Using koris on bare metal

This is a short guide which is intended if you intend to install koris on Bare Metal machine or Virtual Machines which do not use the official koris image.

First you need to make sure you can SSH to all the machines and you have a loadbalancer configured with a domain name.

Start with configuring the load balancer listener group to have 1 member pointing to you master. You need to direct traffic from coming to your domain on port 6443 to port 6443 of the first master’s IP address.

Then you need to write a koris.env file and copy it to the first master in /etc/kubernetes/koris.env

Parameter	Explanation
BOOTSTRAP_NODES	install kubernetes componetes on the nodes and master if 1
POD_SUBNET	K8S pod subnet to be used by the network plugin
POD_NETWORK	CALICO or FLANNEL others aren’t supported
LOAD_BALANCER_PORT	6443 only change this if you feel adventerous
MASTER_IPS	a list of all masters IP addresses
MASTERS	a list of all masters short hosnames
LOAD_BALANCER_IP	the IP address of the load balancer. DON’T set if you have LOAD_BALANCER_DNS
LOAD_BALANCER_DNS	the DNS name of the load balancer. DON’T set if you have LOAD_BALANCER_IP
BOOTSTRAP_TOKEN	set this for initial value of the bootstrap token or leave empty.
OPENSTACK	NEVER change this on baremetal, leave this 0
SSH_USER	the name of the user that SSH on all machines, must be able to sudo
K8SNODES	the list of worker nodes to join the cluster

Prior configuration before you run the script:

Kuberentes and etcd are especially sensitive to this. Hence, you must make sure that the command hostname on all your hosts returns only the short name, e.g:

$ hostname
myhost

# wrong !
myhost.noris.de

If your /etc/hosts file has entries with FQDN name, they should be removed too. You should remove all search domain from resolv.conf! For example:

sed -i 's/'$(hostname -s)'.noriscloud //g' /etc/hosts
sed -i 's/^search/#search/g' /etc/resolv.conf

Finally, make sure all swaps and firewall are disabled on all hosts!

Running the script:

First, create a correct koris.env file and copy it to the first master where you intead to run the script. You can do this with ansible or directly with scp. The file must be saved in /etc/kuberentes/koris.env.

Then, obtain the bootstrap script either from git clone, curl or any other method. If you downloaded it to your work machine, copy it over to the first master (the same machine where /etc/kubernetes/koris.env is found). Then run the script as root:

# bash bootstrap-k8s-master-ubuntu-16.04.sh

The script will intall all dependencies on all node if you instructed it to do so. This takes a little while, dependending on the number of masters nodes and how fast is the internet connection is.