Running

taken some from: https://www.digitalocean.com/community/tutorials/how-to-create-a-kubernetes-cluster-using-kubeadm-on-ubuntu-18-04

also a good one: https://blog.laputa.io/kubernetes-flannel-networking-6a1cb1f8ec7c

Step 1: install prereqs

install vagrant, virtualbox, and ansible

Step 2: set up network

since vagrant with virtual box failed to set up a private network I will do this manually by running the following:

# add a tap interface to connect all nodes in the network and name it tap0
# all the vms will create a bridge to this interface and thus be connected
# the name "tap0" is important since its used in the vagrantfile
sudo ip tuntap add name tap0 made tap
# set the ip that the host will use for the tap interface
sudo ip addr add 192.168.99.1 dev tap0
# put the tap interface up
sudo ip link set dev tap0 up
# configure your ip to route requests to this interface
sudo ip route add 192.168.99.0/24 dev tap0

Step 3: set up cluster

Open the Vagrantfile and set N to the number of worker nodes you want

Run vagrant up to set up the nodes and then vagrant provision to set up the kubernetes cluster. This uses the ansible playbooks to configure all the nodes.

Step 4: interracting with the cluster

To make things easier, you can set the node names in your /etc/hosts file. I added the following lines:

192.168.99.20 node0.test.com node0
192.168.99.21 node1.test.com node1

You can run kubectl by sshing into the master (ssh ubuntu@node0) or you can run it on the host machine by copying the kubernetes config file and putting it in a readable location.

Run scp ubuntu@node0:/home/ubuntu/.kube/config . to copy the config to your current directory and then run export KUBECONFIG="$(pwd)/config" so kubectl knows to operate on this config.

Alternatively, you can just place the config file in your ~/.kube/ directory

Run kubectl get nodes to see that all your nodes are ready to roll

Step 5: add persistent volume claim

To do this I added the following line to /etc/exports:

/home/kkrausse/projects/vag/shared *(rw,fsid=0,async,no_subtree_check,no_auth_nlm,insecure,no_root_squash)

where /home/kkrausse/projects/vag/shared was the directory to mount for the nfs volume then ran sudo exportfs -a to update the nfs server that was already running

Then did kubectl apply -f pv.yml to put that on there

vocabulary

when I say "host machine," I am talking about the machine that vagrant and and virtual box are installed on. This is opposed to "guest machine" which is one that is virtual.

TODO

change the workers' ips so they are in the kubernetes CIDR (10.244.0.0/16 in this case). This should solve the issue about pods on other nodes not being found without having to change the default kubelet args in /etc/default/kubelet
- nvm this is wrong. Only the pod-cider from within the node be a sub-cidr of the cluster-wide one. doesnt matter with the node ip

celine168/kube-dev-env