* Add system:coredns ClusterRole and binding * Annotate CoreDNS for Prometheus metrics scraping * Remove kube-dns deployment, service, & service account * https://github.com/poseidon/terraform-render-bootkube/pull/71 * https://kubernetes.io/blog/2018/06/27/kubernetes-1.11-release-announcement/
4.9 KiB
Hardware
Typhoon ensures certain networking hardware integrates well with bare-metal Kubernetes.
Ubiquiti
Ubiquiti EdgeRouters work well with bare-metal Kubernetes clusters. Knowledge about how to setup an EdgeRouter and use the CLI is required.
PXE
Ubiquiti EdgeRouters can provide a PXE-enabled network boot environment for client machines.
ISC DHCP
Add a subnet parameter to the LAN DHCP server to include an ISC DHCP config file.
configure
show service dhcp-server shared-network-name NAME subnet SUBNET
set service dhcp-server shared-network-name NAME subnet SUBNET subnet-parameters "include "/config/scripts/ipxe.conf";"
commit-confirm
Switch to root (i.e. sudo -i
) and write the ISC DHCP config /config/scripts/ipxe.conf
. iPXE client machines will chainload to matchbox.example.com
, while non-iPXE clients will chainload to undionly.kpxe
(requires TFTP to be enabled).
allow bootp;
allow booting;
next-server ADD_ROUTER_IP_HERE;
if exists user-class and option user-class = "iPXE" {
filename "http://matchbox.example.com/boot.ipxe";
} else {
filename "undionly.kpxe";
}
TFTP
Use dnsmasq
as a TFTP server to serve undionly.kpxe.
sudo -i
mkdir /var/lib/tftpboot
cd /var/lib/tftpboot
curl http://boot.ipxe.org/undionly.kpxe -o undionly.kpxe
Add dnsmasq
command line options to enable the TFTP file server.
configure
show service dns forwarding
set service dns forwarding options enable-tftp
set service dns forwarding options tftp-root=/var/lib/tftpboot
commit-confirm
!!! warning
After firmware upgrades, the /var/lib/tftpboot
directory will not exist and dnsmasq will not start properly. Repeat this process following an upgrade.
DHCP
Assign static IPs to clients with known MAC addresses. This is called a static mapping by EdgeOS. Configure the router with the commands based on region inventory.
configure
show service dhcp-server shared-network
set service dhcp-server shared-network-name LAN subnet SUBNET static-mapping NAME mac-address MACADDR
set service dhcp-server shared-network-name LAN subnet SUBNET static-mapping NAME ip-address 10.0.0.20
DNS
Assign DNS A records to nodes as options to dnsmasq
.
configure
set service dns forwarding options host-record=node.example.com,10.0.0.20
Restart dnsmasq
.
sudo /etc/init.d/dnsmasq restart
Configure queries for *.svc.cluster.local
to be forwarded to the Kubernetes coredns
service IP to allow hosts to resolve cluster-local Kubernetes names.
configure
show service dns forwarding
set service dns forwarding options server=/svc.cluster.local/10.3.0.10
commit-confirm
Kubernetes Services
Add static routes for the Kubernetes IPv4 service range to Kubernetes node(s) so hosts can route to Kubernetes services (default: 10.3.0.0/16).
configure
show protocols static route
set protocols static route 10.3.0.0/16 next-hop NODE_IP
...
commit-confirm
Port Forwarding
Expose the Ingress Controller by adding port-forward
rules that DNAT a port on the router's WAN interface to an internal IP and port. By convention, a public Ingress controller is assigned a fixed service IP (e.g. 10.3.0.12).
configure
set port-forward wan-interface eth0
set port-forward lan-interface eth1
set port-forward auto-firewall enable
set port-forward hairpin-nat enable
set port-forward rule 1 description 'ingress http'
set port-forward rule 1 forward-to address 10.3.0.12
set port-forward rule 1 forward-to port 80
set port-forward rule 1 original-port 80
set port-forward rule 1 protocol tcp_udp
set port-forward rule 2 description 'ingress https'
set port-forward rule 2 forward-to address 10.3.0.12
set port-forward rule 2 forward-to port 443
set port-forward rule 2 original-port 443
set port-forward rule 2 protocol tcp_udp
commit-confirm
Web UI
The web UI is often accessible from the LAN on ports 80/443 by default. Edit the ports to 8080 and 4443 to avoid a conflict.
configure
show service gui
set service gui http-port 8080
set service gui https-port 4443
commit-confirm
BGP
Add the EdgeRouter as a global BGP peer for nodes in a Kubernetes cluster (requires Calico). Neighbors will exchange podCIDR
routes and individual pods will become routable on the LAN.
Configure node(s) as BGP neighbors.
show protocols bgp 1
set protocols bgp 1 parameters router-id LAN_IP
set protocols bgp 1 neighbor NODE1_IP remote-as 64512
set protocols bgp 1 neighbor NODE2_IP remote-as 64512
set protocols bgp 1 neighbor NODE3_IP remote-as 64512
View the neighbors and exchanged routes.
show ip bgp neighbors
show ip route bgp
Be sure to register the peer by creating a Calico BGPPeer
CRD with kubectl apply
.
apiVersion: crd.projectcalico.org/v1
kind: BGPPeer
metadata:
name: NAME
spec:
peerIP: LAN_IP
asNumber: 64512