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Database Access with Redshift on AWS

Federating Amazon Redshift Access using Teleport

Federating Amazon Redshift Access using Teleport

Length: 08:11

Teleport can provide secure access to Amazon Redshift 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 Redshift 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 Redshift. 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 manage the database.

This guide shows how to enroll a single Amazon Redshift cluster through the Teleport Database Service. For a more scalable approach, learn how to configure the Teleport Discovery Service to automatically enroll all AWS databases in your infrastructure.

Prerequisites

  • A running Teleport cluster version 16.0.0 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 Redshift cluster and permissions to create and attach IAM policies.
  • Command-line client psql 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. tctl is supported on macOS and Linux machines. For example:
    tsh login --proxy=teleport.example.com --user=[email protected]
    tctl status

    Cluster teleport.example.com

    Version 16.0.0

    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

Tip

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

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://goteleport.com/static/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.

On the node that is running the Database Service, create a configuration file. Assign CLUSTER_URI to the domain name and port of the cluster:

sudo teleport db configure create \ -o file \ --name="redshift-postgres" \ --proxy=teleport.example.com:3080 \ --protocol=postgres \ --token=/tmp/token \ --uri=${CLUSTER_URI?}
sudo teleport db configure create \ -o file \ --name="redshift-postgres" \ --proxy=mytenant.teleport.sh:443 \ --protocol=postgres \ --token=/tmp/token \ --uri=${CLUSTER_URI?}

The command will generate a Database Service configuration to proxy your AWS Redshift cluster place it at the /etc/teleport.yaml location.

Step 3/6. Create an IAM Role for user access (optional)

Redshift supports two methods of IAM authentication, both of which Teleport also supports.

First is IAM authentication as a database user. In this method, the Teleport Database Service generates a temporary IAM authentication token for a database user that already exists in the Redshift database. If you choose to use this method, you can skip this step as no additional IAM roles are required.

The second method is to authenticate as an IAM role. In this case, the Teleport Database Service assumes an IAM role to authenticate with Redshift. Redshift then maps that IAM role to a database username and creates that database user if it doesn't already exist in the database.

If you choose the second method, create the AWS IAM role to provide user access to the Redshift database. Go to IAM -> Access Management -> Roles, and click "Create Role".

Skip "Add permissions" for now, enter a role name, and press "Create role".

Once the role is created, find the role, and add the following inline policy to the IAM role:

Or in JSON format:

{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Effect": "Allow",
			"Action": "redshift:GetClusterCredentialsWithIAM",
			"Resource": "arn:aws:redshift:us-east-1:123456789012:dbname:my-redshift/*"
		}
	]
}

Replace 123456789012 and my-redshift with your AWS account ID and your Redshift database's cluster ID.

Step 4/6. Create an IAM policy for the Database Service

Teleport needs AWS IAM permissions to be able to:

  • Manage IAM user or IAM role policies, for IAM authentication as database users.
  • Assume IAM roles, for IAM authentication as IAM roles.

Before you can generate IAM permissions, you must provide the Teleport Database Service access to AWS credentials.

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. 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.

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.

Teleport can bootstrap IAM permissions for the Database Service based on its configuration using the teleport db configure bootstrap command. You can use this command in automatic or manual mode:

  • In automatic mode, Teleport will attempt to create appropriate IAM policies and attach them to the specified IAM identity (user or role). This requires IAM permissions to create and attach IAM policies.
  • In manual mode, Teleport will print required IAM policies. You can then create and attach them manually using the AWS management console.

Use this command to bootstrap the permissions automatically when your Teleport Database Service runs as an IAM user (for example, uses an AWS credentials file).

teleport db configure bootstrap -c /etc/teleport.yaml --attach-to-user TeleportUser

Use this command to bootstrap the permissions automatically when your Teleport Database Service runs as an IAM role (for example, on an EC2 instance with an attached IAM role).

teleport db configure bootstrap -c /etc/teleport.yaml --attach-to-role TeleportRole

Use this command to display required IAM policies which you will then create in your AWS console:

teleport db configure bootstrap -c /etc/teleport.yaml --manual --attach-to-user arn:aws:iam::123456789012:user/TeleportUser

Use this command to display required IAM policies which you will then create in your AWS console:

teleport db configure bootstrap -c /etc/teleport.yaml --manual --attach-to-role arn:aws:iam::123456789012:role/TeleportRole

When assume_role_arn is configured for databases or AWS matchers, teleport db configure bootstrap will determine permissions required for the bootstrap target AWS IAM identity using the following logic:

  • When the target does not match assume_role_arn in any database resource or AWS matcher in the configuration file, the target is assumed to be the Teleport Database Service's AWS IAM identity and permissions are bootstrapped for all the configured static databases and AWS matchers.
  • When an --attach-to-role target matches an assume_role_arn setting for static databases or AWS matchers in the configuration file, permissions will be bootstrapped only for those static databases or AWS matchers.

You will need to run the bootstrap command once with the Teleport Database Service's IAM identity as the policy attachment target, and once for each AWS IAM role that is used for assume_role_arn.

Step 5/6. 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.

The Database Service will proxy the Amazon Redshift cluster with the ID 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 6/6. Connect

Once the Database Service has started and joined the cluster, log in to see the registered databases. Replace --proxy with the address of your Teleport Proxy Service.

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

Name Description Labels

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

my-redshift ...

Once the Database Service has started and joined the cluster, log in to see the registered databases. Replace --proxy with the address of your Teleport Cloud tenant.

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

Name Description Labels

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

my-redshift ...

To retrieve credentials for a database and connect to it:

tsh db connect --db-user=alice --db-name=dev my-redshift
Database users must exist

Teleport does not currently use the auto-create option when generating tokens for Redshift databases. Users must exist in the database.

tsh db connect --db-user=role/my-iam-role --db-name=dev my-redshift

To log out of the database and remove credentials:

tsh db logout my-redshift

Troubleshooting

Certificate error

If your tsh db connect error includes the following text, you likely have an RDS 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:

  • An IAM role is used as db_user when accessing AWS services that require IAM roles as database users, such as DynamoDB, Keyspaces, Opensearch, 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 assume_role_arn first then using that IAM role to assume the IAM role for db_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/database-service-role/i-* is not authorized to perform: sts:AssumeRole on resource: arn:aws:iam::111111111111:role/database-user-role

To allow IAM Role role1 to assume IAM Role role2, the following is generally required:

role1 or its AWS account should be set as Principal in role2's trust policy.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::aws-account-id:role/role1"
      },
      "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/role1"
      },
      "Action": "sts:AssumeRole",
      "Condition": {
        "StringEquals": {
          "sts:ExternalId": "example-external-id"
        }
      }
    }
  ]
}

role1 requires sts:AssumeRole permissions, for example:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": "sts:AssumeRole",
            "Effect": "Allow",
            "Resource": "arn:aws:iam::aws-account-id:role/role2"
        }
    ]
}

Note that this policy can be omitted when role1 and role2 are in the same AWS account and role1's full ARN is configured as Principal in role2's trust policy.

role1 also requires sts:AssumeRole permissions in its boundary policy, for example:

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

Note that this is only required when a boundary policy is attached to role1.

You can test the trust relationship by running this AWS CLI command as role1:

aws sts assume-role --role-arn arn:aws:iam::111111111111:role/role2 --role-session-name test-trust-relationship

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

Maximum policy size exceeded errors

Due to IAM and STS character limits, you may encounter one of the following errors in the Database Service logs when large numbers of databases are registered:

  • LimitExceeded: Maximum policy size of 2048 bytes exceeded for user <iam-user>
  • LimitExceeded: Maximum policy size of 10240 bytes exceeded for role <iam-role>

For reference, a user policy can maintain permissions for approximately 6 Redshift databases, or 20 RDS databases due to the IAM policy character limits. A role policy can maintain permissions for approximately 30 Redshift databases, or 100 RDS databases.

To get around this limit, try using one or a combination of the following methods:

You can reduce the policy size by separating them into multiple IAM roles. Use assume_role_arn to specify different IAM roles for accessing the databases:

You can specify assume_role_arn in the AWS matchers of Discovery Service's configuration:

discovery_service:
  enabled: "yes"
  aws:
    - types: ["rds"]
      regions: ["us-west-1", "us-west-2"]
      assume_role_arn: "arn:aws:iam::123456789012:role/example-role-rds-env-prod-discovery"
      tags:
        "env": "prod"

    - types: ["redshift", "redshift-serverless"]
      regions: ["us-west-2"]
      assume_role_arn: "arn:aws:iam::123456789012:role/example-role-redshift-env-dev"
      tags:
        "env": "dev"

The Discovery Service will use the IAM roles specified in assume_role_arn for discovery, and by default the Database Service will use the same IAM roles for authentication.

However, you can also overwrite the IAM roles for authentication by Database Service if you wish to use different roles:

db_service:
  enabled: "yes"
  resources:
    # Matches us-west-1 env=prod RDS databases from Discovery Service, and
    # overwrites assume_role_arn.
    - labels:
        "env": "prod"
        "region": "us-west-1"
      aws:
        assume_role_arn: "arn:aws:iam::123456789012:role/example-role-rds-env-prod-us-west-1-access"

    # Matches us-west-2 env=prod RDS databases from Discovery Service, and
    # overwrites assume_role_arn.
    - labels:
        "env": "prod"
        "region": "us-west-2"
      aws:
        assume_role_arn: "arn:aws:iam::123456789012:role/example-role-rds-env-prod-us-west-2-access"

    # Matches env=dev Redshift databases from Discovery Service and inherits
    # "arn:aws:iam::123456789012:role/example-role-redshift-env-dev"
    - labels:
        "env": "dev"
Auto-discovery labels

Teleport generates certain labels derived from the cloud resource attributes during discovery. See Auto-Discovery labels /labels/#auto-discovery) for more details.

Create or print the required IAM policies with the following commands and attach them to the respective IAM roles:

teleport db configure aws create-iam --types redshift,redshift-serverless --name teleport-redshift-access
teleport db configure aws print-iam --types redshift,redshift-serverless

Refer to the command usage for a complete list of database types supported by the --types option.

You can specify assume_role_arn in the AWS matchers of Database Service's configuration:

db_service:
  enabled: "yes"
  aws:
    - types: ["rds"]
      regions: ["us-west-1", "us-west-2"]
      assume_role_arn: "arn:aws:iam::123456789012:role/example-role-rds-env-prod"
      tags:
        "env": "prod"

    - types: ["redshift", "redshift-serverless"]
      regions: ["us-west-2"]
      assume_role_arn: "arn:aws:iam::123456789012:role/example-role-redshift-env-dev"
      tags:
        "env": "dev"

The Database Service will use the IAM roles specified assume_role_arn for both discovery and authentication.

To bootstrap IAM permissions, run the bootstrap command for each assume_role_arn:

teleport db configure bootstrap \ -c /etc/teleport.yaml \ --policy-name teleport-policy-rds-env-prod \ --attach-to-role "arn:aws:iam::123456789012:role/example-role-rds-env-prod"

You can specify aws.assume_role_arn when defining databases in Database Service's configuration:

db_service:
  enabled: "yes"
  databases:
  - name: "rds-postgres"
    protocol: "postgres"
    uri: "rds-postgres.abcdef012345.us-west-1.rds.amazonaws.com:5432"
    aws:
        assume_role_arn: "arn:aws:iam::123456789012:role/example-rds-access-role"

To bootstrap IAM permissions, run the bootstrap command for each assume_role_arn:

teleport db configure bootstrap \ -c /etc/teleport.yaml \ --policy-name teleport-policy-rds-access \ --attach-to-role "arn:aws:iam::123456789012:role/example-rds-access-role"

You can specify aws.assume_role_arn when defining databases:

kind: db
version: v3
metadata:
  name: "rds-postgres"
  labels:
    env: "dev"
spec:
  protocol: "postgres"
  uri: "rds-postgres.abcdef012345.us-west-1.rds.amazonaws.com:5432"
  aws:
    assume_role_arn: "arn:aws:iam::123456789012:role/example-rds-access-role"

Alternatively, you can overwrite the IAM roles for authentication by Database Service:

db_service:
  enabled: "yes"
  resources:
    # Matches env=dev databases and overwrites assume_role_arn.
    - labels:
        "env": "dev"
      aws:
        assume_role_arn: "arn:aws:iam::123456789012:role/example-env-dev-access"

    # Matches env=prod database, and use the assume_role_arn in the database's
    # definition or use the host IAM identity if assume_role_arn is empty.
    - labels:
        "env": "prod"

Create or print the required IAM policies with the following commands and attach them to the respective IAM roles:

teleport db configure aws create-iam --types rds --name teleport-rds-access
teleport db configure aws print-iam --types rds

Refer to the command usage for a complete list of database types supported by the --types option.

The IAM roles specified in assume_role_arn must trust the IAM identity of the host running the Database Service.

The assume_role_arn is not limited to the same AWS account so you can also use this feature for AWS Cross-Account Access.

You can manually manage IAM policies for database connections instead of relying on the Database Service to update them.

For example, you can limit the character size by attaching a policy with a wildcard "*" for "Resource":

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "rds-db:connect",
            "Resource": "*"
        }
    ]
}
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "redshift:GetClusterCredentials",
            "Resource": "*"
        }
    ]
}

You can safely remove the inline policy created by the Database Service and the IAM permissions for the Database Service to Get/Put/Delete the user or role policy.

You can deploy the Database Service in a highly available (HA) configuration where databases can be sharded to separate Database Services with different IAM roles.

IAM users have a lower character limit compared to IAM roles. If the limit is exceeded for a user policy, it is recommended to use IAM roles for the Database Service instead.

Unable to cancel a query

If you use a PostgreSQL cli client like psql, and you try to cancel a query with ctrl+c, but it doesn't cancel the query, then you need to connect using a tsh local proxy instead. When psql cancels a query, it establishes a new connection without TLS certificates, however Teleport requires TLS certificates not only for authentication, but also to route database connections.

If you enable TLS Routing in Teleport then tsh db connect will automatically start a local proxy for every connection. Alternatively, you can connect via Teleport Connect which also uses a local proxy. Otherwise, you need to start a tsh local proxy manually using tsh proxy db and connect via the local proxy.

If you have already started a long-running query in a psql session that you cannot cancel with ctrl+c, you can start a new client session to cancel that query manually:

First, find the query's process identifier (PID):

SELECT pid,starttime,duration,trim(user_name) AS user,trim(query) AS query FROM stv_recents WHERE status = 'Running';

Next, gracefully cancel the query using its PID. This will send a SIGINT signal to the postgres backend process for that query:

SELECT pg_cancel_backend(<PID>);

You should always try to gracefully terminate a query first, but if graceful cancellation is taking too long, then you can forcefully terminate the query instead. This will send a SIGTERM signal to the postgres backend process for that query:

SELECT pg_terminate_backend(<PID>);

See the PostgreSQL documentation on admin functions for more information about the pg_cancel_backend and pg_terminate_backend functions.

SSL SYSCALL error

You may encounter the following error when your local psql is not compatible with newer versions of OpenSSL:

tsh db connect --db-user postgres --db-name postgres postgres
psql: error: connection to server at "localhost" (::1), port 12345 failed: Connection refused Is the server running on that host and accepting TCP/IP connections?connection to server at "localhost" (127.0.0.1), port 12345 failed: SSL SYSCALL error: Undefined error: 0

Please upgrade your local psql to the latest version.

Next steps