thank you for response.
In our scenario we build a Nuget package for our application during the build process. After that we use Octopus to create a Docker Image from the generated Nuget package and deploy them over a Tentacle into a Docker Registry. During the build process of the Docker Image we have to add some pfx files into them because they need to be registered inside the Docker Image later. In point of our security rules it is not allowed to add the certificates into the our VCS and we have to add the certificates manually during the build process.
My idea was that i add the certificates before octopus creates the Docker Image at the Tentacle because i have to process some Powershell Commands which are one of the steps in the Dockerfile.