Cloud IAM Basics

What is IAM in cloud computing? Explain the concepts of users, roles, and policies.

Cloudbeginner

// interview question

What is IAM in cloud computing? Explain the concepts of users, roles, and policies.

Sample answer

IAM (Identity and Access Management) controls who can access cloud resources and what they can do. Users are individual identities (people or services). Roles are sets of permissions that can be assumed temporarily. Policies are JSON documents that define what actions are allowed or denied on which resources. The principle of least privilege means giving only the minimum permissions needed.

Why this matters

IAM is the security foundation of cloud infrastructure. Misconfigured IAM is one of the top causes of cloud breaches. DevOps engineers must understand IAM to set up secure CI/CD pipelines, manage service accounts, and follow security best practices.

Code examples

Example AWS IAM Policy

json

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "s3:GetObject",
        "s3:PutObject"
      ],
      "Resource": "arn:aws:s3:::my-bucket/*"
    }
  ]
}

AWS CLI IAM commands

bash

# List IAM users
aws iam list-users

# List attached policies for a user
aws iam list-attached-user-policies --user-name devops

# Get current identity
aws sts get-caller-identity