Creating and using an IAM policy for IAM database access (original) (raw)

To allow a user or role to connect to your DB instance, you must create an IAM policy. After that, you attach the policy to a permissions set or role.

Note

The following example policy allows a user to connect to a DB instance using IAM database authentication.

{
   "Version": "2012-10-17",
   "Statement": [
      {
         "Effect": "Allow",
         "Action": [
             "rds-db:connect"
         ],
         "Resource": [
             "arn:aws:rds-db:us-east-2:1234567890:dbuser:db-ABCDEFGHIJKL01234/db_user"
         ]
      }
   ]
}

Important

A user with administrator permissions can access DB instances without explicit permissions in an IAM policy. If you want to restrict administrator access to DBinstances, you can create an IAM role with the appropriate, lesser privileged permissions and assign it to the administrator.

Note

Don't confuse the rds-db: prefix with other RDS API operation prefixes that begin withrds:. You use the rds-db: prefix and therds-db:connect action only for IAM database authentication. They aren't valid in any other context.

The example policy includes a single statement with the following elements:

Effect – Specify Allow to grant access to the DB instance. If you don't explicitly allow access, then access is denied by default.
Action – Specify rds-db:connect to allow connections to the DB instance.
Resource – Specify an Amazon Resource Name (ARN) that describes one database account in one DB instance. The ARN format is as follows.

arn:aws:rds-db:region:account-id:dbuser:DbiResourceId/db-user-name

In this format, replace the following:

`region` is the AWS Region for the DB instance. In the example policy, the AWS Region is us-east-2.
`account-id` is the AWS account number for the DBinstance. In the example policy, the account number is1234567890. The user must be in the same account as the account for the DB instance.
To perform cross-account access, create an IAM role with the policy shown above in the account for the DB instance and allow your other account to assume the role.
`DbiResourceId` is the identifier for the DB instance. This identifier is unique to an AWS Region and never changes. In the example policy, the identifier isdb-ABCDEFGHIJKL01234.
To find a DB instance resource ID in the AWS Management Console for Amazon RDS, choose the DB instance to see its details. Then choose the Configuration tab. The Resource ID is shown in the Configuration section.
Alternatively, you can use the AWS CLI command to list the identifiers and resource IDs for all of your DB instance in the current AWS Region, as shown following.

aws rds describe-db-instances --query "DBInstances[*].[DBInstanceIdentifier,DbiResourceId]"

If you are using Amazon Aurora, specify a DbClusterResourceId instead of a DbiResourceId. For more information, see Creating and using an IAM policy for IAM database access in the Amazon Aurora User Guide.

Note

If you are connecting to a database through RDS Proxy, specify the proxy resource ID, such as prx-ABCDEFGHIJKL01234. For information about using IAM database authentication with RDS Proxy, see Connecting to a proxy using IAM authentication.

`db-user-name` is the name of the database account to associate with IAM authentication. In the example policy, the database account is db_user.

You can construct other ARNs to support various access patterns. The following policy allows access to two different database accounts in a DB instance.

{
   "Version": "2012-10-17",
   "Statement": [
      {
         "Effect": "Allow",
         "Action": [
             "rds-db:connect"
         ],
         "Resource": [
             "arn:aws:rds-db:us-east-2:123456789012:dbuser:db-ABCDEFGHIJKL01234/jane_doe",
             "arn:aws:rds-db:us-east-2:123456789012:dbuser:db-ABCDEFGHIJKL01234/mary_roe"
         ]
      }
   ]
}

The following policy uses the "*" character to match all DB instances and database accounts for a particular AWS account and AWS Region.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "rds-db:connect"
            ],
            "Resource": [
                "arn:aws:rds-db:us-east-2:1234567890:dbuser:*/*"
            ]
        }
    ]
}

The following policy matches all of the DB instances for a particular AWS account and AWS Region. However, the policy only grants access to DB instances that have a jane_doe database account.

{
   "Version": "2012-10-17",
   "Statement": [
      {
         "Effect": "Allow",
         "Action": [
             "rds-db:connect"
         ],
         "Resource": [
             "arn:aws:rds-db:us-east-2:123456789012:dbuser:*/jane_doe"
         ]
      }
   ]
}

The user or role has access to only those databases that the database user does. For example, suppose that your DB instance has a database named_dev_, and another database named test. If the database user jane_doe has access only to dev, any users or roles that access that DB instance with the jane_doe user also have access only to dev. This access restriction is also true for other database objects, such as tables, views, and so on.

An administrator must create IAM policies that grant entities permission to perform specific API operations on the specified resources they need. The administrator must then attach those policies to the permission sets or roles that require those permissions. For examples of policies, see Identity-based policy examples for Amazon RDS.

Attaching an IAM policy to a permission set or role

After you create an IAM policy to allow database authentication, you need to attach the policy to a permission set or role. For a tutorial on this topic, see Create and attach your first customer managed policy in the_IAM User Guide_.

As you work through the tutorial, you can use one of the policy examples shown in this section as a starting point and tailor it to your needs. At the end of the tutorial, you have a permission set with an attached policy that can make use of therds-db:connect action.

Note

You can map multiple permission sets or roles to the same database user account. For example, suppose that your IAM policy specified the following resource ARN.


arn:aws:rds-db:us-east-2:123456789012:dbuser:db-12ABC34DEFG5HIJ6KLMNOP78QR/jane_doe

If you attach the policy to Jane,Bob, and Diego, then each of those users can connect to the specified DB instance using the jane_doe database account.