Database Access with ClickHouse

• A self-hosted deployment of ClickHouse Server v22.3 or later.

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

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

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 Clickhouse 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.

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-v16.4.8.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 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.

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 Teleport Database Service with systemctl status teleport and view its logs with journalctl -fu teleport.

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