Kubernetes Template: Upgrade all Software in a BigchainDB Node¶
A highly-available Kubernetes cluster requires at least five virtual machines (three for the master and two for your app’s containers). Therefore we don’t recommend using Kubernetes to run a BigchainDB node if that’s the only thing the Kubernetes cluster will be running. Instead, see our Simple Deployment Template. If your organization already has a big Kubernetes cluster running many containers, and your organization has people who know Kubernetes, then this Kubernetes deployment template might be helpful.
This page outlines how to upgrade all the software associated with a BigchainDB node running on Kubernetes, including host operating systems, Docker, Kubernetes, and BigchainDB-related software.
Upgrade Host OS, Docker and Kubernetes¶
Azure Container Service (ACS). On Dec. 15, 2016, a Microsoft employee wrote: “In the coming months we [the Azure Kubernetes team] will be building managed updates in the ACS service.” At the time of writing, managed updates were not yet available, but you should check the latest ACS documentation to see what’s available now. Also at the time of writing, ACS only supported Ubuntu as the host (master and agent) operating system. You can upgrade Ubuntu and Docker on Azure by SSHing into each of the hosts, as documented on another page.
In general, you can SSH to each host in your Kubernetes Cluster to update the OS and Docker.
Once you are in an SSH session with a host,
docker info command is a handy way to detemine the
host OS (including version) and the Docker version.
When you want to upgrade the software on a Kubernetes node, you should “drain” the node first, i.e. tell Kubernetes to gracefully terminate all pods on the node and mark it as unscheduleable (so no new pods get put on the node during its downtime).
kubectl drain $NODENAME
There are more details in the Kubernetes docs, including instructions to make the node scheduleable again.
To manually upgrade the host OS, see the docs for that OS.
To manually upgrade Docker, see the Docker docs.
To manually upgrade all Kubernetes software in your Kubernetes cluster, see the Kubernetes docs.