accidentially writing "null" instead of null-value to topic

[warmuuh]

This is not necessarily an issue but there could be a safeguard to not accidentially write a null-value or null-key like this:

kafkactl produce my-topic -k "x" -v null

this results in the string "null" to be written to the topic instead of the intended null-value.

It happened now multiple times by different people in my company and always resulted in major problems as there is now a "poison pill" in the topic.

so i thought, it maybe makes sense to add a safeguard for this specific string, such as:

> kafkactl produce my-topic -k "x" -v null
> kafkactl produce my-topic -k null -v "x"
Do you really intend to write the string "null" (tombstones are written using --null-value / --null-key) [y/N]?

[d-rk]

Hey @warmuuh

thats probably a good idea. I was thinking perhaps interpreting null as tombstone per default would be better.
then we would only need a way to write null string for the (probably rare) cases where this is still needed.

Regards,
Dirk