use kapacitor alert details as opsgenie description text

[JamesClonk]

This is a breaking change in the OpsGenie plugin behaviour of Kapacitor. The modification will use alert/event state details as description when opening OpsGenie alerts instead. This allows much more descriptive alerts in OpsGenie. Alert details in OpsGenie are still filled with the same key/values as before.

The current behaviour of simply encoding the event details as description is imho not very useful as a value for an OpsGenie alert description, Kapacitor alert details can provide much more information and are more in line with OpsGenie alert descriptions.

Would such a change make sense, or is it too breaking in current behaviour?

Required for all non-trivial PRs

• Rebased/mergable
• Tests pass
• CHANGELOG.md updated
• Sign CLA (if not already signed)

[docmerlin]

@JamesClonk With this kind of breaking change, it would be a good idea to add a method to the node that tells it to do this behavior, so the new behavior is optional.

[JamesClonk]

@docmerlin Makes sense, I'll have a look at it.

[docmerlin]

We need a method on the node so you can select the breaking behavior while defaulting to current behavior.

[JamesClonk]

@docmerlin I'm trying to figure out how to do that exactly. Is it enough to just add a field to the Config struct, does that automatically also add a method on the OpsGenie event handler node (It seems that way but I'm not 100% sure)?