unable to run a net core docker container - docker

Question

After refactoring from docker-compose into separate Docker file for each project, I'm Unable to run the container, it simply exits. I'm using both docker and docker-compose since I'll have more projects down the road.
My docker files are as follows.
docker-compose.yml
version: '3'
services:
customer:
image: customer
container_name: customer
build:
context: ./Customer
dockerfile: Dockerfile
Customer/Dockerfile
FROM mcr.microsoft.com/dotnet/core/runtime:2.2
WORKDIR /Customer
EXPOSE 80
COPY ./bin/Release/netcoreapp2.2/ service/
ENTRYPOINT ["dotnet", "service/Customer.dll"]
Also I had this within docker-compose file before. How do I map 6001 to 80 within Dockerfile?
ports:
- 6001:80
Attempt 2
FROM mcr.microsoft.com/dotnet/core/sdk:2.2
WORKDIR /Customer
ENV DATABASE_HOST=database
ENV DATABASE_NAME=db
ENV DATABASE_USER=sa
ENV DATABASE_PASSWORD=Password
EXPOSE 80
COPY . .
CMD dotnet build
ENTRYPOINT ["dotnet", "Customer/bin/Release/netcoreapp2.2/Department.dll"]
Attempt 3
copied from main site.
Copied from here https://docs.docker.com/engine/examples/dotnetcore/
FROM mcr.microsoft.com/dotnet/core/sdk:2.2 AS build-env
WORKDIR /app
# Copy csproj and restore as distinct layers
COPY *.csproj ./
RUN dotnet restore
# Copy everything else and build
COPY . ./
RUN dotnet publish -c Release -o out
# Build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:2.2
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "aspnetapp.dll"]
Did you mean to run dotnet SDK commands? Please install dotnet SDK
from: https://go.microsoft.com/fwlink/?LinkID=798306&clcid=0x409

Answer 1

Here is a lazy and basic docker file. I added some comments and some helpful build/debug options, e.g: "RUN ls -al" to list the current directory. Just like a linux VM.
# step 1 - building you app with SDK as base image
FROM microsoft/dotnet:2.2-sdk AS build-env # call the environment build
WORKDIR /build # create a work dir
COPY . . # you don't need copy everything to build your app, but this is for simplisity
RUN ls -al # linux command to list dir content
RUN cd /Customer && dotnet publish -o out # actually building the app and publishing to /out dir
RUN cd /Customer && ls -al # navigate to the folder you copied and list dir
FROM microsoft/dotnet:2.2-aspnetcore-runtime AS runtime # step 2, runtime env (slimmed down container)
WORKDIR /app # create workdir
COPY --from=build-env /<YOUR_BULD_PATH>/out ./ # copy from prev container build output
RUN ls -al # list again
ENTRYPOINT ["dotnet", "Department.dll", "--urls", "http://*:6001"] # example from .NET Core 2.2 webapi with port 6005, this might not be your case
Now to run the docker-compose, just point out the docker file like you have already done. But both docker/docker-compose should work just fine now. Ofcourse you need to tweak the docker file a bit, i dont know your app or folder structure.
And just a tip, if you want to run your docker file as stand alone, dont forget the args when you start it to map ports --> -p 6001:80