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Version: 19.x (unreleased)

Database Access with Amazon ElastiCache Serverless for Redis and Valkey

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Teleport can provide secure access to Amazon ElastiCache Serverless 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 Serverless 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 connects on user behalf using IAM authentication and proxies traffic from users to Amazon ElastiCache Serverless.

This guide shows how to register a single Amazon Elasticache Serverless cache 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. If you do not have one, read Getting Started.

  • The tctl and tsh clients.

    Installing tctl and tsh clients

    1. Determine the version of your Teleport cluster. The tctl and tsh clients must be at most one major version behind your Teleport cluster version. Send a GET request to the Proxy Service at /v1/webapi/find and use a JSON query tool to obtain your cluster version. Replace teleport.example.com:443 with the web address of your Teleport Proxy Service:

      TELEPORT_DOMAIN=teleport.example.com:443
      TELEPORT_VERSION="$(curl -s https://$TELEPORT_DOMAIN/v1/webapi/find | jq -r '.server_version')"

    2. Follow the instructions for your platform to install tctl and tsh clients:

      Download the signed macOS .pkg installer for Teleport, which includes the tctl and tsh clients:

      curl -O https://cdn.teleport.dev/teleport-${TELEPORT_VERSION?}.pkg

      In Finder double-click the pkg file to begin installation.

      danger

      Using Homebrew to install Teleport is not supported. The Teleport package in Homebrew is not maintained by Teleport and we can't guarantee its reliability or security.

  • AWS account with an ElastiCache Serverless for Redis or Valkey cache.
  • 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.
  • 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, run the following command, assigning teleport.example.com to the domain name of the Teleport Proxy Service in your cluster and [email protected] to your Teleport username: 
    tsh login --proxy=teleport.example.com --user=[email protected]
    tctl status
    Cluster  teleport.example.com
    Version  19.0.0-dev
    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
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
Alternative methods

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:

To install a Teleport Agent on your Linux server:

The easiest installation method, for Teleport versions 17.3 and above, is the cluster install script. It will use the best version, edition, and installation mode for your cluster.

  1. Assign teleport.example.com:443 to your Teleport cluster hostname and port, but not the scheme (https://).

  2. Run your cluster's install script:

    curl "https://teleport.example.com:443/scripts/install.sh" | sudo bash

On older Teleport versions:

  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=teleport.example.com:443
    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=teleport.example.com:443
    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.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:

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

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

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 Serverless caches.

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.

Have multiple sources of AWS credentials?

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​

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "ElastiCacheServerlessFetchMetadata",
            "Effect": "Allow",
            "Action": "elasticache:DescribeServerlessCaches",
            "Resource": "*"
        },
        {
            "Sid": "ElastiCacheServerlessDescribeUsers",
            "Effect": "Allow",
            "Action": "elasticache:DescribeUsers",
            "Resource": "*"
        },
        {
            "Sid": "ElastiCacheServerlessConnect",
            "Effect": "Allow",
            "Action": "elasticache:Connect",
            "Resource": "*"
        }
    ]
}
StatementPurpose
ElastiCacheServerlessFetchMetadataAutomatically import AWS metadata about the database.
ElastiCacheServerlessDescribeUsersDetermine whether a user is compatible with IAM authentication.
ElastiCacheServerlessConnectConnect using IAM authentication.
Details

You can reduce the scope of the ElastiCacheServerlessConnect statement by updating it to only allow specific ElastiCache Serverless caches and IAM users. The resource ARN you can specify has the following formats:

arn:aws:elasticache:{Region}:{AccountID}:serverlesscache:{CacheName}arn:aws:elasticache:{Region}:{AccountID}:user:{UserName}

See Authenticating with IAM for ElastiCache 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

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 users​

Configure authentication for your ElastiCache Serverless database.

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

warning

ElastiCache Serverless Redis OSS will automatically create a default user with no password. We strongly recommend that you take steps to disable the default user. The automatically created default user cannot be modified or deleted and you cannot remove the default user name from an ElastiCache Redis OSS user group. To disable the default user:

  1. create a new user with the user name "default" and a unique (i.e., not "default") user ID.
  2. replace the default user in your ElastiCache user group with the new default user.

We recommend setting a strong password on your customized default user (IAM authentication is not possible for the default user) and using an access string that is not permissive. For example, the access string off -@all will disable logins and deny all Redis privileges to the default user.

See Applying RBAC for more information.

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 Serverless cache:

aws elasticache create-user-group \  --user-group-id iam-user-group-01 \  --engine redis \  --user-ids default iam-user-01
aws elasticache modify-serverless-cache \    --serverless-cache-name serverless-cache-1 \    --user-group-id "iam-user-group-01"

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

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

You can either set up a "no password" configuration for your ElastiCache Serverless 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 Allowed Users Labels------------------- ----------- ------------- -----------------------my-serverless-cache             [*]           account_id=123456789012

To retrieve credentials for a database and connect to it:

tsh db connect --db-user=my-database-user my-serverless-cache

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 database. 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>

To log out of the database and remove credentials:

Remove credentials for a particular database instance.
tsh db logout my-serverless-cache
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 requires connectivity to your database endpoints.

Check that firewall rules (e.g., AWS security groups) allow connectivity between the Teleport Database Service and the database endpoint.

  • Inbound firewall rules for the database must allow connections from the Teleport Database Service.
  • Outbound firewall rules for the Teleport Database Service must allow connections to the database endpoint.
tip

On the same host as the Teleport Database Service, try running nc to check if it can reach the database port.

  • Database host: postgres-instance-1.sadas.us-east-1.rds.amazonaws.com
  • Database port: 5432
nc -zv database-host database-port
Connection to postgres-instance-1.sadas.us-east-1.rds.amazonaws.com (172.31.24.172) 5432 port [tcp/postgresql] succeeded!
Debugging connection timeout errors in AWS

For deployments in AWS, it may be helpful to use AWS Reachability Analyzer to analyze the network path between the Teleport Database Service and the database.

  1. Identify the Elastic Network Interface (ENI) associated with the Teleport Database Service host. This can be found in the EC2 console.
  2. Identify the private IP address of the database.
  3. Create and analyze a network path:
    • Set the path source to the ENI associated with the Teleport Database Service host.
    • Set the path destination to the database IP.
  4. Check the analysis results to identify reachability issues.

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.
What if both situations apply? (role chaining)

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
how to properly configure the trust relationship?

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.

Assign aws-account-id to your AWS account ID:

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

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.