CLOUDP-196371: Delete users removed from the resource

[mateigrigore]

Summary:

This PR adds changes that will cleanup connection string secrets after a user is removed from the resource and ensure that it will also be removed from the database.

Connection string secrets are removed by comparing the lastAppliedSpec with the current spec to retrieve the users that have been removed and then their corresponding connection string secrets.

Users are deleted from the database by adding a corresponding DeletedUser object to the usersDeleted field in the auth object of the AutomationConfig. This ensures the users will be deleted according to the documentation

The PR adds:

• 2 new methods in the controllers/mongodb_cleanup.go file:
  • getConnectionStringSecretsToDelete that compares the previous spec with the current one and returns a slice containing the secrets corresponding to removed users
  • cleanupConnectionStringSecrets that deletes the secrets returned by the previous method
• The lastAppliedSpec parameter to r.deployMongoDBReplicaSet, r.deployAutomationConfig, r.ensureAutomationConfig, r.buildAutomationConfig to allow it to be used to retrieve removed users
• 2 new methods in the pkg/authentication/authentication.go file:
  • getDeletedUsers that usses lastAppliedSpec to return a slice of DeletedUsers corresponding to the removed users from the spec
  • AddRemovedUsers that adds the users returned by the previous method to the usersDeleted field in the auth
• The UsersDeleted field to the Auth type. This contains of a slice of objects of type DeletedUser, which contain 2 fields:
  • User: The user that will be deleted
  • Dbs: A list of databses from which the user should be deleted
• 3 methods in the test/e2e/mongodbtests/mongodbtests.go file:
  • RemoveUserFromResource that sets the users field in the spec of the resource to an empty list
  • ConnectionStringSecretsAreCleanedUp that checks that a specific connection string secret is not found in the cluster anymore
  • AuthUsersDeletedIsUpdated that checks that the auth was updated to contain the specified user
• An e2e test to check the behaviour of cleaning up users that:
  • Creates a MongoDBCommunity resource
  • Asserts basic functionality of that resource
  • Removed the users from it
  • Waits for the resource to be ready
  • Checks for the auth to be updated
  • Checks for the connection string secret to be deleted
  • Deletes the resource

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[nammn]

Thanks for your changes! They are looking good! Just some suggestions here and there

[nammn]

Thanks for your contribution, LGTM! One small cleanup and we should be good to go once all tests are green