Make clickhouse usage more configurable

[TheErk]

Describe the feature or potential improvement

In current code Langfuse use hardcoded clickhouse parameters.
Namely:

• the clickhouse database name is not configurable, "default" is used (cf: https://github.com/langfuse/langfuse/blob/main/packages/shared/src/server/clickhouse/client.ts#L13)
• the clickhouse cluster name is not configurable, "default" is used (cf: https://github.com/langfuse/langfuse/blob/main/packages/shared/clickhouse/migrations/clustered/0001_traces.down.sql#L1 and many other places)

We would like to make them configurable with

CLICKHOUSE_CLUSTER_NAME
CLICKHOUSE_DB_NAME

Additional information

When deploying a self-hosted instance of Langfuse v3 we need to share an existing instance of clickhouse.
In order to ensure separation of privilege we want to to be able to use:

• a separate DB for clickhouse
• a specifically configured cluster

[marcklingen]

Thanks for sharing, this was just added by @Steffen911 in https://github.com/langfuse/langfuse/releases/tag/v3.6.0

CLICKHOUSE_DB is a native setting that is easily available and with some extra steps you can set CLICKHOUSE_CLUSTER_NAME.

Docs: https://langfuse.com/self-hosting/infrastructure/clickhouse#configuration