Description: Kubernetes DaemonSet is an API object for workload that ensures that all (or some) nodes in a Kubernetes cluster run a copy of a Pod. This is particularly useful for applications that need to run on every node, such as monitoring agents, logging services, or any other type of service that must be present on all nodes to function correctly. A DaemonSet allows system administrators to efficiently manage the deployment of these Pods, ensuring they remain running and are automatically updated when changes are made to the configuration or container image. Additionally, DaemonSets can be configured to run on specific nodes or to exclude nodes from running, providing flexibility in resource management and workload distribution. This feature is essential for maintaining the consistency and availability of critical services in a microservices environment, where resilience and scalability are key.
History: Kubernetes was released by Google in 2014 as a container orchestration system, and DaemonSet was introduced as one of its key features from the outset. As Kubernetes gained popularity, the functionality of DaemonSet became established as an essential tool for managing workloads in clusters, allowing users to efficiently deploy services that require presence on every node.
Uses: DaemonSets are commonly used to deploy infrastructure services, such as monitoring agents, logging services, and network management tools. They are also useful for running tasks that need to be performed on every node, such as collecting metrics or managing node-specific configurations.
Examples: A practical example of a DaemonSet is the deployment of Fluentd, a log collection agent that runs on every node to gather and send logs to a centralized system. Another example is using a DaemonSet to deploy a monitoring agent like Prometheus Node Exporter, which collects operating system metrics from each node.
