my-docs/kubernetes/workloads/daemonset.md

YAML File Breakdown

1. Node Exporter DaemonSet

This DaemonSet is configured to run a Node Exporter container on each node in the my-ns namespace.

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: my-ns
  labels:
    app: example
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: node-exporter
      app.kubernetes.io/env: development
      app.kubernetes.io/part-of: monitoring
  template:
    metadata:
      labels:
        app.kubernetes.io/name: node-exporter
        app.kubernetes.io/env: development
        app.kubernetes.io/part-of: monitoring
    spec:
      containers:
      - name: node-exporter
        image: prom/node-exporter

• apiVersion: apps/v1: Specifies the API version.
• kind: DaemonSet: Defines the object as a DaemonSet.
• metadata: Provides metadata for the DaemonSet.
  • name: The name of the DaemonSet (node-exporter).
  • namespace: The namespace where the DaemonSet will be created (my-ns).
  • labels: Key-value pairs to categorize the DaemonSet (app: example).
• spec: Describes the desired state.
  • selector: Identifies the pods managed by this DaemonSet.
    • matchLabels: Matches pods with specified labels.
      • app.kubernetes.io/name: node-exporter
      • app.kubernetes.io/env: development
      • app.kubernetes.io/part-of: monitoring
  • template: The pod template used by the DaemonSet.
    • metadata: Metadata for the pod template.
      • labels: Labels applied to the pods.
        • app.kubernetes.io/name: node-exporter
        • app.kubernetes.io/env: development
        • app.kubernetes.io/part-of: monitoring
    • spec: Describes the pod specification.
      • containers: Defines the containers within the pod.
        • name: The name of the container (node-exporter).
        • image: The container image (prom/node-exporter).

2. Example DaemonSet

This DaemonSet is configured to run an example container on each node.

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: example-daemonset
  labels:
    app: example
spec:
  selector:
    matchLabels:
      app: example
  template:
    metadata:
      labels:
        app: example
    spec:
      containers:
      - name: example-container
        image: nginx

• apiVersion: apps/v1: Specifies the API version.
• kind: DaemonSet: Defines the object as a DaemonSet.
• metadata: Provides metadata for the DaemonSet.
  • name: The name of the DaemonSet (example-daemonset).
  • labels: Key-value pairs to categorize the DaemonSet (app: example).
• spec: Describes the desired state.
  • selector: Identifies the pods managed by this DaemonSet.
    • matchLabels: Matches pods with the label app: example.
  • template: The pod template used by the DaemonSet.
    • metadata: Metadata for the pod template.
      • labels: Labels applied to the pods (app: example).
    • spec: Describes the pod specification.
      • containers: Defines the containers within the pod.
        • name: The name of the container (example-container).
        • image: The container image (nginx).