How is the deployment and launch of containerized applications organized in Kubernetes?

Launching and deploying containerized applications in Kubernetes is done through manifest descriptions in YAML or JSON format, which describe the desired state of objects (Pods, Deployments, Services, etc.).

Main steps:

1. Create Deployment: describes which container to run, how, and how many replicas are needed.

2. Apply the manifest: using the command kubectl apply -f deployment.yaml, Kubernetes creates the necessary objects.

3. Kubernetes Scheduler distributes pods across available nodes in the cluster.

4. Kubelet on each node runs containers via a container runtime (e.g., containerd or Docker).

5. Ensure network interaction: through Service objects, Ingress, and network plugins.

Example of a simple Deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp-container
        image: myapp-image:latest
        ports:
        - containerPort: 80

After applying such a manifest, Kubernetes will ensure the launch of three container instances of your application, monitoring their state and restarting them if necessary.