DaemonSet
A DaemonSet is a Kubernetes resource that ensures a copy of a Pod runs on all or specific nodes in a cluster.
Description
In the context of AWS and Kubernetes, a DaemonSet is crucial for managing and deploying background tasks and services that need to operate across all nodes in a cluster. When a DaemonSet is created, Kubernetes automatically schedules a Pod on each node that matches the specified node selector, ensuring that essential services such as monitoring, logging, and resource management are consistently available. For instance, a DaemonSet can be used to deploy a logging agent like Fluentd or a monitoring agent like Prometheus Node Exporter on every node, facilitating the collection of logs or metrics regardless of where the application Pod is running. This is particularly important in cloud environments like AWS, where applications are often distributed across multiple nodes in an Elastic Kubernetes Service (EKS). By utilizing DaemonSets, organizations can ensure that pivotal system services are reliably available without the need to manually manage Pods on each node, thus simplifying operations and enhancing efficiency.
Examples
- Deploying Fluentd as a DaemonSet to aggregate logs from all nodes in an EKS cluster.
- Using a DaemonSet to run the Amazon EKS VPC CNI plugin on all worker nodes for networking capabilities.
Additional Information
- DaemonSets can be used with node affinity rules to control which nodes the Pods are deployed to.
- Updates to a DaemonSet can be managed seamlessly, minimizing disruption to running services.