Database Access with Amazon DocumentDB

Teleport can provide secure access to Amazon DocumentDB via the Teleport Database Service. This allows for fine-grained access control through Teleport's RBAC.

In this guide, you will:

1. Configure your Amazon DocumentDB database with IAM authentication.
2. Add the database to your Teleport cluster.
3. Connect to the database via Teleport.

How it works

The Teleport Database Service uses IAM authentication to communicate with Amazon DocumentDB. When a user connects to the database via Teleport, the Teleport Database Service obtains AWS credentials and authenticates to AWS as an IAM principal with permissions to access the database.

• Self-Hosted
• Cloud-Hosted

This guide shows how to register a single Amazon DocumentDB cluster with your Teleport cluster. For a more scalable approach, learn how to set up Database Auto-Discovery to automatically enroll all databases in your infrastructure.

Prerequisites

• A running Teleport cluster version 16.3.0 or above. If you want to get started with Teleport, sign up for a free trial or set up a demo environment.

• The tctl admin tool and tsh client tool.

  Visit Installation for instructions on downloading tctl and tsh.

• AWS account with a DocumentDB cluster.

  IAM authentication and TLS

  Teleport uses IAM authentication to connect users to DocumentDB, which is only supported for DocumentDB 5.0 or higher.

  In addition, the DocumentDB cluster must have Transport Layer Security (TLS) enabled. TLS is enabled by default when using the default parameter group.

• Command-line client mongosh or mongo installed and added to your system's PATH environment variable.

• A host, e.g., an EC2 instance, where you will run the Teleport Database Service.

• To check that you can connect to your Teleport cluster, sign in with tsh login, then verify that you can run tctl commands using your current credentials.

  For example:

  tsh login --proxy=teleport.example.com --user=[email protected]
  tctl status
  Cluster  teleport.example.com
  Version  16.3.0
  CA pin   sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678

  If you can connect to the cluster and run the tctl status command, you can use your current credentials to run subsequent tctl commands from your workstation. If you host your own Teleport cluster, you can also run tctl commands on the computer that hosts the Teleport Auth Service for full permissions.

Step 1/6. Create a Teleport user

tctl users add \  --roles=access \  --db-users="*" \  --db-names="*" \  alice

tctl users add \  --roles=access,requester \  --db-users="*" \  --db-names="*" \  alice

For more detailed information about database access controls and how to restrict access see RBAC documentation.

Step 2/6. Create a Database Service configuration

The Database Service requires a valid join token to join your Teleport cluster. Run the following tctl command and save the token output in /tmp/token on the server that will run the Database Service:

tctl tokens add --type=db --format=text
abcd123-insecure-do-not-use-this

Install Teleport on your Linux server:

1. Assign edition to one of the following, depending on your Teleport edition:

   Edition	Value
   Teleport Enterprise Cloud	cloud
   Teleport Enterprise (Self-Hosted)	enterprise
   Teleport Community Edition	oss

2. Get the version of Teleport to install. If you have automatic agent updates enabled in your cluster, query the latest Teleport version that is compatible with the updater:

   TELEPORT_DOMAIN=example.teleport.com
   TELEPORT_VERSION="$(curl https://$TELEPORT_DOMAIN/v1/webapi/automaticupgrades/channel/default/version | sed 's/v//')"

   Otherwise, get the version of your Teleport cluster:

   TELEPORT_DOMAIN=example.teleport.com
   TELEPORT_VERSION="$(curl https://$TELEPORT_DOMAIN/v1/webapi/ping | jq -r '.server_version')"

3. Install Teleport on your Linux server:

   curl https://cdn.teleport.dev/install-v16.3.0.sh | bash -s ${TELEPORT_VERSION} edition

   The installation script detects the package manager on your Linux server and uses it to install Teleport binaries. To customize your installation, learn about the Teleport package repositories in the installation guide.

On the node that is running the Database Service, create a configuration file. Use your DocumentDB cluster endpoint and port as the URI:

sudo teleport db configure create \   -o file \   --name="my-docdb" \   --proxy=example.teleport.sh:443 \   --protocol=mongodb \   --token=/tmp/token \   --uri="my-docdb.cluster-abcdefghijklm.us-east-1.docdb.amazonaws.com:27017"

The command will generate a Database Service configuration to proxy your AWS DocumentDB cluster and save the configuration to /etc/teleport.yaml.

Step 3/6. Create an IAM role for the Database Service

First, visit the IAM > Policies page of the AWS Console, then press "Create policy".

Use the JSON option for Policy editor and paste in the following policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "rds:DescribeDBClusters"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "sts:AssumeRole"
            ],
            "Resource": "*",
            "Condition": {
                "StringEquals": {"iam:ResourceTag/TeleportDatabaseService": "Allowed"}
            }
        }
    ]
}

This policy allows Teleport Database Service to retrieve DocumentDB cluster metadata and assume IAM roles to authenticate as DocumentDB users. Note that the sts:AssumeRole has a resource tag condition to limit the IAM roles the Teleport Database Service can assume.

Click Next and give the policy a name. In this guide, we will use the example name TeleportDatabaseAccessDocumentDB.

Now visit the IAM > Roles page of the AWS Console, then press "Create Role". Under Trusted entity type select "AWS service". Under Use case select "EC2" or the intended use case, then click Next.

On the "Add Permissions" page, find and select the TeleportDatabaseAccessDocumentDB policy that is created in the previous step.

Click "Next" and give the role a name. In this guide, we will use the example name TeleportDatabaseService for this role. Once you have chosen a name, click Create Role to complete the process.

Step 4/6. Start the Database Service

Configure the Database Service to start automatically when the host boots up by creating a systemd service for it. The instructions depend on how you installed the Database Service.

sudo systemctl enable teleport
sudo systemctl start teleport

sudo teleport install systemd -o /etc/systemd/system/teleport.service
sudo systemctl enable teleport
sudo systemctl start teleport

You can check the status of the Database Service with systemctl status teleport and view its logs with journalctl -fu teleport.

The Database Service will proxy the Amazon DocumentDB cluster with the URI you specified earlier. Keep in mind that AWS IAM changes may not propagate immediately and can take a few minutes to come into effect.

Step 5/6. Create an IAM role for a DocumentDB user

In this step, we will create an IAM role that the Teleport Database Service can assume to authenticate to DocumentDB on behalf of a Teleport user.

Create an IAM role

Navigate back to the Roles page on the AWS Web Console and create a new role. Select the "AWS account" option, which creates a default trust policy to allow other entities in this account to assume this role:

Skip the "Add Permissions" page by clicking "Next", and give the role a name. In this guide, we will use the example "teleport-docdb-user" for this role.

Now click Add new tag at Step 3, use TeleportDatabaseService for the key and Allowed for the value. Then click Create Role to complete the process.

Create a DocumentDB user

Log in to your DocumentDB cluster with your master username and password from a machine that has network access to the DocumentDB cluster. Create a DocumentDB user with the IAM role ARN as username and specify MONGODB-AWS in the mechanisms for authentication:

use $external;db.createUser(    {        user: "arn:aws:iam::123456789012:role/teleport-docdb-user",        mechanisms: ["MONGODB-AWS"],        roles: [ { role: "root", db: "admin" },  ]    });

This example creates a DocumentDB IAM user with root privileges. You can adjust the privileges as required.

Step 6/6 Connect

Once the Database Service has started and joined the cluster, log in to see the registered databases:

tsh login --proxy=example.teleport.sh:443 --user=alice
tsh db ls
Name     Description Labels
-------- ----------- --------
my-docdb             env=dev

Retrieve credentials for the database and connect to it as the teleport-docdb-user user:

tsh db connect --db-user=teleport-docdb-user --db-name=test my-docdb

Log out of the database and remove credentials:

tsh db logout rds-example

Troubleshooting

Certificate error

If your tsh db connect error includes the following text, you likely have an RDS or DocumentDB database created before July 28, 2020, which presents an X.509 certificate that is incompatible with Teleport:

x509: certificate relies on legacy Common Name field, use SANs instead

AWS provides instructions to rotate your SSL/TLS certificate.

No credential providers error

If you see the error NoCredentialProviders: no valid providers in chain in Database Service logs then Teleport is not detecting the required credentials to connect via AWS IAM permissions. Check whether the credentials or security role has been applied in the machine running the Teleport Database Service.

When running on EKS, this error may occur if the Teleport Database Service cannot access IMDSv2 when the PUT requests hop limit on the worker node instance is set to 1. You can use the following commands to check the hop limit:

aws ec2 describe-instances --instance-ids <node-instance-id> | grep HttpPutResponseHopLimit
                        "HttpPutResponseHopLimit": 1,

See IMDSv2 support for EKS and EKS best practices for more details.

Timeout errors

The Teleport Database Service needs connectivity to your database endpoints. That may require enabling inbound traffic on the database from the Database Service on the same VPC or routing rules from another VPC. Using the nc program you can verify connections to databases:

nc -zv postgres-instance-1.sadas.us-east-1.rds.amazonaws.com 5432
Connection to postgres-instance-1.sadas.us-east-1.rds.amazonaws.com (172.31.24.172) 5432 port [tcp/postgresql] succeeded!

Not authorized to perform sts:AssumeRole

The Database Service assumes an IAM role in one of following situations:

• A Teleport user specifies an IAM role as the database user they wish to use when accessing AWS services that require IAM roles as database users. Databases that support using an IAM role as a database user include: DynamoDB, Keyspaces, Opensearch, Redshift, and Redshift Serverless.
• The assume_role_arn field is specified for the database resources or dynamic resource matchers.

You may encounter the following error if the trust relationship is not configured properly between the IAM roles:

AccessDenied: User: arn:aws:sts::111111111111:assumed-role/teleport-db-service-role/i-* is not authorized to perform: sts:AssumeRole on resource: arn:aws:iam::111111111111:role/db-user-role

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::aws-account-id:role/teleport-db-service-role"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::aws-account-id:root"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::external-aws-account-id:role/teleport-db-service-role"
      },
      "Action": "sts:AssumeRole",
      "Condition": {
        "StringEquals": {
          "sts:ExternalId": "example-external-id"
        }
      }
    }
  ]
}

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": "sts:AssumeRole",
            "Effect": "Allow",
            "Resource": "arn:aws:iam::aws-account-id:role/db-user-role"
        }
    ]
}

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": "sts:AssumeRole",
            "Effect": "Allow",
            "Resource": "*"
        }
    ]
}

You can test the trust relationship by running this AWS CLI command as teleport-db-service-role:

aws sts assume-role --role-arn arn:aws:iam::111111111111:role/db-user-role --role-session-name test-trust-relationship

Learn more on how to use trust policies with IAM roles.

Unable to authenticate using mechanism "MONGODB-AWS" error

You may encounter the following error when IAM authentication fails:

tsh db connect --db-user=teleport-docdb-user --db-name=test my-docdb
...MongoServerSelectionError: error connecting to the database	connection() error occurred during connection handshake: auth error: sasl conversation error: unable to authenticate using mechanism "MONGODB-AWS":  Authentication failed.ERROR: exit status 1

Make sure the IAM role exists as a DocumentDB user in the "$external" database of the target DocumentDB cluster and the DocumentDB user is configured with MONGODB-AWS mechanisms for authentication.

See Authentication using IAM identity for more details.

Next steps

• Learn how to restrict access to certain users and databases.

• View the High Availability (HA) guide.

• Take a look at the YAML configuration reference.

• See the full CLI reference.

• Learn more about Authentication using IAM identity for DocumentDB for more details.