Common config in Kubernetes ConfigMap

kubernetes configuration devops configuration-management

There are two ways to do that.

Kustomize - Customization of kubernetes YAML configurations (developed as kubernetes sigs, and had been integrated into kubectl command line). But currently it isn't mature enough if compare with helm chart

https://github.com/kubernetes-sigs/kustomize

Helm chart - The Kubernetes Package Manager. Its vaules.yaml can define the vaule for same configuration files (in your case, they are configmap) with variables.

https://helm.sh/