Microkube

A small tool to quickly bootstrap a kubernetes cluster against a local docker daemon

Motivation

Debugging 'Kubernetes Apps'

Traditionally, when debugging kubernetes applications locally, you'd use minikube. However, this quickly results in quite some overhead:

• Local directories are only accessible from the cluster if you set up NFS
• Service IPs are inaccessible, you have to manually use kubectl proxy or expose them on the minikube node
• Cluster DNS is hidden
• Local images have to be pushed to some registry which is nontrivial as unencrypted docker registries normally trigger Dockers Insecure registry logic

How it works

Microkube generates configuration and certificates and then starts kubernetes directly against a local docker daemon. At the moment it only supports Linux due to directly launching kube-proxy, but in theory Windows support should be possible at some point

Installation

Microkube can be installed either as a package or by building everthing manually, see below.

Dev Setup

• You need etcd, hyperkube and the default CNI plugins. The easiest way to get them is to use the microkube-deps repo and invoking ./build.sh. This will build kubernetes, so you'll require about 15 GB of free disk space
• If you want to run tests or run microkube from the repository, create a folder third_party in the repository root and copy all binaries there
• If you're only interested in running microkubed from the command line, you can also specify the folder with the binaries as -extra-bin-dir
• Running it requires pkexec from Polkit (for obtaining root for kube-proxy and kubelet) and conntrack + iptables for kube-proxy
• Unittests additionally require the openssl command line utility
• Regenerating the log parser requires ldetool
• To build everything, do make
• Try running ./microkubed -verbose

Packaging

Apart from Docker, you'll need kubernetes-hyperkube, etcd-server and cni-plugins. Deployment happens on Debian 9 while CI runs Ubuntu 14.04, so any deb-based Linux still supported by Docker should do. To build the package, simply do dpkg-buildpackage -us -uc -b. If everything works correctly, the packages should appear in the parent directory. The installation process will automatically create a service user and grant it the necessary privileges via sudoers, so in this case you don't need to worry about this. After installation, microkube can be started using sudo systemctl start microkubed.

License

Apache 2.0