Pikube Cluster Cloud Init Generator

This is a set of python functions and some other stuff to allow you to generate cloud init files for a pi kube cluster. These can then be flashed using the hypriot flash utility to build a pi cluster

Requirements

There's a few things that require this to work out of the box:

• The hypriot flash utility (see references)
• A router that will allow you to discover the other Pi nodes via DNS. I use a travel router with openwrt. This enables the pis to look each other up by name. You could also do this with static entries.
• Some SD cards. Preferably class 10 or better
• Some Pis. I use 5. It's up to you

Usage

• Create a cluster_config.yaml based on the example in the file. You can create multiple users and set wifi/lan info here
• If you delete the token field, one will be randomly generated for you
• Make sure you have all the packages installed in requirements.txt
• Run ./gen_configs.py
• Run ./flash.sh <cluster prefix>, this will start a flash of the SD Cards (requires hypriot flash utility from references)
• Start up the first node right away. This one takes the longest.
• Then start the other nodes and they will join the cluster. This can take a while.

Note: The kubeconfig to access the cluster will be in /etc/kubernetes/admin.conf. You will need this to use kubectl

Other Notes

Networking

I use weavenet because it's the easiest to get working with kubeadm. Right now this tool doesn't support anything else.

Also, I am using some specific address ranges inside the cidr that you specify. I may add a way to change these, but until then deal with these:

• 1-x For the nodes
• 254 - gateway
• 200 - The master. I figured you wouldn't have more than 199 nodes using this

Self-Hosted

I really like the self hosted kubernetes model. Enable that in the kubeadm section of cluster_config.yaml

Helm

If you want to install a tiller for helm, use this

helm init --tiller-image timotto/rpi-tiller:latest --service-account tiller

flash.sh

You can use the flash.sh to flash a single node's card. Just use ./flash.sh <prefix>-nodeX.yaml

If you want to no overwrite once you have a token, just put the token in the cluster config. This will overwrite, but with the same token so your kube cluster will continue to work.

Useful commands

Find the bat0 link-local address:

ip addr show bat0 | grep -Po 'inet \K[\d.]+'

Find the mesh IPs

avahi-browse --terminate --ignore-local --verbose -p  -a | grep bat | grep IPv4

Decode a file out of an existing config for debugging

decode_file.sh <prefix>-master.yaml <filename>

## References

This is all utilizing a ton of work by hypriot.  Thanks!

https://blog.hypriot.com/post/cloud-init-cloud-on-hypriot-x64/
https://github.com/hypriot/flash

## Known Issues

Weave install command doesn't seem to work with 1.9.4. I have pinned to 1.8.9