The more details of docker implentation of PRPC at pega we may not be able to expose through forum as it is internal to pega & it is a customised implementation/architecture. As mentioned in the other thread , you can have a docker for PRPC and internally you can get connected to the postgress DB. Once the connectivity has been established, you are good to go.
For your infrastructure relatd issues, could you please provide the docker name & version? We would try our level best to help you .