A Kubernetes concept – DaemonSet

A Kubernetes resource that we have now used (through Helm) is DaemonSet. This resource is a wrapper around pods very similar to ReplicaSet, but with the purpose of running a pod on every node in a cluster. When we installed Prometheus using Helm, it created a DaemonSet to run node-collector on each node within the Kubernetes cluster.

There are two common patterns for running software in a support role with your application: the first is using the side-car pattern, and the second is using a DaemonSet. A side-car is when you include a container within your pod whose sole purpose is to run alongside the primary application and provide some supporting, but external, role. An example of a useful side-car might be a cache, or a proxy service of some form. Running a side-car application obviously increases the resources needed for a pod, and if the number of pods is relatively low or they are sparse compared to the size of a cluster, this would be the most efficient...