Add support for Kafka Alert Node as part of Kapa 1.5

[russorat]

Here are the options for the Kafka config page:

[[kafka]]
  # Configure Kafka
  enabled = false
  # ID is a unique identifier for this kafka cluster.
  id = "localhost"
  # Brokers is a list of host:port addresses of Kafka brokers.
  brokers = []
  # Timeout on network operations with the brokers.
  # If 0 a default of 10s will be used.
  timeout = 10s
  # BatchSize is the number of messages that are batched before being sent to Kafka
  # If 0 a default of 100 will be used.
  batch-size = 100
  # BatchTimeout is the maximum amount of time to wait before flushing an incomplete batch.
  # If 0 a default of 1s will be used.
  batch-timeout = 1s
  # Use SSL enables ssl communication.
  # Must be true for the other ssl options to take effect.
  use-ssl = false
  # Path to CA file
  ssl-ca = ""
  # Path to host cert file
  ssl-cert = ""
  # Path to cert key file
  ssl-key = ""
  # Use SSL but skip chain & host verification
  insecure-skip-verify = false

[jaredscheib]

This appears to address the Kafka config but not configuring a specific alert handler, so a few questions:

1. Are all of these options for the global config?
2. If so, are there any handler-specific options?
3. And which options, if any, do we want to provide handler-specific overrides to global config options for?
4. Is the enabled option available in Kapacitor 1.5 global configs? I've only seen this for specific handlers. Is this blocked on add the ability to enable/disable an alert node config #3292?

[russorat]

1. Initial docs are here https://github.com/influxdata/docs.influxdata.com/blob/refactor/alert-handler-docs/content/kapacitor/v1.5/event_handlers/kafka.md

I think there are things you can build without #3292 so I don’t think this is blocked

[jaredscheib]

Thanks. I asked about being blocked because in #3292 it says:

required for #2786 and #2904

[russorat]

• verify kafka topic and template can be set via the UI.