my-docs/kubernetes/workloads/deployment.md

1. Deployment with Resource Limits and Horizontal Pod Autoscaler

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  namespace: my-ns
  labels:
    app.kubernetes.io/name: myapp
    app.kubernetes.io/env: development
spec:
  replicas: 5
  selector:
    matchLabels:
      app.kubernetes.io/name: myapp
      app.kubernetes.io/env: development
  template:
    metadata:
      labels:
        app.kubernetes.io/name: myapp
        app.kubernetes.io/env: development
    spec:
      containers:
      - name: nginx
        image: nginx # change image and apply again
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"
          requests:
            memory: "64Mi"
            cpu: "250m"
        ports:
        - containerPort: 80

• apiVersion: apps/v1: Specifies the API version.
• kind: Deployment: Defines the object as a Deployment.
• metadata: Provides metadata for the Deployment.
  • name: The name of the Deployment (myapp).
  • namespace: The namespace where the Deployment will be created (my-ns).
  • labels: Key-value pairs to categorize the Deployment.
• spec: Describes the desired state.
  • replicas: Number of pod replicas (5).
  • selector: Identifies the pods managed by this Deployment.
  • template: The pod template used by the Deployment.
    • metadata: Metadata for the pod template.
    • spec: Describes the pod specification.
      • containers: Defines the containers within the pod.
        • name: The name of the container (nginx).
        • image: The container image (nginx).
        • resources: Resource limits and requests.
          • limits: Maximum resources (128Mi memory, 500m CPU).
          • requests: Minimum resources (64Mi memory, 250m CPU).
        • ports: Container ports (80).

2. Deployment with Rolling Update Strategy

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: my-name
  labels:
    name: my-name
spec:
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      labels:
        name: my-name
    spec:
      containers:
      - image: ipedrazas/docmock
        name: my-name
        resources:
          requests:
            cpu: "20m"
            memory: "55M"
        livenessProbe:
          httpGet:
            path: /_status/healthz
            port: 5000
          initialDelaySeconds: 90
          timeoutSeconds: 10
        readinessProbe:
          httpGet:
            path: /_status/healthz
            port: 5000
          initialDelaySeconds: 30
          timeoutSeconds: 10
        env:
        - name: ENVVARNAME
          value: ENVVARVALUE       
        ports:
        - containerPort: 5000
          name: my-name
        volumeMounts:
        - mountPath: /data
          name: data
      volumes:
        - name: data
          emptyDir: {}
      restartPolicy: Always
      imagePullPolicy: Always

• apiVersion: extensions/v1beta1: Specifies the API version.
• kind: Deployment: Defines the object as a Deployment.
• metadata: Provides metadata for the Deployment.
  • name: The name of the Deployment (my-name).
  • labels: Key-value pairs to categorize the Deployment.
• spec: Describes the desired state.
  • strategy: Rolling update strategy.
    • rollingUpdate: Defines the update strategy.
      • maxSurge: Maximum number of additional pods (1).
      • maxUnavailable: Maximum number of unavailable pods (1).
    • type: The type of update strategy (RollingUpdate).
  • template: The pod template used by the Deployment.
    • metadata: Metadata for the pod template.
    • spec: Describes the pod specification.
      • containers: Defines the containers within the pod.
        • name: The name of the container (my-name).
        • image: The container image (ipedrazas/docmock).
        • resources: Resource requests.
          • requests: Minimum resources (20m CPU, 55M memory).
        • livenessProbe: Health check for the container.
          • httpGet: HTTP GET request for the probe.
            • path: The path to check (/_status/healthz).
            • port: The port to check (5000).
          • initialDelaySeconds: Initial delay before the probe starts (90 seconds).
          • timeoutSeconds: Timeout for the probe (10 seconds).
        • readinessProbe: Readiness check for the container.
          • httpGet: HTTP GET request for the probe.
            • path: The path to check (/_status/healthz).
            • port: The port to check (5000).
          • initialDelaySeconds: Initial delay before the probe starts (30 seconds).
          • timeoutSeconds: Timeout for the probe (10 seconds).
        • env: Environment variables for the container.
          • name: The name of the environment variable (ENVVARNAME).
          • value: The value of the environment variable (ENVVARVALUE).
        • ports: Container ports.
          • containerPort: The container port (5000).
          • name: The name of the port (my-name).
        • volumeMounts: Mounting volumes to the container.
          • mountPath: The path to mount the volume (/data).
          • name: The name of the volume (data).
      • volumes: Defines the volumes.
        • name: The name of the volume (data).
        • emptyDir: An empty directory volume.
      • restartPolicy: Restart policy for the container (Always).
      • imagePullPolicy: Image pull policy (Always).