it would be nice to use declarative pipeline to refer to a named podTemplate like in JENKINS-48140 but be able to override any part of the podTemplate with app-specific stuff. e.g. if a particular app wanted to use a custom maven version - while reusing the same global podTemplate configuration.

e.g. something like

pipeline {
  agent {
    kubernetes {
      overridePodTemplate {
        name "fabric8-maven"
        containerTemplate {
          name "maven"
          image "maven:3.5.1"
        }
      }
    }
  }
...
}

i.e. it'd reuse the podTemplate called "fabric8-maven" configured in Manage Jenkins -> Configure System -> Cloud -> Kubernetes -> Pod Templates

then in this case it'd override the image for the container called maven

I'd be able to do a PR myself for this only am not sure how to represent the `overridePodTemplate` class so that it can have > 1 `containerTemplate expressions to override all possible containerTemplates on the podTemplate in declarative markup.

Though I noticed the inheritFrom property on podTemplate so I wonder if something like this is meant to work?

pipeline {
  agent {
    kubernetes {
      podTemplate {
        inheritFrom "fabric8-maven"
        containerTemplate {
          name "maven"
          image "maven:3.5.1"
        }
      }
    }
  }
...
}