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Database Access with ClickHouse

The Teleport Clickhouse integration allows you to enroll ClickHouse databases with Teleport.

This guide will help you to:

  • Install and configure a Teleport database agent.
  • Set up Teleport to access your self-hosted ClickHouse database.
  • Connect to your database through Teleport.

How it works

The Teleport Database Service authenticates to ClickHouse using x509 certificates, which are available for the ClickHouse HTTP and Native (TCP) interfaces. The Teleport Database Service can communicate in both the ClickHouse Native (TCP) and HTTP protocols, and you can select which protocol to use when configuring the Teleport Database Service.

Teleport audit logs for query activity are only supported for the ClickHouse HTTP interface. Teleport support for ClickHouse's native interfaces does not include audit logs for database query activity.

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.

  • Either a Linux host or Kubernetes cluster where you will run the Teleport Database Service.

You will also need the following, depending on the ClickHouse protocol you choose:

  • A self-hosted deployment of ClickHouse Server v22.3 or later.
  • A self-hosted deployment of ClickHouse Server v23.3 or later.
  • The clickhouse-client installed and added to your user's PATH environment variable.
  • Optional: a certificate authority that issues certificates for your self-hosted database.

Step 1/5. Create a Teleport token and user

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
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 2/5. Create a certificate/key pair

Teleport uses mutual TLS authentication with self-hosted databases. These databases must be able to verify certificates presented by the Teleport Database Service. Self-hosted databases also need a certificate/key pair that Teleport can verify.

By default, the Teleport Database Service trusts certificates issued by a certificate authority managed by the Teleport Auth Service. You can either:

  • Configure your self-hosted database to trust this CA, and instruct Teleport to issue a certificate for the database to present to the Teleport Database Service.
  • Configure the Database Service to trust a custom CA.

To configure the database to trust the Teleport CA and issue a certificate for the database, follow these instructions on your workstation:

  1. To use tctl from your workstation, your Teleport user must be allowed to impersonate the system role Db in order to be able to generate the database certificate. Include the following allow rule in in your Teleport user's role:

    allow:
      impersonate:
        users: ["Db"]
        roles: ["Db"]
    
  2. Export Teleport's certificate authority and a generate certificate/key pair. This example generates a certificate with a 1-year validity period. db.example.com is the hostname where the Teleport Database Service can reach the server.

    tctl auth sign --format=db --host=db.example.com --out=server --ttl=2190h
    TTL

    We recommend using a shorter TTL, but keep mind that you'll need to update the database server certificate before it expires to not lose the ability to connect. Pick the TTL value that best fits your use-case.

    The command creates 3 files: server.cas, server.crt and server.key.

If the database already has a CA that it uses to sign certificates , you only need to export a Teleport CA certificate for the database to authenticate traffic from the Teleport Database Service. You do not need to enable Db impersonation privileges.

  1. Replace example.teleport.sh:443 with the host and web port of the Teleport Proxy Service in your cluster. Run the following command on your workstation:

    tctl auth export --type=db-client --auth-server=example.teleport.sh:443 > db-client.cas

    The command creates 1 file, db-client.cas.

  2. Append the contents of db-client.cas to your database's existing CA cert file, which this guide expects to be called server.cas.

  3. Generate server.crt and server.key by retrieving a TLS certificate and private key from your existing database CA, signed for your database server. You will use these files later in the guide.

Step 3/5. Configure ClickHouse

Use the generated secrets to enable mutual TLS in your clickhouse-server/config.xml configuration file:

<openSSL>
    <server>
       <privateKeyFile>/path/to/server.key</privateKeyFile>
       <caConfig>/path/to/server.cas</caConfig>
       <certificateFile>/path/to/server.crt</certificateFile>
       <verificationMode>strict</verificationMode>
    </server>
</openSSL>

Additionally, your ClickHouse database user accounts must be configured to require a valid client certificate:

CREATE USER alice IDENTIFIED WITH ssl_certificate CN 'alice';

By default, the created user may not have access to anything and won't be able to connect, so let's grant it some permissions:

GRANT ALL ON *.* TO alice;

Step 4/5. Configure and start the Database Service

Install and configure Teleport on the host or Kubernetes cluster where you will run the Teleport Database Service. Assign protocol to clickhouse-http for the HTTP protocol and clickhouse for the native ClickHouse protocol:

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.

Note

The step below will overwrite an existing configuration file, so if you're running multiple services add --output=stdout to print the config in your terminal, and manually adjust /etc/teleport.yaml.

On the host where you will run the Teleport Database Service, start Teleport with the appropriate configuration.

Note that a single Teleport process can run multiple different services, for example multiple Database Service agents as well as the SSH Service or Application Service. The step below will overwrite an existing configuration file, so if you're running multiple services add --output=stdout to print the config in your terminal, and manually adjust /etc/teleport.yaml.

Run the following command to generate a configuration file at /etc/teleport.yaml for the Database Service. Update teleport.example.com:443 to use the host and port of the Teleport Proxy Service:

sudo teleport db configure create \ -o file \ --token=/tmp/token \ --proxy=teleport.example.com:443 \ --name=example-clickhouse \ --protocol=protocol \ --uri=clickhouse.example.com:8443 \ --labels=env=dev

To configure the Teleport Database Service to trust a custom CA:

  1. Export a CA certificate for the custom CA and make it available at /var/lib/teleport/db.ca on the Teleport Database Service host.

  2. Run a variation of the command above that uses the --ca-cert-file flag. This configures the Teleport Database Service to use the CA certificate at db.ca to verify traffic from the database:

    sudo teleport db configure create \ -o file \ --token=/tmp/token \ --proxy=teleport.example.com:443 \ --name=example-clickhouse \ --protocol=protocol \ --uri=clickhouse.example.com:8443 \ --ca-cert-file="/var/lib/teleport/db.ca" \ --labels=env=dev

Configure the Teleport 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 Teleport Database Service.

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

sudo systemctl enable teleport
sudo systemctl start teleport

On the host where you will run the Teleport 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 Teleport Database Service with systemctl status teleport and view its logs with journalctl -fu teleport.

Teleport provides Helm charts for installing the Teleport Database Service in Kubernetes Clusters.

Set up the Teleport Helm repository.

Allow Helm to install charts that are hosted in the Teleport Helm repository:

helm repo add teleport https://charts.releases.teleport.dev

Update the cache of charts from the remote repository so you can upgrade to all available releases:

helm repo update

Install a Teleport agent into your Kubernetes Cluster with the Teleport Database Service configuration.

Create a file called values.yaml with the following content. Update teleport.example.com:443 to use the host and port of the Teleport Proxy Service and JOIN_TOKEN to the join token you created earlier:

roles: db
proxyAddr: teleport.example.com:443
# Set to false if using Teleport Community Edition
enterprise: true
authToken: JOIN_TOKEN
databases:
  - name: example-clickhouse
    uri: clickhouse.example.com:8443
    protocol: protocol
labels:
  env: dev

To configure the Teleport Database Service to trust a custom CA:

  1. Export a CA certificate for the custom CA and make it available at db.ca on your workstation.

  2. Create a secret containing the database CA certificate in the same namespace as Teleport using the following command:

    kubectl create secret generic db-ca --from-file=ca.pem=/path/to/db.ca
  3. Add the following to values.yaml:

  roles: db
  proxyAddr: var3a3f85af2ab9442298b8408d7d4141bf
  # Set to false if using Teleport Community Edition
  enterprise: true
  authToken: vara667914f0a0345d1ab1f1cbe123211c6
  databases:
    - name: example-clickhouse
      uri: clickhouse.example.com:8443
      protocol: var2c89df1d3e1640f1ac3a26745028b893
+     tls:
+       ca_cert_file: "/etc/teleport-tls-db/db-ca/ca.pem"
      static_labels:
        env: dev
+ extraVolumes:
+   - name: db-ca
+     secret:
+       secretName: db-ca
+ extraVolumeMounts:
+   - name: db-ca
+     mountPath: /etc/teleport-tls-db/db-ca
+     readOnly: true

Install the chart:

helm install teleport-kube-agent teleport/teleport-kube-agent \ --create-namespace \ --namespace teleport-agent \ --version 16.0.0 \ -f values.yaml

Make sure that the Teleport agent pod is running. You should see one teleport-kube-agent pod with a single ready container:

kubectl -n teleport-agent get pods
NAME READY STATUS RESTARTS AGEteleport-kube-agent-0 1/1 Running 0 32s
Tip

A single Teleport process can run multiple services, for example multiple Database Service instances as well as other services such the SSH Service or Application Service.

Step 5/5. Connect

Once the Database Service has joined the cluster, log in to see the available databases:

Log in to Teleport and list the databases you can connect to. You should see the ClickHouse database you enrolled earlier:

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

Name Description Allowed Users Labels Connect

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

example-clickhouse-http [*] env=dev

Create an authenticated proxy tunnel so you can connect to ClickHouse via a GUI database client, or send a request via curl:

tsh proxy db --db-user=alice --tunnel example-clickhouse-http

Started authenticated tunnel for the Clickhouse (HTTP) database "clickhouse-http" in cluster "teleport.example.com" on 127.0.0.1:59215.

To avoid port randomization, you can choose the listening port using the --port flag.

Use the following command to connect to the database or to the address above using other database GUI/CLI clients:

$ curl http://localhost:59215/

To test the connection you can run the following command:

echo 'select currentUser();' | curl http://localhost:59215/ --data-binary @-

alice

To log out of the database and remove credentials:

Remove credentials for a particular database instance.

tsh db logout example-clickhouse-http

Remove credentials for all database instances.

tsh db logout

Log in to Teleport and list the databases you can connect to. You should see the ClickHouse database you enrolled earlier:

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

Name Description Allowed Users Labels Connect

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

example-clickhouse [*] env=dev

Connect to the database:

tsh db connect --db-user=alice example-clickhouse

ClickHouse client version 22.7.2.1.

Connecting to localhost:59502 as user default.

Connected to ClickHouse server version 23.4.2 revision 54462.

350ddafd1941 :) select 1;

SELECT 1

Query id: 327cfd34-2fec-4e04-a185-79fc840aa5cf

┌─1─┐

│ 1 │

└───┘

↓ Progress: 1.00 rows, 1.00 B (208.59 rows/s., 208.59 B/s.) (0.0 CPU, 9.19 KB RAM)

1 row in set. Elapsed: 0.005 sec.

350ddafd1941 :)

To log out of the database and remove credentials:

Remove credentials for a particular database instance.

tsh db logout example-clickhouse

Remove credentials for all database instances.

tsh db logout

Next steps

  • Take a look at the YAML configuration reference.