Kubernetes YAML manifest structure¶

A Kubernetes YAML manifest is a configuration file used to define and manage Kubernetes resources. These files follow a standard structure containing four required top-level fields: apiVersion, kind, metadata, and spec.^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md]

Top-level Fields¶

The structure of a Kubernetes manifest is built upon the following four keys:

• apiVersion: Specifies the version of the Kubernetes API the resource belongs to^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md].
• kind: Indicates the type of Kubernetes object to be created (e.g., Pod, Service, Deployment, Ingress)^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md]¹.
• metadata: Stores data that helps uniquely identify the object, including its name and labels^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md].
• spec: Defines the desired state of the resource, effectively "the specification" for that object^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md].

Common Sections¶

Metadata¶

The metadata field is essential for organizing and identifying resources. It typically includes: * name: The unique identifier for the resource within a namespace^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md]. * labels: Key-value pairs attached to the object (e.g., app: foo)^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md]. Labels are used by selectors in other resources, such as a Service targeting a specific set of Pods^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md].

Spec¶

The spec section contains the actual configuration of the resource. Its content varies significantly depending on the kind: * For Pods: It lists the containers to be run, including the image name, ports, and resource requirements^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md]. * For Ingress: It defines rules, hostnames, and backend services, often nested within an ingressClassName^[400-devops__06-Kubernetes__devops-helm__helm-jenkins__TODO.md]². * For Services: It defines the type of service and the ports to expose.

Example: Pod Manifest¶

Below is an example of a Pod manifest illustrating the standard structure^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md]:

apiVersion: v1
kind: [Pod](<./pod.md>)
metadata:
  name: foo
  labels:
    app: foo
spec:
  containers:
    - name: foo
      image: mikehsu0618/foo
      ports:
        - containerPort: 8080

In this example: * The metadata.labels field allows other resources to select this Pod^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md]. * The spec.containers field configures the container image and the port (containerPort) it exposes^[400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md].

Related Concepts¶

• Kubernetes
• Pod
• Kubernetes Ingress
• [[Service (Kubernetes)]]

Sources¶

• 400-devops__06-Kubernetes__k8s-ithelp__Day6__README.md
• 400-devops__06-Kubernetes__devops-helm__helm-jenkins__TODO.md