My Raspberry PI based IOT stack, introduced in an [earlier article](https://admantium.com/blog/iot01_installing_iot_stack/), is productive and online for more than one year. It’s time to make a full upgrade of the operating system, the Docker containers, and all associated configurations.
OpenShift is platform for running containerized application workloads. It’s been in development for over 10 years, and the recent version supports Kubernetes as the default orchestration mode.
The Google Kubernetes Engine provides a managed Kubernetes environment. Like its counterpart in AWS, it is also deeply integrated into the Google cloud, and allows to use other abstractions.
There are several options to roll your own Kubernetes cluster. In addition to provisioning on managed infrastructure, you can also create a managed cluster that is integrated with a particular cloud environment, enabling you to use other services and concepts from the cloud environment.
Kubeadm is a Kubernetes distribution that provides all customization options that you can think of: container runtime, container network interface, cluster storage and ingress. You can configure all these aspects of your cluster but have to understand the individual options and their setup as well. For a complete overview about this remarkable distribution, see my [previous article](https://admantium.com/blog/kube08_kubeadm/).
Kops is a Kubernetes distribution that installs a Kubernetes cluster on cloud providers. Fully supported are AWS und GCE, and beta support exists for Digital Ocean, Hetzner and Open Stack.
The Kubespray distribution brings the power of Ansible for configuration, setup, and maintenance of a Kubernetes cluster. Starting from an inventory file, you define which nodes are part of the cluster and which role they should play. Then, additional configuration files fine-tune the settings of the various Kubernetes components. By applying the playbook - Ansible jargon for the installation/setup scripts that consume your configuration - the desired state is manifested on the target server. Using Kubespray means to manifest your cluster as true Infrastructure as code: All subsequent runs lead to the very same desired state.
Kubeadm is a Kubernetes distribution that provides all customization options that you can think of: container runtime, container network interface, cluster storage and ingress. You can configure all these aspects of your cluster, but have to understand the individual options and their setup as well. For a complete overview about this remarkable distribution, see my [previous article](https://admantium.com/blog/kube08_kubeadm/).
There are several Kubernetes distributions. A remarkable simple on is K3S, a lightweight distribution with a small CPU/memory footprint that can run on anything from cloud vm, bare metal to IOT edge devices, including a raspberry Pi. This is achieved because K3S comes bundled as a single binary with all K3S components and using an embedded SQL lite database. Read more about K3S in my [previous article](https://admantium.com/blog/kube06_k3s_distribution/).
The final Kubernetes distribution to look at is called kops, a CLI tool for configuring, setup and maintaining a Kubernetes cluster inside cloud environments. At the time of writing, only amazon AWS is fully supported, and this will be the focus of this article. With kops, you ultimately define all configuration options in a detailed YAML file, giving you a single source for your complete cluster. This article explains everything you need to know for getting started with kops.
