Token Controller

What

What is the Token Controller?

The Token Controller is a component within the Kubernetes controller manager responsible for managing the lifecycle of tokens for service accounts. It ensures that service accounts have the necessary tokens for authentication to the Kubernetes API and handles the creation, rotation, and deletion of these tokens.

What types of tokens does the Token Controller manage?

The Token Controller primarily manages:

Service Account Tokens: Used by pods to authenticate to the Kubernetes API.
Bootstrap Tokens: Used for cluster bootstrapping and node joining processes.

Why

Why is the Token Controller important?

Automation: Automates the management of service account tokens, reducing the administrative burden.
Security: Ensures that tokens are rotated and managed securely, mitigating the risk of token compromise.
Consistency: Guarantees that all service accounts have valid tokens, ensuring seamless authentication for pods.

How

How does the Token Controller work?

Token Creation: When a service account is created, the Token Controller generates a corresponding token and stores it in a Kubernetes secret.
Token Rotation: Periodically, the Token Controller rotates tokens to ensure they are refreshed and reduce the risk of long-lived token compromise.
Token Deletion: When a service account is deleted, the Token Controller ensures that the associated token is also deleted, cleaning up any unnecessary credentials.

How does the Token Controller interact with secrets?

The Token Controller creates Kubernetes secrets that contain the service account tokens. These secrets are automatically mounted into pods that use the corresponding service accounts. The tokens are stored securely within these secrets and are accessible by the pods for authenticating to the Kubernetes API.

How do you configure service account tokens?

Custom Expiry: You can configure custom expiry durations for tokens to balance security and usability.

Token Volume Projection: Use projected volume types to mount tokens with specific configurations into pods.

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
spec:
  serviceAccountName: my-service-account
  containers:
  - name: my-container
    image: my-image
  volumes:
  - name: token
    projected:
      sources:
      - serviceAccountToken:
          path: token
          expirationSeconds: 3600

When

When does the Token Controller create a new token?

The Token Controller creates a new token whenever a new service account is created or when token rotation is required based on the configured policies.

When might you need to manually manage tokens?

Custom Token Requirements: For specific security policies or compliance reasons, you may need to create and manage tokens manually.
Troubleshooting: To address issues related to token expiration, invalidation, or access problems.
Security Audits: To review and rotate tokens as part of regular security audits.

#Kubernetes #TokenController #ServiceAccount #Authentication #Security #DevOps #ClusterManagement #ContainerSecurity