Kubernetes Components

Kubernetes Components

Deployments

• A deployment is a way to manage a set of replica pods
• It ensures a specified number of replicas are running at any given time
• Deployments can be scaled up or down, and rolled back to a previous version if needed
• Key features:
  • Rolling updates and rollbacks
  • Self-healing: replacing failed pods
  • Scaling: increasing or decreasing replicas

Pods

• The basic execution unit in Kubernetes
• A pod represents a single instance of a running application
• Pods can contain one or more containers
• Key features:
  • Ephemeral: pods can be created, scaled, and terminated dynamically
  • Co-location: pods can share resources and communicate with each other
  • Management: pods can be managed as a single unit

Services

• A logical abstraction over a set of pods
• Provides a network identity and load balancing for accessing pods
• Services can be exposed to the outside world or kept internal
• Key features:
  • Service discovery: automatic registration and discovery of services
  • Load balancing: distributing traffic across multiple pods
  • Cluster-IP: assigning a fixed IP address to a service

Persistent Volumes

• A resource that provides persistent storage for data
• Decouples storage from pods and deployments
• Persistent volumes can be provisioned and managed dynamically
• Key features:
  • Persistent data: data remains even if pods are deleted or recreated
  • Dynamic provisioning: storage can be allocated and deallocated as needed
  • Access modes: read-only, read-write, and others

Kubernetes Security

• Built-in security features:
  • Network policies: controlling traffic between pods and services
  • Secret management: storing and managing sensitive data
  • Role-based access control (RBAC): controlling user and service access
• Key concepts:
  • Authentication: verifying identities
  • Authorization: controlling access to resources
  • Admission control: enforcing security policies at runtime

Kubernetes Components

Deployments

• Manage a set of replica pods, ensuring a specified number of replicas run at any time
• Allow scaling up or down and rolling back to a previous version if needed
• Feature rolling updates and rollbacks, self-healing by replacing failed pods, and scaling

Pods

• Basic execution unit in Kubernetes, representing a single instance of a running application
• Contain one or more containers and are ephemeral, scalable, and manageable as a single unit
• Can be created, scaled, and terminated dynamically and share resources and communicate with each other

Services

• Logical abstraction over a set of pods, providing a network identity and load balancing
• Can be exposed to the outside world or kept internal, featuring service discovery and load balancing
• Assign a fixed IP address to a service and allow access to multiple pods

Persistent Volumes

• Resource providing persistent storage for data, decoupling storage from pods and deployments
• Data remains even if pods are deleted or recreated, with dynamic provisioning and access modes
• Storage can be allocated and deallocated as needed, with read-only, read-write, and other access modes

Kubernetes Security

• Built-in security features include network policies, secret management, and role-based access control (RBAC)
• Control traffic between pods and services, store and manage sensitive data, and control user and service access
• Key concepts include authentication, authorization, and admission control, ensuring security at runtime