How to manage multiple roles which has various EKS permissions using RBAC in EKS. Also we will need combination for EKS Cluster Roles and IAM Roles for the same.

Managing multiple roles with various permissions in an Amazon EKS cluster using Role-Based Access Control (RBAC) involves a combination of Kubernetes ClusterRoles and ClusterRoleBindings for EKS-specific permissions and AWS IAM roles and policies for AWS resource-level permissions. Here are the steps to achieve this:

1. Define Kubernetes ClusterRoles: First, you'll define Kubernetes ClusterRoles for various roles you want to create. These ClusterRoles represent the permissions you want to grant within the Kubernetes cluster. You can create these ClusterRoles using YAML manifests or kubectl.

For example, you might create ClusterRoles for roles like developer, admin, and viewer, each with different sets of permissions within the cluster.

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: developer-role
rules:
- apiGroups: [""]
  resources: ["pods", "services"]
  verbs: ["get", "list", "create", "update", "delete"]
# Add more rules as needed

2. Define Kubernetes ClusterRoleBindings: Next, create ClusterRoleBindings that associate IAM roles or users with the ClusterRoles defined earlier. These ClusterRoleBindings determine which IAM entities can assume specific roles within the Kubernetes cluster.

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: developer-binding
subjects:
- kind: User
  name: <IAM-username>
roleRef:
  kind: ClusterRole
  name: developer-role
  apiGroup: rbac.authorization.k8s.io

Replace <IAM-username> with the actual IAM user or role name you want to associate with the ClusterRole.

3. AWS IAM Roles and Policies: To manage AWS resource-level permissions, you will create IAM roles and attach policies to them. These IAM roles will be assumed by your EKS worker nodes or other AWS services that need access to AWS resources. Create IAM roles and attach policies that grant permissions to perform AWS actions. You can use the AWS Management Console, AWS CLI, or AWS CloudFormation to define these roles and policies.

4. IAM Role for Service Accounts (IRSA): If you need to associate IAM roles with specific Kubernetes Service Accounts, you can use IAM Role for Service Accounts (IRSA). This allows you to bind AWS IAM roles directly to Kubernetes Service Accounts, providing AWS permissions directly to pods running in the EKS cluster.

5. AWS Authenticator Configuration: Ensure that your EKS cluster is configured to use the AWS authenticator for Kubernetes. This is necessary for IAM roles to be properly mapped to Kubernetes users.

6. Testing and Verification: Test your setup by deploying pods and services that use the various roles you've defined. Ensure that the permissions are correctly enforced.

7. Logging and Monitoring: Implement logging and monitoring to keep track of activities within your EKS cluster. AWS CloudWatch Logs and Amazon CloudWatch Metrics can be valuable for this purpose.

Remember that managing permissions and access control in EKS can be complex, and it's crucial to follow security best practices and regularly audit your permissions to ensure they are aligned with your requirements and policies. Additionally, always follow the principle of least privilege to minimize the risk of security breaches.