Create webhook to trim messages from the status object

[jpkrohling]

As part of #55, we added a new array of messages to the Status object. For long lived instances, this might potentially become a big list of messages, so, we might want to consider trimming it to the last N messages.

Questions:

• should this be a webhook? This is what makes more sense to me.
• should we add a timestamp to the message?
• should we remove by date, or by number of messages?
• what would be a good age/number to keep?
• should we add another message, saying that older messages have been removed?

[objectiser]

Rather than webhook, can't we just trim at the point a new message is added (i.e. have a common function that appends the messages to the status object and cleans up when necessary)? Think restricting by number may be adequate initially, as it shouldn't happen that often - although I guess it will depend upon how many messages are reported per version upgrade. May be start with 20?

[VineethReddy02]

Rather creating a webhook for this. I think we can add a check in reconcillation flow i.e opentelemetry Self(). If Messages array size is > 10, then drop the oldest messages i.e.

if len(messages) > 10 {
  diff := len(messages) - 10
  messages = messages[diff:]
}

WDYT @jpkrohling

[jpkrohling]

The problem with doing it at the reconciliation is that it will trigger an object update, which will trigger another reconciliation routine. It's not bad per se, but a webhook would probably be cleaner.

Another thing to consider is using events instead of this. We have this pattern introduced recently: #215 (comment)

More on this: https://book-v1.book.kubebuilder.io/beyond_basics/creating_events.html

[jpkrohling]

I'm closing this, as I think we should instead be recording events instead of adding messages for this type of content.