Identity-based policy examples for Amazon GameLift

By default, users and roles don't have permission to create or modify Amazon GameLift resources. They also can't perform tasks by using the AWS Management Console, AWS Command Line Interface (AWS CLI), or AWS API. To grant users permission to perform actions on the resources that they need, an IAM administrator can create IAM policies. The administrator can then add the IAM policies to roles, and users can assume the roles.

To learn how to create an IAM identity-based policy by using these example JSON policy documents, see Creating IAM policies in the IAM User Guide.

For details about actions and resource types defined by Amazon GameLift, including the format of the ARNs for each of the resource types, see Actions, resources, and condition keys for Amazon GameLift in the Service Authorization Reference.

Policy best practices

Identity-based policies determine whether someone can create, access, or delete Amazon GameLift resources in your account. These actions can incur costs for your AWS account. When you create or edit identity-based policies, follow these guidelines and recommendations:

• Get started with AWS managed policies and move toward least-privilege permissions – To get started granting permissions to your users and workloads, use the AWS managed policies that grant permissions for many common use cases. They are available in your AWS account. We recommend that you reduce permissions further by defining AWS customer managed policies that are specific to your use cases. For more information, see AWS managed policies or AWS managed policies for job functions in the IAM User Guide.

• Apply least-privilege permissions – When you set permissions with IAM policies, grant only the permissions required to perform a task. You do this by defining the actions that can be taken on specific resources under specific conditions, also known as least-privilege permissions. For more information about using IAM to apply permissions, see Policies and permissions in IAM in the IAM User Guide.

• Use conditions in IAM policies to further restrict access – You can add a condition to your policies to limit access to actions and resources. For example, you can write a policy condition to specify that all requests must be sent using SSL. You can also use conditions to grant access to service actions if they are used through a specific AWS service, such as AWS CloudFormation. For more information, see IAM JSON policy elements: Condition in the IAM User Guide.

• Use IAM Access Analyzer to validate your IAM policies to ensure secure and functional permissions – IAM Access Analyzer validates new and existing policies so that the policies adhere to the IAM policy language (JSON) and IAM best practices. IAM Access Analyzer provides more than 100 policy checks and actionable recommendations to help you author secure and functional policies. For more information, see IAM Access Analyzer policy validation in the IAM User Guide.

• Require multi-factor authentication (MFA) – If you have a scenario that requires IAM users or a root user in your AWS account, turn on MFA for additional security. To require MFA when API operations are called, add MFA conditions to your policies. For more information, see Configuring MFA-protected API access in the IAM User Guide.

For more information about best practices in IAM, see Security best practices in IAM in the IAM User Guide.

Using the Amazon GameLift console

To access the Amazon GameLift console, you must have a minimum set of permissions. These permissions must allow you to list and view details about the Amazon GameLift resources in your AWS account. If you create an identity-based policy that is more restrictive than the minimum required permissions, the console won't function as intended for entities (users or roles) with that policy.

To ensure that those entities can still use the Amazon GameLift console, add permissions to users and groups with the syntax in the following examples and in Administrator permission examples. For more information, see Manage user permissions for Amazon GameLift.

Users that work with Amazon GameLift through AWS CLI or AWS API operations don't require minimum console permissions. Instead, you can limit access to only the operations the user needs to perform. For example, a player user, acting on behalf of game clients, requires access to request game sessions, place players into games, and other tasks.

For information about the permissions required to use all Amazon GameLift console features, see permissions syntax for administrators in Administrator permission examples.

Allow users to view their own permissions

This example shows how you might create a policy that allows IAM users to view the inline and managed policies that are attached to their user identity. This policy includes permissions to complete this action on the console or programmatically using the AWS CLI or AWS API.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "ViewOwnUserInfo",
            "Effect": "Allow",
            "Action": [
                "iam:GetUserPolicy",
                "iam:ListGroupsForUser",
                "iam:ListAttachedUserPolicies",
                "iam:ListUserPolicies",
                "iam:GetUser"
            ],
            "Resource": ["arn:aws:iam::*:user/${aws:username}"]
        },
        {
            "Sid": "NavigateInConsole",
            "Effect": "Allow",
            "Action": [
                "iam:GetGroupPolicy",
                "iam:GetPolicyVersion",
                "iam:GetPolicy",
                "iam:ListAttachedGroupPolicies",
                "iam:ListGroupPolicies",
                "iam:ListPolicyVersions",
                "iam:ListPolicies",
                "iam:ListUsers"
            ],
            "Resource": "*"
        }
    ]
}

Allow player access for game sessions

To place players into game sessions, game clients and backend services need permissions. For policy examples for these scenarios, see Player user permission examples.

Allow access to one Amazon GameLift queue

The following example provides a user with access to a specific Amazon GameLift queues.

This policy grants the user permissions to add, update, and delete queue destinations with the following actions: gamelift:UpdateGameSessionQueue, gamelift:DeleteGameSessionQueue, and gamelift:DescribeGameSessionQueues. As shown, this policy uses the Resource element to limit access to a single queue: gamesessionqueue/examplequeue123.

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Sid":"ViewSpecificQueueInfo",
         "Effect":"Allow",
         "Action":[
            "gamelift:DescribeGameSessionQueues"
         ],
         "Resource":"arn:aws:gamelift:::gamesessionqueue/examplequeue123"
      },
      {
         "Sid":"ManageSpecificQueue",
         "Effect":"Allow",
         "Action":[
            "gamelift:UpdateGameSessionQueue",
            "gamelift:DeleteGameSessionQueue"
         ],
         "Resource":"arn:aws:gamelift:::gamesessionqueue/examplequeue123"
      }
   ]
}

View Amazon GameLift fleets based on tags

You can use conditions in your identity-based policy to control access to Amazon GameLift resources based on tags. This example shows how you can create a policy that allows viewing a fleet if the Owner tag matches the user's user name. This policy also grants the permissions necessary to complete this operation in the console.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "ListFleetsInConsole",
            "Effect": "Allow",
            "Action": "gamelift:ListFleets",
            "Resource": "*"
        },
        {
            "Sid": "ViewFleetIfOwner",
            "Effect": "Allow",
            "Action": "gamelift:DescribeFleetAttributes",
            "Resource": "arn:aws:gamelift:*:*:fleet/*",
            "Condition": {
                "StringEquals": {"gamelift:ResourceTag/Owner": "${aws:username}"}
            }
        }
    ]
}

Access a game build file in Amazon S3

After you integrate your game server with Amazon GameLift, upload the build files to Amazon S3. For Amazon GameLift to access the build files, use the following policy.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:GetObject",
                "s3:GetObjectVersion"
            ],
            "Resource": "arn:aws:s3:::bucket-name/object-name"
        }
    ]
}

For more information about uploading Amazon GameLift game files, see Upload a custom server build to Amazon GameLift.