Are Kubernete's ConfigMaps Writable?

Question

Is it possible to directly modify the file mounted by configMap? We have an application that reads a configuration file that was configMap type and

Answer 1

Yes a configmap is not intended to be writeable. If you're interacting with files from a configmap then you could instead put the files in a writeable volume and mount the volume. Or you could, as you suggest, use centralised configuration like consul. Given, that the app is dynamically writing to this data you could consider it state rather than configuration. Then it could be stored in a database. Another option could be a distributed cache such as redis or hazelcast.