Cld 9544 provisioner fix mysql db connection string

[andrleite]

Summary

This pull request enhances the handling of MySQL database connection strings by adding support for a new "datasource URL" format (without the mysql:// prefix) in the database secret generation and Kubernetes secret creation processes. This change ensures that both the original connection string and the datasource URL are available for use in different contexts, improving compatibility and flexibility.

MySQL connection string improvements:

• Updated the MattermostMySQLConnStrings function to return an additional datasource URL (connection string without the mysql:// prefix), alongside the existing connection string and read replica string.
• Modified both RDSDatabase.GenerateDatabaseSecret and RDSMultitenantDatabase.GenerateDatabaseSecret to capture and store the new datasource URL in the generated secret.

Secret structure and Kubernetes integration:

• Added a new DataSourceURL field to the InstallationDBSecret struct to store the datasource URL.
• Updated the ToK8sSecret method to include the datasource URL as MM_SQLSETTINGS_DATASOURCE in the generated Kubernetes secret if it is present.
• Extended the unit tests in secret_test.go to verify correct handling of the datasource URL in secrets, including cases where it is present and absent.

Secret generation updates:

• Ensured that the new DataSourceURL field is set when generating secrets for both single-tenant and multitenant RDS databases.

Ticket Link

https://mattermost.atlassian.net/browse/CLD-9544

Release Note

fix mysql database connection string

[fmartingr]

Same as the other one, LGTM but I'm not sure why we are fixing MySQL related things. Am I missing context here?

[andrleite]

Same as the other one, LGTM but I'm not sure why we are fixing MySQL related things. Am I missing context here?

We still have a few customers using it, and our QA team is using MySQL to test old versions.