Create custom event schemas table for new projects

Problem to solve

Users would like to be able to create their own custom events, and view these on their analytics dashboards. The problem is that right now we don't provide an easy way to do that. We can support event names through manually created YAML schemas, but nothing advanced.

We have already implemented a similar system for funnels: https://gitlab.com/gitlab-org/analytics-section/analytics-configurator/-/issues/30+.

Proposed solution

We should create a new configurator endpoint which accepts custom event definitions submitted from .com (configurator is already .com-only access) and stores these definitions in the Clickhouse database. Cube will then retrieve these definitions from Clickhouse directly.

See the parent epic for the overarching plan.

This issue is only related to creating the clickhouse tables for new projects during project setup.

Table structure

The proposed table structure would look something like:

custom_event_schemas

Field name	Field type	Required
name	String	true
title	String	false
description	String	false
props	string	true
created_at	DateTime64(3, 'GMT')	true

With the primary key of PRIMARY KEY name.

CREATE TABLE custom_event_schemas
(
    name        String,
    title       String,
    description String,
    props       String # A JSON string,
    created_at  DateTime64(3, 'GMT')
)
    ENGINE = MergeTree
        PRIMARY KEY name;

Having the created_at and updated_at gives us information for debugging and auditing purposes. I've opted for using the name as the primary key, but we could also require the user to define an ID instead.

Implementation plan

In analytics-manager

• Add a new sql query to create custom_event_schemas table and call this query in the SetupProject