Securing Infrastructure Access at Scale in Large Enterprises
Dec 12
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Database Access with Amazon ElastiCache and Amazon MemoryDB for Redis

Teleport can provide secure access to Amazon ElastiCache or MemoryDB for Redis 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 ElastiCache or MemoryDB for Redis 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 proxies traffic from users to Amazon ElastiCache or MemoryDB for Redis. Authentication between the Database Service and the AWS-hosted Redis database can take one of two forms:

  • IAM authentication (preferred): The Teleport Database Service connects to the database using a short-lived AWS IAM authentication token. AWS IAM authentication is available for ElastiCache and MemoryDB with Redis version 7.0 or above.
  • Managing users: The Teleport Database Service manages users in a Redis access control list, rotates their passwords every 15 minutes, and saves these passwords in AWS Secrets Manager. The Database Service automatically sends an AUTH command with the saved password when connecting the client to the Redis server.

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

Prerequisites

  • A running Teleport cluster version 16.4.10 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 at least one ElastiCache or MemoryDB for Redis cluster. In-transit encryption via (TLS) must be enabled.
  • Permissions to create and attach IAM policies.
  • redis-cli version 6.2 or newer 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.
  • Redis ACL enabled for your ElastiCache or MemoryDB for Redis cluster.
  • A running Teleport Discovery Service if you plan to use Database Auto-Discovery.
  • 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 16.4.10

    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

Tip

To modify an existing user to provide access to the Database Service, see Database Access Controls

Create a local Teleport user with the built-in access role:

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

Create a local Teleport user with the built-in access and requester roles:

tctl users add \ --roles=access,requester \ --db-users="*" \ --db-names="*" \ alice
FlagDescription
--rolesList of roles to assign to the user. The builtin access role allows them to connect to any database server registered with Teleport.
--db-usersList of database usernames the user will be allowed to use when connecting to the databases. A wildcard allows any user.
--db-namesList of logical databases (aka schemas) the user will be allowed to connect to within a database server. A wildcard allows any database.
Warning

Database names are only enforced for PostgreSQL, MongoDB, and Cloud Spanner databases.

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

For users with a lot of infrastructure in AWS, or who might create or recreate many instances, consider alternative methods for joining new EC2 instances running Teleport:

Install Teleport on your Linux server:

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

    EditionValue
    Teleport Enterprise Cloudcloud
    Teleport Enterprise (Self-Hosted)enterprise
    Teleport Community Editionoss
  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-v16.4.10.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.

Create the Database Service configuration:

Change example.teleport.sh:443 to the host and port of your Teleport Proxy Service. Set ELASTICACHE_URI to the domain name and port of your ElastiCache database:

ELASTICACHE_URI=""
sudo teleport db configure create \ -o file \ --name="elasticache" \ --proxy=example.teleport.sh:443 \ --protocol="redis" \ --uri=${ELASTICACHE_URI?} \ --token=/tmp/token

Change example.teleport.sh:443 to the host and port of your Teleport Proxy Service. Set MEMORYDB_URI to the domain name and port of your ElastiCache database:

MEMORYDB_URI=""
sudo teleport db configure create \ -o file \ --name="memorydb" \ --proxy=example.teleport.sh:443 \ --protocol="redis" \ \ --uri=${MEMORYDB_URI} \ --token=/tmp/token

The command will generate a Database Service configuration and place it at the /etc/teleport.yaml location.

Step 3/6. Create an IAM role for Teleport

The Teleport Database Service needs AWS IAM permissions to provide access to ElastiCache or MemoryDB databases.

Create an IAM role for Teleport

Grant the Database Service access to credentials that it can use to authenticate to AWS.

  • If you are running the Database Service on an EC2 instance, you may use the EC2 Instance Metadata Service method
  • If you are running the Database Service in Kubernetes, you can use IAM Roles for Service Accounts (IRSA)
  • Otherwise, you must use environment variables

Teleport will detect when it is running on an EC2 instance and use the Instance Metadata Service to fetch credentials.

The EC2 instance should be configured to use an EC2 instance profile. For more information, see: Using Instance Profiles.

Refer to IAM Roles for Service Accounts (IRSA) to set up an OIDC provider in AWS and configure an AWS IAM role that allows the pod's service account to assume the role.

Teleport's built-in AWS client reads credentials from the following environment variables:

  • AWS_ACCESS_KEY_ID
  • AWS_SECRET_ACCESS_KEY
  • AWS_DEFAULT_REGION

When you start the Database Service, the service reads environment variables from a file at the path /etc/default/teleport. Obtain these credentials from your organization. Ensure that /etc/default/teleport has the following content, replacing the values of each variable:

AWS_ACCESS_KEY_ID=00000000000000000000
AWS_SECRET_ACCESS_KEY=0000000000000000000000000000000000000000
AWS_DEFAULT_REGION=<YOUR_REGION>

Teleport's AWS client loads credentials from different sources in the following order:

  • Environment Variables
  • Shared credentials file
  • Shared configuration file (Teleport always enables shared configuration)
  • EC2 Instance Metadata (credentials only)

While you can provide AWS credentials via a shared credentials file or shared configuration file, you will need to run the Database Service with the AWS_PROFILE environment variable assigned to the name of your profile of choice.

If you have a specific use case that the instructions above do not account for, consult the documentation for the AWS SDK for Go for a detailed description of credential loading behavior.

Grant permissions

Attach the following AWS IAM permissions to the Database Service IAM role:

ElastiCache supports IAM authentication for Redis engine version 7.0 or above. This is the recommended way to configure Teleport access to ElastiCache.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "ElastiCacheDescribeUsers",
            "Effect": "Allow",
            "Action": "elasticache:DescribeUsers",
            "Resource": "*"
        },
        {
            "Sid": "ElastiCacheConnect",
            "Effect": "Allow",
            "Action": "elasticache:Connect",
            "Resource": [
                "arn:aws:elasticache:us-east-2:aws-account-id:replicationgroup:replication-group",
                "arn:aws:elasticache:us-east-2:aws-account-id:user:*"
            ]
        }
    ]
}
StatementPurpose
ElastiCacheDescribeUsersDetermine whether a user is compatible with IAM authentication.
ElastiCacheConnectConnect using IAM authentication.

See Authenticating with IAM for ElastiCache for more information.

MemoryDB supports IAM authentication for Redis engine version 7.0 or above. This is the recommended way to configure Teleport access to MemoryDB.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "MemoryDBDescribeUsers",
            "Effect": "Allow",
            "Action": "memorydb:DescribeUsers",
            "Resource": "*"
        },
        {
            "Sid": "MemoryDBConnect",
            "Effect": "Allow",
            "Action": "memorydb:Connect",
            "Resource": [
                "arn:aws:memorydb:us-east-2:aws-account-id:replicationgroup:replication-group",
                "arn:aws:memorydb:us-east-2:aws-account-id:user:*"
            ]
        }
    ]
}
StatementPurpose
MemoryDBDescribeUsersDetermine whether a user is compatible with IAM authentication.
MemoryDBConnectConnect using IAM authentication.

See Authenticating with IAM for MemoryDB for more information.

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.

On the host where you will run the Database Service, enable and start Teleport:

sudo systemctl enable teleport
sudo systemctl start teleport

On the host where you will run the Database Service, create a systemd service configuration for Teleport, enable the Teleport service, and 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.

Step 5/6. Configure authentication for ElastiCache or MemoryDB users

Configure authentication for your AWS-hosted Redis database. The steps to follow depend on whether you want to enable the Teleport Database Service to use IAM authentication with ElastiCache, IAM authentication with MemoryDB, or authentication based on managing passwords via AWS Secrets Manager:

To enable Redis ACL, please see Authenticating users with Role-Based Access Control for ElastiCache.

Some additional limitations apply when using IAM authentication - for more information, see: ElastiCache Auth IAM Limits.

There are a few requirements for configuring an ElastiCache IAM-enabled user:

  • the user must have identical username and user id properties.
  • the user must have authentication mode set to "IAM".
  • the user must be attached to an ElastiCache user group.

Create an ElastiCache IAM-enabled user. The following example creates an ElastiCache user with the access string on ~* +@all that represents an active user with access to all available keys and commands:

aws elasticache create-user \ --user-name iam-user-01 \ --user-id iam-user-01 \ --authentication-mode Type=iam \ --engine redis \ --access-string "on ~* +@all"
Access Strings

You may prefer a less permissive access string for your ElastiCache users. For more information about ElastiCache access strings, please see: ElastiCache Cluster RBAC Access String.

Create an ElastiCache user group and attach it to your ElastiCache replication group:

aws elasticache create-user-group \ --user-group-id iam-user-group-01 \ --engine redis \ --user-ids default iam-user-01
aws elasticache modify-replication-group \ --replication-group-id replication-group-01 \ --user-group-ids-to-add iam-user-group-01

Once the ElastiCache user has been created, verify that the user is configured to satisfy the requirements for IAM authentication:

It is highly recommended to use a different ACL than the preset open-access ACL which allows all access using the default user.

If you do not have another MemoryDB ACL yet, create one:

aws memorydb create-acl --acl-name my-acl

Make sure the ACL is attached to your MemoryDB cluster:

aws memorydb update-cluster --cluster-name my-memorydb --acl-name my-acl

Now create an MemoryDB IAM-enabled user:

aws memorydb create-user \ --user-name iam-user-01 \ --authentication-mode Type=iam \ --access-string "on ~* +@all"
Access Strings

The above example creates a MemoryDB user with the access string on ~* +@all that represents an active user with access to all available keys and commands.

You may prefer a less permissive access string for your MemoryDB users. For more information about access strings, please see: Specifying Permissions Using an Access String.

Then add this user to the ACL attached to your MemoryDB cluster:

aws memorydb update-acl --user-names-to-add iam-user-01 --acl-name my-acl

To enable Redis ACL, please see Authenticating users with Role-Based Access Control for ElastiCache and Authenticating users with Access Control Lists for MemoryDB.

Once an ElastiCache or MemoryDB user is created with the desired access, add an AWS resource tag teleport.dev/managed with the value true to this user:

The Database Service will automatically discover this user if it is associated with a registered database. Keep in mind that it may take the Database Service some time (up to 20 minutes) to discover this user once the tag is added.

If you choose not to use the above options, Teleport will not automatically authenticate with the Redis server.

You can either set up a "no password" configuration for your ElastiCache or MemoryDB user, or manually enter an AUTH command with the password you have configured after a successful client connection. However, it is strongly advised to use one of the first two options or a strong password for better security.

Step 6/6. Connect

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

tsh login --proxy=teleport.example.com --user=alice
tsh db ls

Name Description Labels

--------------------------- --------------------------------------------------------- --------

my-cluster-mode-elasticache ...

my-elasticache ...

my-elasticache-reader ...

my-memorydb ...

tsh login --proxy=mytenant.teleport.sh --user=alice
tsh db ls

Name Description Labels

--------------------------- --------------------------------------------------------- --------

my-cluster-mode-elasticache ...

my-elasticache ...

my-elasticache-reader ...

my-memorydb ...

To retrieve credentials for a database and connect to it:

tsh db connect --db-user=my-database-user my-elasticache

If flag --db-user is not provided, Teleport logs in as the default user.

Now, depending on the authentication configurations, you may need to send an AUTH command to authenticate with the Redis server:

The Database Service automatically authenticates Teleport-managed and IAM-enabled users with the Redis server. No AUTH command is required after successful connection.

If you are connecting as a user that is not managed by Teleport and is not IAM-enabled, the connection normally starts as the default user. Now you can authenticate the database user with its password:

AUTH my-database-user <USER_PASSWORD>

Now you can authenticate with the shared AUTH token:

AUTH <SHARED_AUTH_TOKEN>

For Redis deployments without the ACL system or legacy requirepass directive enabled, no AUTH command is required.

To log out of the database and remove credentials:

Remove credentials for a particular database instance.

tsh db logout my-elasticache

Remove credentials for all database instances.

tsh db logout

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.

When both of the above conditions are true for a database connection, the Database Service performs a role chaining by assuming the IAM role specified in assume_role_arn first, then using that IAM role to assume the IAM role for the database user.

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

To allow IAM Role teleport-db-service-role to assume IAM Role db-user-role, the following is generally required:

1. Configure Trust Relationships on db-user-role

teleport-db-service-role or its AWS account should be set as Principal in db-user-role's trust policy.

{
  "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"
        }
      }
    }
  ]
}

2. Configure Permissions Policies on teleport-db-service-role

teleport-db-service-role requires sts:AssumeRole permissions, for example:

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

Note that this policy can be omitted when teleport-db-service-role and db-user-role are in the same AWS account and teleport-db-service-role's full ARN is configured as Principal in db-user-role's trust policy.

3. Configure Permissions Boundary on teleport-db-service-role

If teleport-db-service-role does not have an attached Permissions boundary then you can skip this step. Otherwise, the boundary policy attached to teleport-db-service-role must include sts:AssumeRole permissions, for example:

{
    "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.

Next steps

  • Take a look at the YAML configuration reference.