS Server: Samba 4 (internal or bind)​

TODO

LAN Router: Mikrotik​

/ip dns static
add address=172.30.1.94 name=rke1.ghanima.net ttl=1h
add address=172.30.1.95 name=rke2.ghanima.net ttl=1h
add address=172.30.1.93 name=rke3.ghanima.net ttl=1h

LAN Router: opnSense​

TODO

LAN Router: pfSense​

TODO

If all else fails: hosts file entries​

TODO