[exporter/clickhouse] Fix database creation

[lim123123123]

Description

In the current version of the exporter, the createDatabase function uses cfg.buildDSN, which appends the database from the config into the dsn that is passed into the clickhouse driver.
As a result, the exporter tries to connect to the database before it is actually created, causing a ClickHouse exception in the start function

This pr couldn't be merged until the integration test fix

Testing

I've added an integration test that checks whether the database was successfully created. It fails now but works with the fix.

[atoulme]

I only see changes to tests and the example. What is the fix?

[lim123123123]

I only see changes to tests and the example. What is the fix?

The fix is in exporter/clickhouseexporter/exporter_logs.go
It's actually pretty small, you just shouldn't pass the database into dsn inside createDatabase function
Sorry, if it's not clear from the pr description

[atoulme]

OK, that makes sense. Please add a changelog with make chlog-new and mark the PR as ready for review.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[lim123123123]

I've added the changelog entry. I also disabled the integration tests (as they were before this PR) because they are flaky and the integration tests fix hasn't been merged yet.

Ideally, it would be best to merge the fix first to avoid conflicts (if we merge this PR first, I’ll have to resolve conflicts and go through approvals again). However, the review is taking longer than expected, so let's go ahead and try to fix this bug now

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[lim123123123]

Could someone please review the pr? @dmitryax, @Frapschen, @hanjm, @SpencerTorres
@atoulme, what can I do to remove the 'stale' label? The pr is ready for review, but it seems like no one wants to review it.

[SpencerTorres]

I see the problem, but the fix is a bit confusing. Perhaps we should just change buildDSN to not apply the database at all. We always specify it while inserting, so we never really need to switch to the database at the connection level.

This works though, and I want the users to be unblocked. We can merge it as is

[lim123123123]

I see the problem, but the fix is a bit confusing. Perhaps we should just change buildDSN to not apply the database at all. We always specify it while inserting, so we never really need to switch to the database at the connection level.

This works though, and I want the users to be unblocked. We can merge it as is

I understand your idea—it might actually make sense to simply set the database in each query. However, I don't see the database being set in inserts. Inserts only use the table name, so it's not currently possible to just remove the database from buildDSN now