remove default configs for the Brokers ?

[matzew]

Problem

current BOTH borker impls come with some ConfigMap that sets them as default.

This is different how channels are handling it.

Perhaps we can follow that model from the channel? to explicitly have the user decide when applying a "yaml distribution" for a channel if she wants that as a default?

** Proposal / Problem **

The brokers both, come with the same configmap, with different values:

https://storage.googleapis.com/knative-nightly/eventing/latest/mt-channel-broker.yaml
https://storage.googleapis.com/knative-nightly/eventing/latest/channel-broker.yaml

so if you apply the first "distributiion", than the second "distribution, they do have effect. the later overrides the default of the first.

Currently our Channels do not do that....

No config maps in here, which does SET the channel as default

• https://github.com/knative/eventing/tree/master/config/channels/in-memory-channel
• https://github.com/knative/eventing-contrib/tree/master/natss/config
• https://github.com/knative/eventing-contrib/tree/master/kafka/channel/config

Instead we have DOC that shows how to update the related configmap to set a channel of choice as the default.

Should we do this too, @vaikas ?

[grantr]

The current scheme for default channels is:

• In eventing-core.yaml, include a configmap that assumes InMemoryChannel is the default, but don't install InMemoryChannel.
• In eventing.yaml include core and the InMemoryChannel.

User scenarios:

• Anyone who installs eventing.yaml has a default channel out of the box.
• Anyone who installs eventing.yaml and another channel MAY update the config to set the default channel.
• Anyone who installs eventing-core.yaml MUST install a channel and update the config (if they want to use default channels).