Add Kafka trigger example

[rameshpolishetti]

Current behavior:
Currently, we have only rest trigger based examples

Expected behavior:
Add kafka trigger based example, describing how a Kafka message can be input source to rule action & how kafka topic and messages are mapped to tuple type and data.

[mellistibco]

I don't understand this enhancement request. Flogo Rules should support any Flogo trigger. Why are we suggesting to implement the exact the same thing already implemented in flogo core? If someone wants to trigger a flogo rules app from any source, they should be using flogo rules as an action in a flogo application and hence get the ability to trigger the rules via any available trigger in the flogo ecosystem.

[rameshpolishetti]

@mellistibco It's my bad. I didn't mean to add same Kafka trigger here instead add an example for kafka channel and update rules/action input parameters (for mapping, only if required). Let me update the issue title/description accordingly.

[mellistibco]

i think we need to clean up terminology also. we need to keep things consistent. A channel is basically the same thing as a trigger, can we work on cleaning up terminology both in code and in documentation? I can't think of any reason to have multiple overlapping terms. Flogo has standardized on triggers and we should stick with that as a way to define/describe an input source into an action.

[rameshpolishetti]

@mellistibco agreed, updating the issue terminology accordingly.
Don't want to dilute the original objective of this issue. Can we take up fixing any terminology deviations as a different issue?

[mellistibco]

@rameshpolishetti yes, let's create a different issue to capture and track the larger task of fixing terminology, etc.