Which of the below mentioned options is the best possible solution in this case?
The user should create a separate IAM user for each employee and provide access to them as per the policy
The user should create an IAM role and attach STS with the role. The user should attach that role to the EC2 instance and setup AWS authentication on that server
The user should create IAM groups as per the organization’s departments and add each user to the group for better access control
Attach an IAM role with the organization’s authentication service to authorize each user for various AWS services
Explanations:
Managing individual IAM users for 1000+ employees is cumbersome and does not scale well. It would require maintaining separate credentials and permissions for each user, leading to administrative overhead.
IAM roles with STS (Security Token Service) are useful for temporary access but not ideal for managing access for a large number of employees directly. Attaching the role to EC2 instances is not a scalable solution for managing employee access.
Creating IAM groups based on departments is a scalable approach to manage user access. It simplifies permissions by attaching policies to groups rather than individuals, making it easier to manage access control across large numbers of users.
Attaching an IAM role to an organization’s authentication service (like SSO or Active Directory) may help in some cases, but it is not a comprehensive solution for controlling access to AWS resources for all employees. It lacks granularity compared to using IAM groups.