HTTP

Documentation for Http

This page isn’t applicable to ClickHouse Cloud. The feature documented here isn’t available in ClickHouse Cloud services. See the ClickHouse Cloud Compatibility guide for more information.

HTTP server can be used to authenticate ClickHouse users. HTTP authentication can only be used as an external authenticator for existing users, which are defined in users.xml or in local access control paths. Currently, Basic authentication scheme using GET method is supported.

HTTP authentication server definition

To define HTTP authentication server you must add http_authentication_servers section to the config.xml.

Example

<clickhouse>
    <!- ... -->
    <http_authentication_servers>
        <basic_auth_server>
          <uri>http://localhost:8000/auth</uri>
          <connection_timeout_ms>1000</connection_timeout_ms>
          <receive_timeout_ms>1000</receive_timeout_ms>
          <send_timeout_ms>1000</send_timeout_ms>
          <max_tries>3</max_tries>
          <retry_initial_backoff_ms>50</retry_initial_backoff_ms>
          <retry_max_backoff_ms>1000</retry_max_backoff_ms>
          <forward_headers>
            <name>Custom-Auth-Header-1</name>
            <name>Custom-Auth-Header-2</name>
          </forward_headers>

        </basic_auth_server>
    </http_authentication_servers>
</clickhouse>

Note, that you can define multiple HTTP servers inside the http_authentication_servers section using distinct names.

Parameters

• uri - URI for making authentication request

Timeouts in milliseconds on the socket used for communicating with the server:

• connection_timeout_ms - Default: 1000 ms.
• receive_timeout_ms - Default: 1000 ms.
• send_timeout_ms - Default: 1000 ms.

Retry parameters:

• max_tries - The maximum number of attempts to make an authentication request. Default: 3
• retry_initial_backoff_ms - The backoff initial interval on retry. Default: 50 ms
• retry_max_backoff_ms - The maximum backoff interval. Default: 1000 ms

Forward headers:

The part defines which headers will be forwarded from client request headers to external HTTP authenticator. Note that headers will be matched against config ones in case-insensitive way, but forwarded as-is i.e. unmodified.

Enabling HTTP authentication in users.xml

In order to enable HTTP authentication for the user, specify http_authentication section instead of password or similar sections in the user definition.

Parameters:

• server - Name of the HTTP authentication server configured in the main config.xml file as described previously.
• scheme - HTTP authentication scheme. Basic is only supported now. Default: Basic

Example (goes into users.xml):

<clickhouse>
    <!- ... -->
    <my_user>
        <!- ... -->
        <http_authentication>
            <server>basic_server</server>
            <scheme>basic</scheme>
        </http_authentication>
    </test_user_2>
</clickhouse>

Note that HTTP authentication cannot be used alongside with any other authentication mechanism. The presence of any other sections like password alongside http_authentication will force ClickHouse to shutdown.

Enabling HTTP authentication using SQL

When SQL-driven Access Control and Account Management is enabled in ClickHouse, users identified by HTTP authentication can also be created using SQL statements.

CREATE USER my_user IDENTIFIED WITH HTTP SERVER 'basic_server' SCHEME 'Basic'

…or, Basic is default without explicit scheme definition

CREATE USER my_user IDENTIFIED WITH HTTP SERVER 'basic_server'

Passing session settings

If a response body from HTTP authentication server has JSON format and contains settings sub-object, ClickHouse will try parse its key: value pairs as string values and set them as session settings for authenticated user’s current session. If parsing is failed, a response body from server will be ignored.