Add custom attribute for server name

[TylerLubeck]

Description of the changes

Hello! This is a different take on the problem I'm trying to solve for in #9. We run multiple instances of redis on a single machine and would like to have a way to differentiate between them in Insights. Historically we've done this with the port number, but specifying a "human friendly" name would work equally well for our purposes.

I'm more than open to other ideas as well, my only real goal is to differentiate between multiple unique redis instances on a single machine

PR Review Checklist

Author

• add a risk label after carefully considering the "blast radius" of your changes
• describe the intent of your changes in the description. don't just rewrite your code in prose
• assign at least one reviewer

Reviewer

• review code for readability
• verify that high risk behavior changes are well tested
• check license for any new external dependency
• ask questions about anything that isn't clear and obvious
• approve the PR when you consider it's good to merge

[TylerLubeck]

Apologies for the whitespace changes. I believe this is the result of gofmt, so I left them in since they'll probably end up here eventually. I can remove them again if you'd like to keep the PR focused on the real changes

[alejandrodnm]

Hi @TylerLubeck first of all thanks for the PR.

Now the bad news, the current implementation of the integration doesn't support monitoring more than one instance. This has to do with the way the data is being processed, is you do this, adding a new attribute that distinguishes between instances, you might end up with collisions between metrics.

The good news is, we have in our roadmap a task for exactly this, allowing the integration to monitor multiple instances. I can not give you an ETA but it's high on our to do list.

I'm going to close both this and #9, but will leave an open issue to notify you once we add support for what you need.