Dotnet Restore fails in docker build

Question

Hello i am trying to dockerize a ASP NET Core 2.1 application and the docker build fails when it executes dotnet restore. I have already checked other threads for this specific problem
Nuget connection attempt failed "Unable to load the service index for source".

The solutions provided there did not help me.

Dockerfile

ARG serverPath=./Core/Server

FROM microsoft/dotnet:sdk AS build-env
WORKDIR /app


COPY ./Core/Server/*.csproj ./
RUN dotnet restore  //fails here

COPY ./Core/Server/ ./
RUN dotnet publish -c Release -o out  


FROM microsoft/dotnet:2.1-aspnetcore-runtime 
WORKDIR /app
COPY --from=build-env /app/out  .
ENTRYPOINT ["dotnet","Server.dll"]

Output of docker build

$ docker build -t server .
Sending build context to Docker daemon  11.13MB
Step 1/11 : ARG serverPath=./Core/Server
Step 2/11 : FROM microsoft/dotnet:sdk AS build-env
 ---> 343e2dc38168
Step 3/11 : WORKDIR /app
 ---> Using cache
 ---> e9b75480ecb9
Step 4/11 : COPY ./Core/Server/*.csproj ./
 ---> Using cache
 ---> 2de864bedf6a
Step 5/11 : RUN dotnet restore 
 ---> Running in 2fc6963e7e2c
  Restoring packages for /app/Server.csproj...
/usr/share/dotnet/sdk/2.2.100/NuGet.targets(114,5): error : Unable to load the service index for source https://api.nuget.org/v3/index.json. [/app/Server.csproj]
/usr/share/dotnet/sdk/2.2.100/NuGet.targets(114,5): error :   The SSL connection could not be established, see inner exception. [/app/Server.csproj]
/usr/share/dotnet/sdk/2.2.100/NuGet.targets(114,5): error :   Authentication failed because the remote party has closed the transport stream. [/app/Server.csproj]
The command '/bin/sh -c dotnet restore -p:RestoreUseSkipNonexistentTargets=false -nowarn:msb3202,nu1503' returned a non-zero code: 1

Answer 1

Try this

docker network ls

This should list the networkIDs try running the docker build

docker build --network=<networkid> tag=<tag>

try the above with all the network listed it will work with one, that's the host network.