Taking inspiration from what has been done for IAM:

https://github.com/indigo-iam/iam/blob/edfd9d83ede8fbb5ca48208ae4ef8623028fa698/Jenkinsfile

Note that the Jenkinsfile had to restrucuture to "nest" the agent definition is the stages, since that's the only way I found to make the Jenkins agent behave when switching from the K8S slave to the docker SSH slave. A similar approach must be followed in configurations that first build on k8s and then create the images on the dedicated docker SSH slave