For running an ASP.NET Core application, I generated a dockerfile which build the application and copys the source code in the container, which is fetched by Git using Jenki
You can run build for a specific service by running docker-compose up --build where the service name must match how did you call it in your docker-compose file.
Example
Let's assume that your docker-compose file contains many services (.net app - database - let's encrypt... etc) and you want to update only the .net app which named as application in docker-compose file.
You can then simply run docker-compose up --build application
Extra parameters
In case you want to add extra parameters to your command such as -d for running in the background, the parameter must be before the service name:
docker-compose up --build -d application