I am looking to add a user in AWS. I have a group with supportUser policy.
The thing is, he can create users and change passwords.
With supportUser policy, he is not able to view any payment information, billing or anything regarding the account.
I am looking for a policy that would only allow him to create a EC2 container, S3 storage and a database. Nothing more. Is there a way to achieve this?
AWS gives you options to create your own fine-grained policies or you can simply use managed policies. Managed policies provide a gentler introduction because AWS has provided curated policies for you. Managed policies are also updated periodically to incorporate new function or new services, as relevant to each specific managed policy.
See AWS managed policies for job functions or, more generally, AWS managed policies.
The simplest managed policies for your use case are probably:
AmazonEC2FullAccess
AmazonRDSFullAccess
AmazonS3FullAccess
Important note: each of these policies grants the user significant permissions over all EC2, RDS, and S3 resources so you may find them too permissive for your use case.
If you want more control then write your own policies. Start at Policies and permissions in IAM. You can also copy/paste the contents of a managed policy and then edit it down to just the permissions you want, and constrained to the resources that you want (e.g. to specific, named S3 buckets).
So after reading through this: AWS IAM Role vs Group I'm not entirely sure what would be better for a group of users.
We're looking at implementing a group of users with least privileges, but doing it by giving them all a 'dev' role to assume, rather than a group.
This seems reasonable but what's the best practice here? What advantages do AWS User Groups have over Roles or vice versa?
IAM groups and roles, they both serve different purpose.
An IAM group is primarily a management convenience to manage the same set of permissions for a set of IAM users. Groups can be granted permissions using access control policies. This makes it easier to manage permissions for a collection of users, rather than having to manage permissions for each individual user.
IAM roles allow you to delegate access with defined permissions to trusted entities without having to share long-term access keys. You can use IAM roles to delegate access to IAM users managed within your account, to IAM users under a different AWS account, or to an AWS service such as EC2.
Please check out AWS IAM Faqs for more details.
Related to AWS:
I've been trying to search for an answer about the Users and Groups that I have created using IAM (AWS), how can I map those Groups with the Organization Unit(s)?
For example: I have a Group called 'Developers' where Users (say 5 Users) are member of it.
Now, I have an Organization Unit of 'ApplicationsDevelopment&Services' where I need to give access to 'Developers'. Can I associate Groups with OUs, so that members of that Group get necessary access.
I have some policies (SCP) applied on that OU, to manage the access boundaries of Developers.
Please suggest if there is a way to do it or something else needs to be done like ActiveDirectory setup (whole new setup)?
Thank You,
Varun Gupta
I recommend to have a look into AWS SSO (https://aws.amazon.com/single-sign-on/?nc1=h_ls). It comes with no additional cost, is enabled with one click and lets you easily assign cross-account role access to Groups/Users.
Going with an IAM Group which you like to have access to all accounts inside one OU, create roles inside those accounts with a trust relationship to the user/group account. You can use a CloudFormation StackSet to enroll the Stack on OU level. Allow sts:AssumeRole for the particular group, resource section pointing to the role you deployed through the StackSet (leave the account_id blank).
Then everyone inside the group should be able to assume the role and deployment of the cross-account role is centralized.
AWS Org SCPs have account or OU scope, they are not for individual IAM users or roles. From aws blog:
Central security administrators use service control policies (SCPs) with AWS Organizations to establish controls that all IAM principals (users and roles) adhere to.
At the account level, a similar type of maximum permissions gourds on individual users or roles (not groups) can be set using permission boundries. Thus, if you have any roles mapped to your uses through AD, you can look at attaching permissions boundaries to them. But, note that permissions boundaries are an advanced IAM topic, thus its not clear for me how exactly they would apply to your use-case.
I understand the difference between roles and policies but the question
is why these two exists?
I mean why not use AWS Services with Policies?
thanks
IAM roles are similar to IAM users. We create roles to execute operations on required AWS Service.
For example: We can create a role that can perform a write operation
on DynamoDB table and assign that role to a lambda function. Then the
lambda function can use this role's privilege to write something on
DynamoDB.
Policies are simply JSON documents in which we can specify permissions: operations can be allowed or denied. Policies are attached to IAM identities such as users, groups and roles.
So the question is why both exists, why not use AWS service with Policies. The simple answer is we actually are using the AWS services with policies but in the name of IAM user or roles.
Policies get assigned to Roles. Roles do nothing on their own. You should use roles for services for simplicity and security. When assigning roles to a service you don't need to provide AWS access keys directly to these services anymore since they will be provided to the environment by the role. This is much more secure and simple then needing to pass these items to a service or application running on AWS and needing to secure them both on the service and in code.
The AWS official site reads role as a collection of permissions and group as a collection of users. But still they look the same to me. You attach policies to groups or roles, and then assign groups or roles to a user. What exactly are the differences between role and group?
Short answer for googlers: you can't assign role to user.
group is a bunch of users with the same policies
role is a preset of policies for service(s)
Users can asume roles according to AWS docs:
Assuming a Role
AWS Groups are the standard groups which you can consider as collection of several users and a user can belong to multiple groups.
AWS IAM Roles are all together different species; they operate like individual users except that they work mostly towards the impersonation style and perform communication with AWS API calls without specifying the credentials.
Given that IAM Roles are little different, I am emphasizing only that. There are several types of IAM Roles like EC2 IAM Roles, Lambda etc. If you consider, you can launch an EC2 instance with an EC2 IAM Role; hence forth any AWS API related communication wouldn't require any AWS Access Key or Secret key for authentication rather can call the APIs directly (however the long answer is - it uses STS and continuously recycles the credentials behind the scenes); the privileges or permissions of what it can do is determined by the IAM Policies attached to the IAM Role.
Lambda IAM Role works exactly the same, except that only Lambda function can use the Lambda IAM Role etc.
Users: End User (Think People).
Groups: A collection of users under one set of permissions (permission as policy). As per IAM standards we create groups with permissions and then assign user to that group.
Role: you create roles and assign them to AWS resource (AWS resource example can be a customer, supplier, contractor, employee, an EC2 instance, some external application outside AWS) but remember you can't assign role to user.
It’s not only users who will login, sometimes applications need access to AWS resources. For example, an EC2 instance might need to access one or more S3 buckets. Then, an IAM role needs to be created and attached to the EC2 instance. That role can be re-used by different EC2 instances.
Remember : Groups are for living. Roles are for non-living.
I think of an AWS Role as a kind of 'sudo', where each AWS Role can temporarily provide a very specific set of elevated privileges, but without needing the elevated credentials. I get the impression that like sudo, AWS Roles try to prevent privileged actions being used accidentally.
I'd be interested to hear if others agree with this analogy.
Please note that Groups are specific to local IAM users, which are not federated, and local IAM user logs do not show who has done the actions (i.e.., multiple people or applications could use the same long-term secret/access keys, and there is no record of which entity used them). If you must use local IAM users, you can place them into IAM Groups. Where this can be especially useful is to serve as a boundary -- you could place a deny policy on the group, restricting access to specific services or actions, and that deny policy will be applied to all users in the Group.
Conversely, roles can be federated, whereas local IAM users are not. You might create an on-premises AD group that serves as a member container, for example, and then the members of that AD group (and only they) can use the role that the AD group correlates to, with whatever allow or deny policies and/or permissions boundaries you've applied to the role. (Here is a link explaining the AWS ADFS federation.)
Importantly, roles allow for temporary session credentials (which is a best security practice), as their session tokens expire after a maximum of 12 hours. Equally importantly, roles do show in the logs which of the AD members with access to use the role actually did the action. You'll find this tacked to the end of the role ARN in the logs (e.g., a user ID). CloudTrail would be one of several services that indicate user activity. This is important from a logging standpoint.
Understanding IAM roles vs IAM groups (IAM indentities) is very important foundational concept . Its important to look at difference between IAM role and IAM user as essentially group is just a bunch of users performing similar functions (eg. group of developers, QA's etc.) Roles are not uniquely associated with one person (user), they can be assumed by user,resource or service who needs it to perform task at that point of time (session). Roles do not provide long-term credentials like password or access keys.
Best practice recommendation is to require workloads to use temporary credentials with IAM roles to access AWS
Please refer to link below for more clarity:
https://docs.aws.amazon.com/IAM/latest/UserGuide/id.html
I was confused all the time about the difference between these two functions.
In short,
Role is like a tag with all the preset policies that can attach on IAM users/groups or AWS services. IAM users share the same account with the account root user (Admin) but with assigned permissions by the root user to use AWS resources within that account.
Therefore, IAM users can directly interact with AWS services; whereas IAM roles cannot make direct requests to AWS services, they are meant to be assumed by authorised entities like an IAM user or an instance. https://aws.amazon.com/iam/faqs/
I had a hard time deciphering the spirit of the given answers..
Here's what I've found:
Groups:
Intended to represent human users created within IAM who need identical policies.
Ex. Dev 1 - Dev 8 are all developers, and all need access to create dev servers.
This is similar to traditional desktop users/groups, but for HUMAN users only.
Roles:
Roles rotate automatic credentials, meaning password input isn't needed for accessing policies.
This makes it good for two things:
Giving permissions to non-humans, such as services / applications.
Ex. EC2 of type A needs access to S3 of type B.
Giving permissions to federated / outside users & groups.
Ex. Contractor A # Outside Company A needs access to your Server A.
Authentication of users & groups are handled by some service, like Azure AD.
Authorizations are then mapped to your IAM role(s), NOT users or groups.
Note: I've used Jumpcloud's Article & AWS's Documentation to gather this information. The terms "Group", "Role", and "User" become overloaded in context to SSO+IdP, and IAM.
Here's an image showing how they map roles. !Need 10 Reputation :(
Aside: There is a way of assigning Roles to normal IAM Users & Groups, but it appears to be bad practice.
Hopefully this provides clarity to the answers above.
Only one IAM Role can be assumed at a time! And there are several
situations which fits exactly this kind of permission.
Read the faq about: How many IAM roles can I assume?
The underlaying tool in use is "Permission" in both of the use cases namely: Group and IAM Role.
Group or IAM Role --> Has Policy --> Policy defines permisions --> Permissions are assigned to a Group or IAM Role.