Auth: Enable retries and transaction for some db calls for auth tokens

[bergquist]

ref #16638

[bergquist]

Migrating from the old way to using WithDbSession I realized how bad the API is. We need to figure out a better API for this. Its very easy to write code like this

var affected int64
err := srv.SQLStore.WithDbSession(ctx, func(dbSession *sqlstore.DBSession) error {
	// code

	affected, err := res.RowsAffected() 
	return err
})

and create an new variable in that scope instead of assigning the original one.

[marefr]

Just to be clear this doesn't add any retries for sqlite right?

You did a very thorough work getting context in everywhere, but in auth_token.go you forget to use the provided ctx as argument to WithDbSession :)

[torkelo]

Just to understand the db locked issue and how this solves it. Was it caused, you suspect, by opening & not closing sessions?

Wonder if it would be possible to open a session in the middleware at the start and store it in the Request context, and the pass context down to sql layer and have the withDbSession reuse session in the context object. And have the middleware close the session on request completion.

[bergquist]

Fixed the context.Background issues and switched to using transactions (inc retries) for rotation. I was considering adding retries for all WithDbSession requests as well but Im not sure about it. It could potentially create more requests to the db if it's exhausted.

@torkelo yesterday I didn't like that idea but I might have changed my mind. We still need some way of managing session background tasks. Let's discuss that in another issue. I think we need to improve this soon as more people will be working in the backend.

[marefr]

Everything looks good besides some dummy code that seems to have been sneaked in, see comment.

[marefr]

Please remove this 😄

[bergquist]

haha

[marefr]

🎉