LFD259 - 5.17 ConfigMaps - How is "optional" used?

agstemen

I see both in the course and the kubernetes documentation for the optional flag of a ConfigMap, this information:

You must create a ConfigMap before referencing it in a Pod specification (unless you mark the ConfigMap as “optional”).

My question is, what's a scenario that would benefit from this feature?

chrispokorni

Hi, the statement means that there may be a case when the configMap is not defined. Referencing an undefined configMap prevents the pod from starting. If you have the configMap reference marked as optional, in the case of an undefined configMap the pod still starts. It is a failsafe option when referencing configMaps, ensuring that the pods run either way.

Regards,
-Chris