Add optional gocql config for customized cassandra connections

[boguth]

For Cassandra connections that might require more information to connect -for example, auth info or SSL options - it's best to use a session established by the user.

[boguth]

@lucasmdrs Slight addition to the original implementation. Let me know if I can answer any questions here.

[boguth]

@fabioserra / @lucasmdrs Gentle ping whenever y'all have a moment :)

[lucasmdrs]

This logic became quite complex and it's a bit unsafe to defer a method before checking the returned error, what do you think about extracting this part into a separate private function that safely returns what you need like this:

func initSession(c Config) (func(), *gocql.Session, error) {
	if c.Session != nil {
		return func() {
			// do not close provided session
		}, c.Session, nil
	}

	if len(c.Hosts) < 1 || len(c.Keyspace) < 1 {
		return nil, nil, errors.New("cassandra cluster config or keyspace name and hosts are required to initialize cassandra health check")
	}

	cluster := gocql.NewCluster(c.Hosts...)
	cluster.Keyspace = c.Keyspace
	session, err := cluster.CreateSession()
	if err != nil {
		return nil, nil, err
	}

	return session.Close, session, err
}

that way you can call it:

shutdown, session, err := initSession(config)
if err != nil {
	return fmt.Errorf("cassandra health check failed on connect: %w", err)
}
defer shutdown()

[boguth]

Completely agreed. I refactored per your suggestions and tested it - all's working. Thanks @lucasmdrs

[lucasmdrs]

Thank you for the contribution! 🚀

[boguth]

@lucasmdrs Happy to contribute and thank you for open-sourcing this! Any ETA on when this'll get merged?

[lucasmdrs]

Done!

I'll merge some other dependencies bump first and release a new version by the end of the week 👍

[boguth]

@lucasmdrs Awesome. I'll keep an eye on it.

[boguth]

@lucasmdrs - very gentle nudge here. Any idea on when the new version with these changes might be released?

[lucasmdrs]

My apologies @boguth, forgot to notify you, this change was already made available in the release v5.4.0

[boguth]

No apologies necessary @lucasmdrs. Thank you!