How to build dotnet core in Docker?

Hi I am trying to build my dotnet core 2.1 app using docker. Whenever i create project template default docker file gets generated. This docker file runs fine but whenever I want to upload it to ecr this will not work. So I changed docker file as below.

FROM microsoft/dotnet:2.1-sdk AS build
ENV ASPNETCORE_URLS http://*:44319
EXPOSE 44319
WORKDIR /src
COPY ["LocationServicesAPI/LocationServicesAPI.csproj", "LocationServicesAPI/"]
RUN dotnet restore "LocationServicesAPI/LocationServicesAPI.csproj"
WORKDIR /app/LocationServicesAPI
COPY . .
RUN dotnet build "LocationServicesAPI.csproj" -c Release -o /app

Whenever I run using Docker I get the below error.

1>Step 9/19 : EXPOSE 44319
1> ---> Using cache
1> ---> 069a0777f156
1>Step 10/19 : WORKDIR /src
1> ---> Using cache
1> ---> 6e9768b88723
1>Step 11/19 : COPY ["LocationServicesAPI/LocationServicesAPI.csproj", "LocationServicesAPI/"]
1> ---> Using cache
1> ---> 37b9e63b9b97
1>Step 12/19 : RUN dotnet restore "LocationServicesAPI/LocationServicesAPI.csproj"
1> ---> Using cache
1>Step 13/19 : WORKDIR /app/LocationServicesAPI
1> ---> f505d07f4d8c
1> ---> Using cache
1> ---> e03aaf3a0d7d
1>Step 14/19 : COPY . .
1> ---> 20b8bb0d74bd
1>Step 15/19 : RUN dotnet build "LocationServicesAPI.csproj" -c Release -o /app
1> ---> Running in f04182972995
1>Copyright (C) Microsoft Corporation. All rights reserved.
1>
1>Microsoft (R) Build Engine version 16.1.76+g14b0a930a7 for .NET Core
1>MSBUILD : error MSB1009: Project file does not exist.
1>Switch: LocationServicesAPI.csproj
1>Removing intermediate container f04182972995
1>The command '/bin/sh -c dotnet build "LocationServicesAPI.csproj" -c Release -o /app' returned a non-zero code: 1
1>C:\Users\ngodbole\Documents\MerchWebServices\LocationServicesAPI\LocationServicesAPI\Dockerfile : error CTC1014: Docker command failed with exit code 1.
1>C:\Users\ngodbole\Documents\MerchWebServices\LocationServicesAPI\LocationServicesAPI\Dockerfile : error CTC1014: The command '/bin/sh -c dotnet build "LocationServicesAPI.csproj" -c Release -o /app' returned a non-zero code: 1
1>Done building project "LocationServicesAPI.csproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Below error I am getting after correcting the path.

1> ---> cc58805dac5d
1>Step 14/19 : COPY . .
1> ---> ced094b3788d
1>Step 15/19 : RUN dotnet build LocationServicesAPI.csproj -c Release -o /app
1> ---> Running in 290429a9f4d1
1>Microsoft (R) Build Engine version 16.1.76+g14b0a930a7 for .NET Core
1>Copyright (C) Microsoft Corporation. All rights reserved.
1>
1>Switch: LocationServicesAPI.csproj
1>MSBUILD : error MSB1009: Project file does not exist.

I am not able to figure it out. Can someone help me to fix this? Any help would be appreciated. Thanks

Solution

In your Dockerfile you are copying the code into the wrong folder:

WORKDIR /src
COPY ["LocationServicesAPI/LocationServicesAPI.csproj", "LocationServicesAPI/"]
RUN dotnet restore "LocationServicesAPI/LocationServicesAPI.csproj"

WORKDIR /app/LocationServicesAPI

COPY . .
RUN dotnet build "LocationServicesAPI.csproj" -c Release -o /app

The second WORKDIR command needs to be:

WORKDIR /src/LocationServicesAPI

This will make sure you copy the source code into the same folder as the .csproj

EDIT

You need to move the WORKDIR /src/LocationServicesAPI to after the COPY command so that the build command is executed in the same folder as the .csproj

WORKDIR /src
COPY ["LocationServicesAPI/LocationServicesAPI.csproj", "LocationServicesAPI/"]
RUN dotnet restore "LocationServicesAPI/LocationServicesAPI.csproj"
COPY . .

WORKDIR /src/LocationServicesAPI

RUN dotnet build "LocationServicesAPI.csproj" -c Release -o /app